CN114365246B - Data link for resonant inductive wireless charging - Google Patents

Abstract

A full-duplex, low-latency near-field data link controls a resonant inductive wireless power transfer system for recharging a battery. In an electric vehicle embodiment, the component is aligned relative to a ground component to receive a charging signal. The vehicle component includes one or more charging coils and a first full-duplex inductively coupled data communication system that communicates with a ground component that includes one or more charging coils and a second full-duplex inductively coupled data communication system. Based on the geometric positioning of the vehicle component relative to the ground component, the charging coils of the ground component and the vehicle component are selectively enabled for charging. Where appropriate, the transmit/receive systems of the ground component and/or the vehicle component are adjusted to be of the same type to enable communication of charging management and control data between the ground component and the vehicle component during charging.

Description

Data link for resonant inductive wireless charging

Priority statement

The present application claims the benefit of priority from U.S. application Ser. No. 16/675,618, filed on 11/2019, and also claims the benefit of priority from U.S. application Ser. No. 16/570,801, filed on 13/2019, both of which are incorporated herein by reference in their entirety.

Technical Field

Full duplex near field data links intended for controlling resonant inductive wireless power transfer systems are used to recharge electric vehicles. The coherent transponder configuration enables interference-suppressed synchronous detection and positive suppression of signals originating from nearby and neighboring vehicles.

Background

Inductive power transfer has many important applications across many industries and markets. Resonant inductive wireless power devices can be considered as switched mode DC to DC power supplies with large air gap transformers separating and isolating the power supply input and output sections. Since the output current is controlled by adjusting the input side parameter, there must be a method of passing the output parameter to the input side control circuit. Conventional isolated switched mode power supplies use optical couplers or coupling transformers to communicate across the isolation barrier, but these conventional approaches are not useful in situations where large physical gaps exist. Acoustic and optical communication across the power transmission gap is in principle possible but is in practice insufficient when challenged by mud, road debris, snow ice and water accumulation. Communication across the power transfer gap may be made by modulating the receiving inductor impedance and detecting voltage and current variations induced across the primary side inductor. However, due to the generally low operating frequency employed by resonant inductive wireless power transfer devices and the moderate to high load Q values of the primary and secondary side inductors of such resonant inductive wireless power transfer systems, the available data communication bandwidth is severely limited and full duplex communication implementations are difficult.

Thus, a radio frequency based data communication system is preferred because it is not affected by the difficulties listed above, however, conventional radio frequency data communication systems are inadequate in several respects. Half duplex systems transmit in only one direction, but rapidly alternate the direction of transmission, creating a data link that serves as a full duplex link. Transmission data buffering or queuing introduces significant and variable transmission delays, which are particularly undesirable as a cause of control system instability when placed in the control system feedback path.

Conventional superheterodyne receivers typically require a fairly good intermediate frequency filter to provide off-channel interference rejection. However, such filters tend to be expensive and do not lend themselves readily to monolithic integration.

Furthermore, conventional radio data links do not inherently distinguish between other nearby data links of the same type. This means that conventional radio-based data links often respond to radio commands issued by charging devices in nearby or adjacent parking spaces when used to facilitate resolution of wireless charging of electric vehicles, an action that greatly complicates explicit vehicle identification and subsequent wireless charging control.

Disclosure of Invention

The systems and methods described herein address the above and other limitations of the prior art by implementing a coherent full duplex radio frequency data link that relies on near field inductive coupling as opposed to far field propagation in conventional systems to limit the effective communication range, that employs synchronous detection to suppress off-channel and some co-channel interference without complex frequency domain filtering, and that employs a coherent transponder (transponder) architecture for positive identification of data link transmit-receive device pairs.

In an example embodiment, two apparatuses are provided, one associated with a ground-side wireless power transmission device and the other associated with a vehicle-side wireless power reception device. A crystal-controlled reference oscillator located in the ground-side device provides a common basis for coherent generation of all the radio frequency signals required for transmission and detection. Since this is a full duplex communication device, there are two separate transmit-receive links, a forward link from the ground side device to the vehicle side device and a return link from the vehicle side device to the ground side device. The vehicle-side loop antenna is generally located below the bottom of the vehicle's conductive car body and parallel with respect to the ground surface.

The forward link transmission signal is derived from the reference oscillator. Serial data is applied by the modulator to the forward link carrier. Transmission occurs between two electrically small loop antennas with significant mutual inductive coupling, which are spaced far apart less than the wavelength at the forward link operating frequency. On the vehicle side of the forward link, the received signal is detected by a homodyne detector, which extracts the carrier of the signal and uses the carrier of the signal as a detection reference in a synchronous detector. The extracted carriers are multiplied in frequency and used as carriers for the return link, where the return link data is applied to the carrier with the second modulator. The return link transmission occurs through near field inductive coupling between two closely spaced electrically small loop antennas, as previously described. The ground side synchronous detector of the link uses a multiplied version of the original reference oscillator signal as a detection reference to extract the return link data. The link modulation in both directions may be amplitude modulation, phase modulation or a combination of both.

Because the forward link carrier, forward link detection reference, return link carrier, and return link detection reference are all derived from the same reference oscillator, the coherence of these four critical signals is ensured by design. No complex frequency acquisition and synchronization circuitry is required. Furthermore, production tolerances and environmentally induced frequency variations between the reference oscillators ensure that the link signals from devices located in adjacent parking spaces will not be coherent and will therefore not be subject to synchronous detection. Further suppression of link signals originating from devices and vehicles in adjacent parking spaces results from attenuation that occurs when the link transmission wavelength exceeds the separation distance of the underbody of the vehicle from the ground surface, where the underbody of the vehicle and the ground surface act as two plates of the waveguide operating below the waveguide propagation cut-off frequency.

According to a first aspect, there is provided a charging system comprising a first coil assembly comprising a charging coil and a first full duplex inductively coupled data communication system comprising a first transmit/receive system transmitting a first signal over a first inductive link and receiving a second signal over a second inductive link, and a second coil assembly comprising a charging coil and a second full duplex inductively coupled data communication system comprising a second transmit/receive system receiving the first signal over the first inductive link and transmitting the second signal over the second inductive link. In an example embodiment, the first and second transmission/reception systems are adapted to be able to select among at least one of a hardware, software and firmware configuration adapted to modulate an output signal and demodulate an input signal. Further, the charging coil of the first coil assembly is configured to be disposed parallel to the charging coil of the second coil assembly to receive a charging signal during charging and is selectively enabled to match the geometry of the second coil assembly during charging.

In an example embodiment, the first transmit/receive system includes a processor that processes data from at least one of the first coil assembly and the external system for transmission to the second coil assembly and processes data received from the second coil assembly for delivery to at least one of the first coil assembly and the external system for processing. In an example embodiment, the processor disables the charging signal when the first coil assembly detects a fault event or when a fault event is received from the second coil assembly.

In other example embodiments, the second transmit/receive system includes a processor that processes at least one of commands and data from the second coil assembly and from an external system for transmission to the first coil assembly and processes data received from the first coil assembly for delivery to the at least one of the external system and the second coil assembly. In an example embodiment, the second coil assembly further comprises a digital interface, and the processor provides measurements related to the first signal, the second signal, and the charging signal to the digital interface. The measurement includes at least one of signal strength, bit error rate, energy per bit to spectral noise density ratio, frequency, and amplitude and phase shift at the first and second antenna structures of the first and second coil assemblies. In an example embodiment, the external system may include an external processor. In such embodiments, the measurement results are delivered to an external processor via a digital interface for at least one of alignment detection and closed loop charging system management and control. The external processor may provide the processor with near real-time voltage and current measurements on the second coil assembly, thermal measurements of the second coil assembly, Z-gap changes, fault alarms for the first coil assembly or the second coil assembly, alarms for intermediate charging performance events, and additional sensed data associated with the second coil assembly for transmission.

In other example embodiments, the first signal and the second signal are configured as narrowband signals or wideband signals depending on the stage of the charging cycle or whether a threshold of signal quality has been crossed.

In other example embodiments, the first signal and the second signal are configured as asynchronous spread spectrum signals. In such an embodiment, the first and second transmission/reception systems may each include a direct sequence spread spectrum system that transmits a complementary code sequence that enables the first and second transmission/reception systems to distinguish between signals and co-channel interference.

In an example embodiment, the hardware, software, and/or firmware is adapted to modulate the output signal using at least two of amplitude modulation, phase modulation, frequency modulation, orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques. The spreading technique may include at least one of direct sequence spreading, chirp spreading (CSS), binary quadrature keying (BOK), and frequency hopping.

In other example embodiments, the first and second transmit/receive systems each include a receiver, an analog-to-digital converter, a digital processor, a digital-to-analog converter, and a transmitter, the digital processor processing data from at least one of the first coil assembly and the external system for transmission to the second coil assembly and processing data received from the second coil assembly for delivery to at least one of the first coil assembly and the external system for processing. In an example embodiment, the analog-to-digital converter and the digital-to-analog converter are implemented as discrete integrated circuits and the digital processor is implemented as a field programmable gate array. Further, the analog-to-digital converter, digital processor, and digital-to-analog converter may be implemented as firmware residing in an Application Specific Integrated Circuit (ASIC). In an example embodiment, the digital processor of each transmit/receive system processes input data for transmission and processes data received from other transmit/receive systems using a software structure implemented on the digital processor. The first and second transmission/reception systems may optionally include at least one bandpass filter.

According to a second aspect, there is provided a method of charging a vehicle, the method comprising positioning a vehicle component relative to a ground component so as to receive a charging signal, the vehicle component comprising one or more charging coils, wherein each charging coil has a first full duplex inductively coupled data communications system comprising a first transmit/receive system that receives a first signal over a first inductive link and transmits a second signal over a second inductive link, and the ground component comprises one or more charging coils, wherein each charging coil has a second full duplex inductively coupled data communications system comprising a second transmit/receive system that transmits the first signal over the first inductive link and receives the second signal over the second inductive link. The ground assembly and the charging coil of the vehicle assembly are selectively activated for charging based on the geometric positioning of the vehicle assembly relative to the ground assembly. At least one of the first transmission/reception system and the second transmission/reception system is selected to have the same type of hardware, software, and/or firmware adapted to modulate an output signal and demodulate an input signal in the same manner as the other of the first transmission/reception system and the second transmission/reception system. During charging, charging management and control data is transferred between the first and second transmission/reception systems through the first and second inductive links.

In an example embodiment, the first and second transmission/reception systems are adapted to modulate the output signal using at least two of amplitude modulation, phase modulation, frequency modulation, orthogonal Frequency Division Multiplexing (OFDM), and spread spectrum techniques. The spreading technique may include at least one of direct sequence spreading, chirp spreading (CSS), binary quadrature keying (BOK), and frequency hopping.

In other example embodiments, at least one of software updates, diagnostic or telemetry information, and passenger entertainment service data is communicated between the ground component and the vehicle component during charging via the first inductive link and the second inductive link. The charging signal may be disabled when the ground component detects a fault event or receives a fault event from a vehicle component.

In other example embodiments, the first transmission/reception system processes at least one of commands and data from the vehicle component and the external system for transmission to the ground component, and processes data received from the ground component for delivery to the at least one of the external system and the vehicle component. The measurement results related to the first signal, the second signal and the charging signal may also be provided to the digital interface for processing. The measurement may include at least one of signal strength, energy per bit to spectral noise density ratio, frequency, and amplitude and phase shift at the first and second antenna structures of the vehicle component and the ground component. The measurement results may be delivered to an external processor via a digital interface for at least one of alignment detection and closed loop charging system management and control.

In still other example embodiments, the method includes transmitting at least one of near real-time voltage and current measurements on the vehicle component, thermal measurements of the vehicle component, Z-gap changes due to loading or unloading of a vehicle containing the vehicle component, a fault alert of the ground component or the vehicle component, an alert regarding an intermediate charging performance event, and additional sensed data related to the vehicle component from the vehicle component to the ground component.

In yet further example embodiments, the method includes configuring the first signal and the second signal as narrowband signals or wideband signals depending on a stage of a charging cycle or whether a threshold of signal quality has been crossed.

In yet further example embodiments, the method includes configuring the first signal and the second signal as asynchronous spread spectrum signals. The complementary code sequence may be transmitted between the first and second transmit/receive systems, the complementary code sequence enabling the first and second transmit/receive systems to distinguish between signals and co-channel interference.

According to a third aspect, there is provided a vehicle charging system comprising a clustered ground assembly comprising at least two independent coils, each coil having a first full duplex inductively coupled data communication system comprising a transmit/receive system that transmits a first signal over a first inductive link and receives a second signal from a vehicle over a second inductive link, the first and second signals being transferred between the clustered ground assembly and the vehicle during charging of the vehicle. The clustered floor assembly may comprise individual floor assemblies mounted in a close-continuous manner to form a single large floor assembly.

In an example embodiment, the vehicle being charged has two or more vehicle components mounted to allow higher power transfer than can be achieved with a single vehicle component, and the clustered ground component includes coils configured to match the geometry of the two or more vehicle components.

In further example embodiments, the charged vehicle may be equipped with clustered vehicle components in a geometry that matches clustered ground components. The cluster vehicle assembly may include at least two separate coils, each coil having a second full duplex inductively coupled data communication system including a transmit/receive system that transmits a second signal over the second inductive link and receives a first signal from the cluster ground assembly over the first inductive link, the first signal and the second signal being communicated between the cluster ground assembly and the cluster vehicle assembly during vehicle charging.

The clustered vehicle assembly and clustered ground assembly may each include two or more functionally identical assemblies, each functionally identical assembly including a magnetic induction antenna and a common resonant induction coil unit.

Drawings

The foregoing and other advantageous features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings in which:

fig. 1 shows a conceptual representation of an exemplary embodiment of a ground-side transmission device and a vehicle-side transmission device.

Fig. 2 illustrates an example embodiment of a full duplex radio frequency data link.

Fig. 3 shows a low harmonic waveform employed by the example embodiment of fig. 2 to avoid self-interference.

Fig. 4 shows a representation of digital amplitude shift modulation used by the example embodiment of fig. 2.

Fig. 5 illustrates an embodiment of a low harmonic generation circuit that produces the waveforms shown in fig. 3.

Fig. 6 shows a representation of digital amplitude shift modulation used by the embodiment of fig. 2.

Fig. 7 shows an embodiment of a receiver level detection circuit.

Fig. 8 shows an embodiment of an apparatus for self-interference cancellation.

Fig. 9 illustrates an embodiment of dynamic charging using the communication methods described herein.

Fig. 10 illustrates an example of a cluster deployment of transmitting devices in an example embodiment.

Fig. 11a illustrates signal transmissions and components used by an Inductively Coupled Communication System (ICCS) of a Wireless Power Transfer (WPT) system in an example embodiment.

Fig. 11b shows an example of a diversity receiver antenna for an Inductively Coupled Communication System (ICCS) of a Wireless Power Transfer (WPT) system.

Fig. 12a shows the functional elements of ICCS in an example embodiment.

FIG. 12b illustrates an example hardware implementation including a vehicle side assembly and a ground side assembly ICCS.

Fig. 13a shows a top view of a parking lot based wireless charging station deployed in a single row geographic arrangement in an example embodiment.

Fig. 13b shows a top view of a parking lot based wireless charging station deployed in a double row geographic arrangement in an example embodiment.

Fig. 14 shows an example of an expressway that can be used for dynamic charging in an example embodiment.

Detailed Description

Example embodiments for charging an electric vehicle will be described with reference to fig. 1-14, but those skilled in the art will appreciate that the teachings provided herein may be used with other non-vehicle resonant magnetic induction wireless power transfer systems. Such embodiments are intended to be within the scope of the present disclosure.

Fig. 1 shows a conceptual representation of an example embodiment, in which two apparatuses are provided, a ground-side apparatus associated with a ground-side wireless power transmitting device and a vehicle-side apparatus associated with a vehicle-side wireless power receiving device. The data link shown in fig. 1 may be implemented, for example, in the coil alignment error detection apparatus described in U.S. patent No. 10,193,400. As shown in fig. 1, the ground side device includes a frequency multiplier 10, a data modulator 20 that receives input data for transmission, and a synchronous detector 30 that receives data from the vehicle side device on a return link and provides output data. Similarly, the vehicle-side devices include a frequency multiplier 40, a homodyne detector 50 that receives data from the ground-side devices on the forward link, and a modulator 60 that sends data to the ground-side devices on the return link. The loop antennas 70 and 70 'of the ground side device communicate wirelessly with loop antennas 80 and 80' on the vehicle side device by induction in a conventional manner. A crystal-controlled reference oscillator 90 located in the ground-side device provides a common basis for coherent generation of all the radio frequency signals required for transmission and detection. Since this is a full duplex communication device, there are two separate transmit-receive links, a forward link from the ground side device to the vehicle side device and a return link from the vehicle side device to the ground side device. The vehicle-side loop antennas 80 and 80' are generally located below the bottom of the vehicle's conductive car body and are parallel with respect to the ground-side loop antennas 70 and 70 '.

The system and method described herein and shown in fig. 1 differs from conventional radio data communications as follows:

The communication path is full duplex and bi-directional, with a forward path from the ground side device to the vehicle side device, and a second return data path starting from the vehicle side device to the ground side device to transmit data.

The electronic communication mechanism is a near field magnetic field coupling between the two antennas 70, 80 and 70', 80' that is sensitive to the impinging magnetic field energy, rather than the far field free space propagation of conventionally practiced radio frequency data communications.

The forward path signal carrier provides the basis for generating the secondary path signal by means of frequency doubling. This means that the secondary path signal is harmonically related to the forward path signal and the technical difficulties of deriving a synchronization and coherent reference signal for return path synchronization detection are avoided. Furthermore, the coherent, harmonically related forward path signals, return path signals make it possible to suppress co-channel and off-channel interference as well as to suppress data link signals originating from otherwise identical devices in adjacent parking spaces simply and explicitly.

In the exemplary embodiment shown in fig. 2, the forward path frequency from the reference oscillator 90 is 13.560MHz. The return path operates at the third harmonic 40.680MHz of the forward path. Both frequencies are internationally allocated for non-communication industrial, scientific and medical (ISM) use. Communication usage is also allowed in ISM channels with reduced regulatory requirements, but interference is accepted from all other ISM channel users. The non-radiative near-field nature of the coherent transponder system described herein, and the waveguide below the cut-off structure comprised by the vehicle conducting underbody and ground surface in typical applications, makes the described system very tolerant of co-channel interference and for this reason very suitable for ISM-specified frequencies.

The forward path signal generation begins with a reference quartz crystal oscillator 90 operating at a frequency of 13.560 MHz. The signal is applied to a waveform generation stage that includes a third harmonic cancellation circuit 22 and an amplitude shifting modulator 24 that together comprise modulator 20 of fig. 1. Of course, other types of modulators may be used, such as frequency shift modulators, QPSK modulators, etc. In an exemplary embodiment, amplitude shift modulator 24 generates a rectangular waveform as shown in fig. 3, where T is the waveform period and the third harmonic power is approximately zero. The small loop antenna 70 with balanced feed functions as a forward path transmit antenna while the second vehicle-mounted balanced feed small loop antenna 80 functions as a forward path receive antenna. Both antennas 70, 80 are much smaller than the wavelength at the operating frequency and for this reason are poor free space radiators. However, when in physical close proximity, the two small loop antennas 70, 80 have significant mutual magnetic field coupling, which enables both the forward and reverse communication paths without significant free space propagation.

According to "ENGINEERING MATHEMATICS Handbook", third edition, tuma, jan j., mcGraw-Hill 1987 ISBN 0-07-065443-3, the fourier series coefficients of the modified sinusoidal waveform shown in fig. 3 are given by:

Of the first twenty fourier series coefficients, all coefficients except the six fourier series coefficients are zero. For the desired n=1 component, the non-zero coefficients are 5 th and 7 th suppressed-14 dB and-16.9 dB, 11 th and 13 th suppressed-20.8 dB and-22.3 dB, and 17 th and 19 th suppressed-22.9 dB and-25.5 dB. Although mathematically ideal waveforms have infinite third harmonic suppression, practical implementations will have less than infinite harmonic cancellation due to unequal 0-1 and 1-0 logic propagation delays and asymmetry from other small waveforms. Even so, the waveform of fig. 3 generated by the 3 rd harmonic cancellation circuit 22 with the circuit of fig. 5 has excellent third harmonic rejection (3 rd harmonic energy approaching zero), a very desirable feature to avoid self-interference between the third harmonic of the forward transmission path and the detection of the 40.680MHz return path. Conventional harmonic filtering techniques can be used to further suppress the remaining residual third harmonic energy if desired.

The low third harmonic generation circuit shown in fig. 5 comprises a step ring counter consisting of three D flip-flops 102, 104, 106, the three D flip-flops 102, 104, 106 being clocked at six times the required output frequency derived by PLL frequency multiplier 108 from the 13.560MHz frequency from reference oscillator 90. A pair of NAND gates 110, 112 decodes the step ring counter to produce the required rectangular wave that drives the forward link loop antenna 70 by means of two transistors 114, 116 arranged in a symmetrical push-pull configuration. The inductance of the two radio frequency chokes 118, 120 connected to the voltage source 122, in combination with the inductance of the loop antenna 70 and the antenna resonant capacitor 124 shown in fig. 5, constitute a resonant circuit that provides suppression of residual harmonic energy, particularly the third harmonic in the illustrated embodiment.

As shown in fig. 2, in an exemplary embodiment, amplitude Shift Keying (ASK) modulation is applied to the forward link carrier by amplitude shift modulator 24 by varying the value of the forward link transmit stage supply voltage. The logic one bit is encoded as a full signal amplitude, with the transmit stage operating from a full supply voltage. The logic zero is encoded as half the full signal amplitude with the transmit stage operating at a reduced supply voltage. Varying the transmitter stage supply voltage in this manner produces the transmit waveforms shown in fig. 4.

On the vehicle side of the forward link, the variable gain control amplifier 52 increases the received signal amplitude from the loop antenna 80. Since the received signal has a non-zero value even for a logical zero, there is always a 13.56MHz carrier (see fig. 4). A portion of the amplified received signal is applied to a limiting amplifier 54, which limiting amplifier 54 removes received signal amplitude variations introduced by amplitude data modulation and due to occasional variations in the magnetic field coupling between the two forward path loop antennas 70, 80. The output of limiting amplifier 54 is a constant amplitude square wave that indicates the instantaneous polarity of the received signal. The portion of the variable gain amplifier output that is not applied to the limiting amplifier 54 is applied to one input of a multiplying mixer 56. The output of limiting amplifier 54 drives the other mixer input. The limiting amplifier 54 and mixer 56 comprise a homodyne detector 50 in which the input signal carrier is extracted and used for synchronous detection of the input signal. The propagation delay of the limiting amplifier 54 may be ignored or compensated for to achieve all of the advantages of coherent detection. The output of homodyne detector 50 is equivalent to full wave rectification of the input amplitude modulated signal. The resistor-capacitor low pass filtering removes the double carrier frequency ripple, leaving a dc voltage that varies in amplitude according to the applied serial digital modulation. The carrier ripple filtered post homodyne detector signal is applied to a level detection circuit 59, which level detection circuit 59 feeds an Automatic Gain Control (AGC) control loop 58 and also extracts forward path serial data by means of amplitude level detection. The implementation thereof will be described in more detail below with reference to fig. 7.

The forward path carrier recovered by limiting amplifier 54 is applied to tripler 42, implemented as a pulse generator, with tripler 42 followed by a filter or equivalently a phase locked loop after first passing through crystal filter 44, which disables the frequency multiplier operation except in the presence of a sufficiently strong forward link signal to avoid conflicting frequencies. The resulting 40.680MHz carrier is applied to a second amplitude shifting modulator 62 using 100% and 50% modulation levels as previously described to encode the serial digital data on the return data path. Except that elements 102-112 of fig. 5 are not required, return path amplitude shift modulator 62 drives small resonant loop antenna 80' as previously described.

On the ground side of the return link there is an amplifier 32 controlled by an Automatic Gain Control (AGC) circuit 34 and a small resonant loop receiving antenna 70'. Synchronous detection of the received return path signal is achieved by generating 40.680MHz synchronous detection reference signals by means of frequency triples. Although the frequency error of the synchronous detection reference signal is guaranteed to be zero by the overall design of the device, the zero phase error cannot be guaranteed and obtained by phase-locked loop control using quadrature channel phase detection and phase shifter stages. Placing the phase shift stage (phase shifter 12) before tripler 14 instead of after tripler 14 means that the total phase shift control range only needs to exceed 120 degrees instead of the full 360 degrees needed by synchronous detector 30 to ensure phase synchronous detection. To facilitate quadrature reference signal generation at 40.680MHz, the ground side 13.560MHz signal from crystal oscillator 90 is multiplied by tripler 14, which outputs two square waves offset by 90 °. The tripler 14 is implemented as a 6-fold phase-locked loop multiplier followed by a quadrature divide by two (dwo) circuit, as shown in fig. 6, that includes D flip-flops 130, 132 to obtain the I and Q synchronization detection reference signals. It will be appreciated that when the Q channel signal output at 17 is equal to 0V, then there is no phase difference. However, if the output at 17 is not 0V, there is a phase difference and the phase locked loop of the phase shifter 12 operates to drive the phase difference to zero.

The variable phase shift circuit 12 is implemented as a series of capacitively loaded logic inverters with variable supply voltages. Capacitive loading increases the propagation delay from the inverter input to the inverter output. The increased supply voltage reduces inverter propagation delay, thereby reducing inverter phase shift. The conventional phase-locked loop, consisting of Q-channel mixer 17 and associated loop filter 16, drives the Q-channel output of sync detector 30 to zero, thereby ensuring proper phase synchronization for I-channel amplitude detection.

An I-channel mixer 38 of synchronous detector 36 mixes the output of amplifier 32 with the I-channel output of tripler 14 to provide an input signal to level detection circuit 36. The forward path level detection circuit 59 on the vehicle side is identical to the return path level detection circuit 36 on the ground side, except that the former includes a carrier detection function and an associated voltage comparator 138 (fig. 7) that detects the presence of a return path signal.

Fig. 7 shows an embodiment of the receiver level detection circuit 36. The peak hold capacitor 134, driven by the full wave precision rectifier 136, maintains a maximum detected voltage level, which in turn is maintained at a constant value by the AGC circuit 34 (fig. 2). The peak detect voltage with stable AGC amplitude provides a reference voltage for the 1-0 serial binary detect voltage comparator 138 and a reference voltage for the carrier detect voltage comparator 140 by means of the R-2R-R resistor divider 142, which R-2R-R resistor divider 142 sets the voltage comparator reference voltages to 25% and 75% of the peak of the post detect waveform shown in fig. 4, respectively. The carrier sense voltage comparator 140 provides a quick indication of the occurrence of a vehicle side fault. If a fault, such as a sudden unexpected unloading, occurs on the vehicle side, the return link carrier is immediately disabled. The ground-side apparatus detects carrier removal delayed by only the pre-detection filter delay and the post-detection filter delay, and immediately stops wireless power transmission. The full value of the peak hold function is applied to AGC integrator 144, and AGC integrator 144 adjusts the gain of AGC amplifier 34 and, thus, the gain of amplifier 32 to maintain peak hold capacitor 134 voltage equal to AGC set point 146 voltage. The conventional precision rectifier 136 generates an output voltage proportional to the absolute value of the input voltage and is comprised of one or more small signal diodes placed in the operational amplifier feedback path, which configuration effectively eliminates diode forward voltage drops, enabling precision rectification of low level signals with minimal error.

Alternatively, return link synchronization detection may be performed by using an I detection channel and a Q detection channel that are coherent but not phase synchronized. Amplitude and phase modulation can be extracted in a conventional manner, where amplitude is the root mean square of the I and Q channels and phase angle is the arctangent of the ratio of I and Q. In this alternative embodiment, no phase shift and phase lock circuitry is required.

Fig. 1 and 2 show four loop antennas, a transmit and receive antenna pair 70, 80 for the forward link and a second pair of antennas 70', 80' for the return link. In alternative embodiments, the forward link antenna pair and the return link antenna pair may be combined into a single loop antenna with a conventional antenna duplexer to separate and isolate the forward link signal and the return link signal. Also, one data link signal or two data link signals may be multiplexed onto a wireless power transfer coil or auxiliary electromagnetic structure, such as an eddy current generation coil as part of the coil alignment error detection apparatus described in U.S. patent No. 10,193,400.

For reasons of simplicity and reduced cost, it is desirable that the forward path and the reverse path share a common antenna structure. The problem is then the combination and subsequent separation of the forward and reverse path signals from each other and from other electrical signals encountered by combining the functions into a single antenna structure. In general, there are two general ways to achieve signal combining, splitting and routing. The first approach uses hybrid transformers, hybrid couplers or directional couplers that distinguish forward path signals from reverse path signals by means of signal flow direction. The second approach relies on a frequency selective filter that distinguishes between signals based on frequency. The frequency selective multiplexer may be implemented with LC lumped components, distributed components or as a monolithic circuit comprising a plurality of resonant elements and coupling elements. The frequency multiplexing block may combine both signal direction and signal frequency discrimination.

As shown in fig. 8, the performance of the signal multiplexer functional block (circuit) can be enhanced by adding electrical signal cancellation. An electrical signal cancellation function (circuit) is placed in the path between the common forward/reverse path antenna and the receiver. The common antenna is connected to port 202 of signal splitter 204. One splitter output reaches the input port of mixer 206 by means of isolation amplifier 208. Samples of the signal to be cancelled are applied to port 210 and the applied signal is phase shifted by variable phase shifter 212 and applied to the local oscillator port of mixer 206 by means of limiting amplifier 214. The output of mixer 206 is applied to loop filter 216 and then to the control port of variable phase shifter 212. Components 212, 214, 206, and 216 form a phase control loop that ensures that the cancellation signal is 90 degrees out of phase with the unwanted signal components applied to port 202. The zero phase error corresponds to a zero dc voltage at the output of the mixer 206.

As shown in fig. 8, the second output of the splitter 204 reaches the combiner 218 by means of an isolation amplifier 220. As shown, signal combiner 218, splitter 222, isolation amplifier 224, mixer 226, loop filter 228, and attenuator 230 together form an amplitude control loop. A portion of the quadrature sampled signal output by phase shifter 212 is applied to a fixed 90 degree phase shifter 232, producing a 180 degree out of phase version of the cancellation signal, which 180 degree out of phase version of the cancellation signal passes through controlled attenuator 230 and into signal combiner 218, where complete cancellation of the unwanted signal is accomplished if the cancellation signal amplitude is correct. A portion of the combiner 218 output signal is directed via splitter 222 to a receiver input at 234. The other portion is directed through an isolation amplifier 224 to a signal port of a mixer 226, the mixer 226 acting as a coherent amplitude detector driven by the unattenuated portion of the 180 degree out of phase cancellation signal. The output of mixer 226 is passed through loop filter 228 which controls variable attenuator 230. Those skilled in the art will appreciate that the zero cancellation signal amplitude error corresponds to a zero dc voltage at the output of the mixer 226.

In operation, when a vehicle approaches a wireless charging station, communication is established prior to the start of charging. Once charging begins, full duplex communication is used to regulate and control aspects of wireless power transfer operation, including transmitted power levels, output voltages and currents, and to monitor proper system operation. To establish control communications, the surface device may continuously or periodically transmit a forward path signal while listening for a vehicle-generated return path signal. Duplex communication is initiated upon detection of a vehicle-generated return path signal. Alternatively, the vehicle-side electronics may make initial contact with a return path signal that is temporarily derived from a temporary crystal oscillator (not shown) and that is incoherently detected by the ground-side electronics, rather than with a commonly used carrier wave that is recovered by homodyne detector 50. When the ground side receives the vehicle signal, the ground side device transmits a forward path signal. In the event of a vehicle-side communication initiation, the vehicle-side device disables the temporary crystal oscillator and resumes coherent transponder operation upon successful homodyne detection and carrier recovery.

Both of the above-described activation methods rely on the transmission of either a forward path signal or a return path signal. Communication may also be advantageously initiated without forward path transmission or reverse path transmission. In an exemplary embodiment, the ground device detects a change in the impedance of the wireless power transfer coil caused by the air vehicle and responds by transmitting a forward path signal. This embodiment reduces or eliminates unnecessary signal emissions and may be advantageous in some management environments. In addition to the wireless power transfer coil, an initial impedance change may be detected in the coil alignment auxiliary coil or the near field communication antenna. In addition to impedance variations, variations in the transimpedance between the isolated electromagnetic elements can also be used to initiate communication.

In the exemplary embodiment described herein, the 40.680MHz reverse signal is a simple integer multiple of the 13.560MHz forward signal frequency, where both signals fall within the existing internationally specified ISM-industrial scientific medical-frequency allocations. Other frequencies and frequency pairs having non-integer frequency ratios may also be used. For example, two international ISM bands with center frequencies of 2450MHz and 5800MHz may also be used. The coherent repeater architecture described herein, in conjunction with conventional phase-locked loop techniques, can generate a 5800MHz signal that is frequency synchronized with a 2450MHz signal having a frequency ratio M/N of 116/49, where m=5800 MHz and n=2450 MHz. Other combinations of ISM band frequencies and non-ISM band frequencies, frequency pairs with other integer or rational fraction frequencies, and multiple simultaneous transmit and receive carrier frequencies are also possible. For example, multiple return path data channels may also be used, each transmitting data at a different multiple of M/N of the transmission frequency of the first inductive link, where M and N are integers. Terrestrial devices and remote devices linked by far field propagation (as opposed to near field propagation) may also use full duplex frequency coherent communications.

Dynamic charging

Dynamic electric vehicle charging is a special case of providing electric power to an electric vehicle while the electric vehicle is in motion. As shown in fig. 9, the use of dynamic charging may be achieved using resonant magnetic induction, wherein a plurality of independent transmitters 300 are mounted in a linear array in the roadway and energized in a controlled sequence as the target vehicles 310, 312 travel over the linear array 300. Dynamic charging may be achieved when only one vehicle 310 is moving across the array of transmitters 300, or in a more realistic case, when there are multiple electric vehicles 310, 312 of different types, speeds and power requirements moving across the array of transmitters 300. In the latter case, the actuation sequence of a particular transmitter 300 will be variable within the array and will depend on various vehicle types and their movements, inherently unpredictable factors. Thus, the technical requirements of dynamic charging present special technical challenges. The above system solves a number of problems with dynamic charging as listed below.

The most serious problem with dynamic charging is the need for vehicle-to-ground and ground-to-vehicle communications, where discrete high-speed, highly differentiated and reliable data is transmitted as a requirement to command and control the charging system. This data is needed to operate the charging system in the case of one or more vehicles that can pass through a series array of inductive power transmitters embedded in the ground.

As shown in fig. 9, an array of inductive power transmitters 300 is mounted under the roadway, with each transmitter 300 being placed in a series array along the longitudinal axis of the roadway. The intention is to provide a section of road on which electric energy can be supplied to vehicles 310, 312 travelling on a linear array of induction transmitters 300 when driven by electric vehicles 310, 312. It is desirable to power only the transmitter 300 directly below the vehicle receiver. The transmitter 300 without a vehicle above should remain inactive (i.e., not powered on).

In each instance of inductive power transfer, communication between a vehicle-based receiver and a ground-based transmitter occurs, whether in the dynamic charging mode described herein or in the simpler case of static charging described above, where a vehicle equipped with a single power receiver is parked above a single power transmitter embedded in the road surface and remains stationary. This is desirable for vehicle identification, billing for energy purchase, regulation of current and voltage, resonant frequency, vertical gap separation distance, primary to secondary alignment, and other purposes such as safe operation and emergency power down. This is also true in the case of a moving vehicle that is charged while in motion, except that a single transmitter built into the vehicle communicates with multiple independent transmitters in sequence. This one-to-one relationship of movements imposes very significant communication challenges.

The method of operation for charging a moving vehicle is to energize each individual transmitter 300 in a linear array to create resonant magnetic fields in a sequential pattern as the vehicle receiver 320 passes each individual transmitter 300. The type of vehicle, its specific charging requirements, its speed, alignment with respect to the transmitter 300, and its predicted trajectory are all important factors that make this problem difficult to solve.

As depicted in fig. 9, the determination is that an array of pavement-embedded transmitters 300 will experience the presence of two or more vehicles 310, 312 simultaneously and in response to a variable condition for each vehicle 310, 312. In this case, the communication between each vehicle 310, 312 and the particular surface transmitter 300 over which each vehicle 310, 312 is positioned is discrete and distinct such that no other vehicle 310, 312 is confused or data transmissions from nearby vehicles 310, 312 are received and misread. The requirements for this include the data communication system being proximally constrained to the target area of the intended vehicle 310, 312. By comparison, broadcast radios and other systems such as Wi-Fi have a range that can be easily received by many nearby vehicles.

The first requirement is to have a transmit-receive capability limited to a height of less than 2 meters. (a vehicle moving at 60MPH travels 88 feet per second. The time the receiver is exposed to the transmitter may be about 0.02 seconds. In this time frame, a time delay of 0.04 seconds to 0.07 seconds in typical signaling of digital communication systems is clearly not sustainable.

The second requirement is that there is no or very low time delay (or time delay) in the signal. This is desirable because the vehicles 310, 312 can move at a high rate on multiple transmitters 300 and discrete communication between the in-vehicle receiver 320 and any one transmitter 300 should be ensured.

A third requirement is that the communication system be able to "hand over" or order communications to the ordered array of transmitters 300. This may be achieved by wiring the transmitters 300 to each other or by enabling one transmitter 300 to communicate using the near field communication system described herein to address adjacent transmitters 300 in the ordered array.

The fourth requirement is full duplex operation or bi-directionality to ensure that data can be exchanged in both directions-from vehicle to ground and from ground to vehicle-within a very short time span in which the vehicles 310, 312 are present on the transmitter 300.

A fifth requirement is to allow uninterrupted communication under all weather and environmental conditions. This is accomplished through the use of magnetic energy, which, as described herein, allows communication through bodies of water, snow, ice, and other harsh road surface conditions.

The sixth requirement is to avoid the problem of multiple antennas remote from the vehicles 310, 312. Multiple remote antennas introduce significant problems, such as multipath signal nulling, due to road and body disturbances. High reliability vehicle identification with multiple antennas is difficult to ensure that malicious hacking or other network malicious behavior is avoided.

Those skilled in the art will appreciate that the communication system described herein provides a unified solution for each of these requirements.

As described above, dynamic charging allows the mobile vehicle to be charged while traveling as the vehicles 310, 312 pass by the transmitters 300 in the road. Each transmitter 300 is energized in a controlled sequence as each transmitter 300 anticipates the presence of a vehicle 310, 312 thereabove. Since the vehicle receiver 320 is "present" only a short time above any one charging station, a sequencing system is needed that knows where the vehicle receiver and the charging station's transmitter are related to each other in real time. Ideally, the pre-sequenced ignition process effectively establishes a traveling magnetic energy wave that moves at the same rate as the vehicle receiver 320. To do this, a communication system having minimal latency is needed, such as the system described herein. As described above, the communication system described herein is very fast (near zero latency) and very close so that the position of the receiver 320 relative to the transmitter 300 is known. Thus, to achieve dynamic charging, a series of charging stations equipped with the communication system described herein are provided. During operation, each charging station and/or vehicle transmitter provides information to the next transmitter including, for example, vehicle identification, billing for energy purchase, regulating current and voltage, resonant frequency, vertical gap separation distance, primary to secondary alignment, and for other purposes such as safe operation and emergency power down, location, timing, trajectory, and/or speed information about the vehicles 310, 312 such that the next transmitter fires when the wireless charging receiver 320 of the vehicle is positioned over the transmitter 300 during travel.

Robust hybrid alternative implementation

For Wireless Power Transfer (WPT) systems of the type described herein, there is also a need for a secure, well-defined point-to-point low latency full duplex link between the ground-side charging system and the vehicle-side charging electronics. The communication link needs to support Battery Management System (BMS) commands and other communication scenarios between the ground electronics and the vehicle electronics.

The supported operating scenarios include static and dynamic charging under various weather conditions in the domestic and international markets. An Inductively Coupled Communication System (ICCS) is reliable in a congested radio environment with licensed and unlicensed co-channel users while causing minimal interference. The same inductive communication system is also designed to operate with water, snow and ice.

In one embodiment, a narrowband full duplex, low latency, near field data link for controlling a resonant inductive wireless power transfer system is enhanced or replaced by a wideband full duplex, low latency, near field data link between a ground side component (GA) and a vehicle side component (VA). Such improved (hybrid or broadband) wireless duplex data links allow for greater security, higher data rates, dynamic bandwidth selection, frequency agility, and modulation schemes agility to meet local spectrum regulations, electric and Magnetic Field (EMF) security, and data rate requirements for use in near field inductively coupled communication systems.

To support the broadest possible static deployment configuration, the data link should be able to tolerate interference generated by adjacent or proximate ground-side component placement. The adjacent installation is weakened either in distance (geographically or vertically in the case of a parking garage) or by a shielding structure (e.g. by a curb or floor in the parking garage). The adjacent system may be located in the next vehicle parking space or lane. In some proximity cases, multiple clustered ground components may be deployed in the same parking space or lane service vehicle equipped with corresponding clustered vehicle components in a matching geometry. Adjacent deployments in which a "macro" GA is made up of multiple smaller clusters GA are possible.

In a dynamic charging deployment configuration, such as in a GA-equipped driving lane, the data link should be tolerant of interference generated by adjacent or proximate ground-side component placements, as well as support soft handoff capability between consecutive ground-side components or clusters of ground-side components. In soft handoff, as the vehicle moves in the GA-equipped travel lane, the charging platform of the vehicle will in turn support multiple data links to successive ground components.

Cluster charger scheme

The modular coil design is advantageous in customizing WPT systems to meet user needs, where a single coil assembly may be deployed as a stand-alone Ground Assembly (GA), and where two or more coil assemblies may be clustered to achieve a larger (geometrically) ground assembly capable of higher power transfer. For example, in the case of buses, trucks, trains, construction equipment or any other vehicle requiring wireless power transfer, it is desirable to locate the ground side components and corresponding vehicle side components (VA) of a cluster mounted in close proximity to each other (e.g., buses having VA consisting of 4 adjacently mounted 50kW charging coils, each with its own duplex inductive communication), and it is desirable to mitigate interference of the communication signals of one coil with the communication signals of an adjacent coil.

With this deployment flexibility, a vehicle may have one, two, or more vehicle components that are mounted to allow higher power transfer than can be achieved with a single VA. Similarly, the ground components (GA) may be clustered together and selectively enabled to match the geometry of the VA plant. In such cluster deployments, where individual GAs are installed in a close succession to form individual macro GAs, the inherent advantages of near field data links in not interfering with other data links in the vicinity due to inherent radiated power reduction range limitations are impacted. For inductive communication links in the near field, the magnetic field strength and magnetic field power drop at rates of 1/(r ³) and 1/(r ⁶), respectively (where r=radius).

Although the far field radiated magnetic field from the antenna drops only at a magnetic field strength of 1/r and a magnetic field energy of 1/r ², the magnetic near field dominates for distances up to about λ/2π. For example, the radiation resistance of a magnetically inductive near field transmit antenna at 13.56MHz is very small compared to its reactive impedance (typically a ratio of less than 0.0005) because most of the energy is coupled in the near field. Thus, the energy propagated in the far field of the magnetic signal is negligible compared to the energy propagated by an equivalent intentional radiation system. The strong decrease in the field with distance means that, despite the care taken in processing the signals from adjacent coils of the same clustered coil assembly, there is no concern about interference between the coils of adjacent vehicles or charging stations.

FIG. 10 illustrates an example of cluster deployment in an example embodiment. In this case, a vehicle (e.g., bus) 1001 is equipped with a clustered vehicle assembly 1004 mounted to the underside of the vehicle 1001. As shown, passenger stations or parking spaces 1003 are also equipped with corresponding cluster deployed floor assemblies 1002.

Fig. 11a illustrates signal transmissions and components used by an Inductively Coupled Communication System (ICCS) 1101 of a Wireless Power Transfer (WPT) system in an example embodiment. Fig. 11a shows a cross section of ICCS, 1101, where a Vehicle Assembly (VA) 1102 and a Ground Assembly (GA) 1103 are shown vertically opposed. Other deployment options are possible, for example, horizontally mounting the VA 1102 on the side of the railcar with the GA 1103 mounted on the wall. Any orientation of GA to VA in the deployment can be made as long as a closely parallel opposed relationship between VA and GA can be achieved. The VA 1102 communication components include at least one pair of receive antennas 1104 and 1106 located at the periphery of a single transmit antenna 1105. VA receive antennas 1104 and 1106 receive transmissions 1110 and 1111 from GA transmit antenna 1108. Similarly, GA receive antennas 1107 and 1109 receive transmitted signals 1112 and 1113. Bi-directional charge signal 1114 or 1127 may occur at any time during the communication session.

Additional near field receiver antennas may be employed to aid in signal reception and to enhance the parallelism capability provided by the full duplex communication system.

Fig. 11b shows an exemplary electric vehicle 1115 from below. In one embodiment, additional receiver antennas may be provided on VA 1102 or within VA 1102. With at least two antennas on the x-axis (front to back) and at least two antennas on the y-axis (left to right), VA 1102 will be able to determine GA coil alignment displacement along the x-axis and y-axis. Preferably, these VA-mounted receiver antennas 1116, 1117, 1118, and 1119 will be placed at the four corners of VA 1102, within the range of signals 1112 and 1113 of magnetically coupled GA transmitter 1108. VA coil assembly 1126 for the transmission and reception of bi-directional charge signals 1114 and 1127 is also located in VA 1102 nominally located below transmit antenna 1105 of VA 1102. The GA (not shown) architecture replicates the communication antenna and charging coil assembly to mirror the communication antenna and charging coil assembly of VA 1102 to achieve duplex communication and bi-directional charging.

Note that the additional diversity receiver antennas may also be located anywhere on the vehicle, preferably shifted as far as possible along the length and width of the vehicle, forming secondary distributed antenna/receiver systems 1121, 1122, 1124, and 1125. Due to the distance of the GA-based transmitters from the distributed antennas 1121, 1122, 1124, and 1125, the receiver antennas may be magnetic induction loops or near field antennas, as indicated by the reactive near field range and the radiated near field (also referred to as fresnel zone) range of signals 1112 and 1113 of the GA transmitter 1108. In some embodiments, the shifted diversity receive antennas may be magnetically coupled by loop antennas mounted coplanar, parallel or orthogonal (to the transmitter loop antennas) depending on the distance from the magnetic transmit antenna(s). In cases where the transmitter-to-antenna range or co-planar mounting capability is not determined, a hybrid loop antenna with one loop element parallel to the transmitter loop and a second loop element disposed orthogonally can also be used to extend the magnetic coupling link.

In the case of dynamic charging, the distributed forward antennas 1121 and 1122 allow for an increased communication range, enabling communication with the current GA in the forward direction of the GA. Such advanced communication enables the GA to be in the path of the vehicle power-up time before it is necessary to minimize the ramp-up. The distributed lateral antennas right 1122 and 1124 and left 1121 and 1125 also provide center alignment in the direction of travel to maximize coil efficiency.

In one physical embodiment, four or more receiver antennas 1116, 1117, 1118, and 1119 are distributed across VA 1102 in a back-and-forth (relative to the forward direction of travel) manner and in a right and left lateral manner. Four additional antennas 1121, 1122, 1124, and 1125 are added, 2 of which are attached to the front 1120 (e.g., in the bumper, under the bumper, or on the frame), and 2 of which are similarly attached or embedded on the rear 1123. In a front-to-back deployment, the antenna should have the largest possible spacing to the left and right on the horizontal axis.

The distributed antenna may be backhaul to ICCS 1101 using a wired or wireless (e.g., bluetooth, zigbee (IEEE 802.15)) connection. ICCS 1101 will compensate for the different reception and processing times required for the communication link method and data protocol used.

Distributed antennas 1121, 1122, 1124, and 1125 having a common or known offset from the horizontal plane can also achieve improved alignment capabilities. Positioning and ranging techniques, such as Signal Strength Measurements (SSM), time of arrival (TOA), and time difference of arrival (TDOA), are becoming available with diversity receivers. Angle of arrival (AoA) techniques will be implemented using directional receiver antennas. Vehicle front directional antennas with AoA technology are particularly advantageous for positioning and alignment in the forward direction.

Permanent 79GHz band allocation for Intelligent Transport Systems (ITS) facilitates hybrid positioning using TOA, TDOA, AOA or using two or more of the described techniques. The 12 ITU (international telecommunications union) defined industrial, scientific and medical (ISM) bands are another potential spectrum for alignment (6 are globally available, the other 6 ISM bands may be available according to local regulations). Alignment accuracy will vary with the use of higher frequencies that provide greater resolution and lower frequencies that provide lower resolution.

The use of distributed antennas with TDOA, AOA or TDOA-aOA hybrid positioning techniques can be used for the generation of Z-axis (vertical) measurements. In some embodiments, a non-radio device, such as an ultrasonic transducer rangefinder, may be used for Z-axis estimation.

Alternatively, if the vehicle is not properly equipped, nominal Z-gaps for make, model, manufacturer, and variant may be uploaded from the vehicle or land-side networking server for setting the wireless power transfer GA voltage and coil enablement in the coil cluster.

Software defined radio

One option for achieving the improvement ICCS 1101 is to use a software defined transmitter and receiver to improve signal transmission between the ground station and the vehicle-mounted device using inductively coupled communication between the ground-side assembly (GA) 1103 and the vehicle-side assembly (VA) 1102.

In an example embodiment ICCS 1101 is designed to be selectable between two or more types of circuits for amplitude modulation, phase modulation and frequency modulation and circuits that enable the use of spreading techniques such as direct sequence spreading and chirp spreading (CSS) (e.g. binary quadrature keying (BOK), frequency hopping and Direct Modulation (DM)) as required. As described below, in example embodiments, such features may be implemented in a Field Programmable Gate Array (FPGA), although the described functions may also be deployed using discrete integrated circuit components and/or multi-chip modules and/or software executed by other processing devices such as a Digital Signal Processor (DSP). In some embodiments ICCS 1101 may use multiple simultaneous subcarriers as in an orthogonal frequency division multiplexing system (OFDM), where subcarriers may be allocated to unlicensed spectrum (or reserved spectrum) and any of the modulation schemes described are used.

Fig. 12a shows the functional elements of ICCS in an example embodiment. As shown, the receiver 1201 uses one or more antennas dedicated to magnetic induction signal transmission. As described above, the received analog signal may be filtered in the receiver 1201. The received signal is processed by a digitizing element 1202 to obtain a received analog signal and convert it to a digital representation of the signal. The digital representation of the received signal is then digitally processed by the processing element 1203. The data extracted from the processed signal is then output via digital interface 1206.

Input digital data may also be applied to the processing element 1203 via the input interface 1207. The input data is packetized by the processing element 1203 before being converted into an analog signal in the analog conversion element 1204. Once in analog form, the signals may be filtered and transmitted by the transmitter 1205 via one or more antennas dedicated to magnetic induction signal transmission.

In an example embodiment, the ICCS functional elements of fig. 12a may be implemented in any of a variety of ways. For example, ICCS may be configured to:

circuits including discrete Integrated Circuits (ICs) (e.g., analog-to-digital converters (ADCs), digital-to-analog converters (DACs)) having programmable elements (e.g., field Programmable Gate Arrays (FPGAs), EEPROMs, etc.);

hybrid hardware (IC), software, and embedded firmware in a multi-chip module;

Firmware residing in an Application Specific Integrated Circuit (ASIC) containing the required control logic, digitizing and analog conversion functions, and

Software architecture running on a computing platform, such as a Central Processing Unit (CPU) or Digital Signal Processor (DSP), with accompanying digital-to-analog and analog-to-digital circuits.

In each case, analog signal filtering may be included according to the requirements of the selected design (e.g., a superheterodyne design with a bandpass Intermediate Frequency (IF) stage or a direct conversion design with limited analog bandwidth).

The choice of which ICCS implementation (FPGA vs. DSP) and deployment (as a component of a discrete IC, multichip IC module, or ASIC) to use is highly dependent on development costs, throughput, and necessary computational resource costs. In an implementation, the FPGA provides parallel path signal processing, while the CPU/DSP provides excellent memory access and operating system to simplify tasks. Discrete IC packages offer maximum flexibility in selecting components and placing them, while multi-chip modules provide fixed interconnections between discrete components. ASIC packages are provided in ICCS components and interconnects into a single integrated subsystem at the highest development time and cost, but with the simplest deployment. In the example embodiment, ICCS configurations are selected at the time of manufacture, but may also be selected by the user during use.

Fig. 12b shows an example embodiment of ICCS 1101 including VA1202 and GA1201 in a discrete integrated circuit embodiment. As shown, for the short-range, low-power magnetic field link between GA 1260 and VA 1261, communication channels 1211 and 1227 use magnetic induction coupling with minimal propagating magnetic fields. GA communication signal 1211 and VA communication signal 1227 may be narrowband or wideband depending on pre-set programming, the stage of the charging cycle (proximity, coarse positioning, fine positioning, foreign Object Detection (FOD) and field object detection (LOD) scanning, charging termination), or whether a threshold of signal quality (e.g., received signal strength, bit error rate) has been crossed.

Core 1262 of GA inductively coupled communication system 1260 includes Field Programmable Gate Array (FPGA) 1265, analog-to-digital converter (ADC) 1263, and digital-to-analog converter (DAC) 1264.FPGA 1265 provides computing resources. The computational operations of FPGA 1265 include signal processing (e.g., signal summing, combining and selecting; modulation, demodulation, digital filtering, data extraction, automatic Gain Control (AGC), and ICCS hardware control). Data from the GA and external systems is input into GA core 1262 via digital interface 1240 for processing for transmission to VA 1261.

GA core digital-to-analog converter (DAC) 1264 is used to convert the digital output bit stream of the FPGA to a quantized analog signal, which is then amplified by transmit amplifier 1208 and then banded and smoothed by band pass filter 1209 and transmitted by GA transmit antenna 1210, which propagates as induced magnetic signal 1211.

The signal 1211 of the GA communication passes through an air gap 1266 between VA 1261 and GA 1260 and is then received at VA receiver antennas 1212 and 1213 (note that in this example, two receiver antennas are used, but the design supports the use of a single receiver antenna and any multiple receiver antennas). Once received by one or more of the VA pair-coupled antenna structures 1212 and 1213, the GA signal is bandpass filtered using filters 1214 and 1215. The band limited signal is then amplified by a pair of Low Noise Amplifiers (LNAs) 1216 and 1217, each of the Low Noise Amplifiers (LNAs) 1216 and 1217 being used for the VA receiver path. The second pair of bandpass filters 1218 and 1219 is then used to limit the signal frequency bandwidth for direct digital conversion on each of the VA receive paths.

Analog-to-digital conversion occurs at VA ADC 1223. VA ADC 1223 may be implemented as a paired set of ADCs or as an n-channel ADC (depending on the number of receive antennas used). The digitized signal is then passed to VA FPGA 1222.VA FPGA 1222 converts the received digitized signals using conventional digital signal processing techniques and then processes the reconstructed bit stream (e.g., removes framing, training sequences, implements forward error correction and data encoding (e.g., from encoding using convolutional encoding, turbo encoding, hamming codes), decodes the security masked bit sequence), and delivers the bit stream via digital interface 1238 to Vehicle Battery Management System (VBMS) 1239, potentially through an intermediate processor, network, and protocol such as a controller area network (CAN bus) (not shown). The measurement results associated with the communication signals are output to the vehicle-based processor 1250 over the digital interface 1236. The measurement results related to the charging signal are output on the digital interface 1237.

According to the configuration of VBMS and onboard systems, the Vehicle Battery Management System (VBMS) 1239, vehicle occupant information system, vehicle entertainment system, and other onboard data or telemetry systems provide bitstreams to VA FPGA 1222 via digital interfaces 1238 and 1243. VA FPGA 1222 applies framing, training sequences, implements forward error correction and data encoding (e.g., using convolutional encoding, hamming codes, hadamard codes), encodes the security masked bit sequence, and delivers the bit stream to VA digital-to-analog converter (DAC) 1221. The output of VA DAC 1221 is then amplified by transmit amplifier 1224. The VA signal for transmission is then filtered by a bandpass filter 1225 to match the desired channel bandwidth. The band limited analog VA signal is then transmitted over magnetic field air interface 1266 using coupled antenna structure 1226.

The induced magnetic signals 1227 of the VA are received by one or more of the coupled antenna structures 1228 and 1229 of the GA. The VA signal is then bandpass filtered on each GA receive path using filters 1230 and 1231. The band limited signals are then each amplified by a pair of Low Noise Amplifiers (LNAs) 1232 and 1233, each of the Low Noise Amplifiers (LNAs) 1232 and 1233 being used for the GA receiver path. The second pair of bandpass receivers 1234 and 1235 are then used to limit the signal frequency band for direct digital conversion on each of the GA receive paths. In some configurations of ICCS, band pass filters 1209, 1214, 1215, 1218, 1219, 1225, 1230, 1231, 1234 and 1235 may be constructed as a switched filter bank to accommodate multiple frequency bands.

Analog-to-digital conversion occurs at GA ADC 1263. GA ADC 1263 may be implemented as a set of ADCs in pairs or as a dual channel ADC. The digitized signal is then passed to VA FPGA 1265.VA FPGA 1265 converts the received digitized signals using conventional digital signal processing techniques and then processes the reconstructed bit stream (e.g., removes framing, training sequences, implements forward error correction and data encoding (e.g., using convolutional encoding, turbo encoding, hamming codes), decodes the security masked bit sequence), and delivers the bit stream to ground-side computing resources 1241 and external communication interfaces 1242 local to the wireless charger, possibly through intermediate processors, interfaces, and protocols (not shown). In the event of a fault event being detected (by the GA) or sent (by the VA), GA FPGA 1265 signals emergency shutdown 1244 (e.g., in the event of a coil fault or exceeding a thermal threshold), emergency shutdown 1244 disables charge signal 1245.

Closed-loop and open-loop control and reporting

ICCS 1101 actively measure the charge signal 1245 and the communication signals 1211 and 1227. The measurements may include received signal strength, bit error rate, and sum and difference of the signals 1227 received by the first and second antenna structures 1228, 1229, eb/No (ratio of energy per bit (Eb) to spectral noise density (No)), received Signal Strength Indication (RSSI), center frequency, and amplitude and phase shift at the first and second receive antennas 1228, 1229. The measurements may be delivered to a ground or VA digital control interface 1236 via a GA digital control interface 1241 for one or more vehicle-based processors 1250 for alignment detection and closed-loop charging system management and control.

Closed loop control may include providing near real-time voltage and current measurements (on VA), VA thermal measurements, Z-gap changes due to loading or unloading of the vehicle, soft VA or GA fault (cluster) alarms, alarms for intermediate charge performance events, and transmitting additional sensing on the vehicle side related to VA or vehicle electrical systems to GA and VA as needed to FPGA 1222.

VBMS 1239 use VA control digital interface 1238 to pass the commands for transmission to the charging system, which can command GA via GA control digital interface 1241.

Spread spectrum wideband signal

In one embodiment, the wideband signal for the full duplex VA-GA communication link is an asynchronous direct sequence spread spectrum signal using complementary code sequences. In some deployment scenarios, such as where the GA is deployed adjacently as a component of a larger macro GA cluster (e.g., as a single vehicle parking space charger), the distance cannot be relied upon to provide sufficient magnetic signal attenuation to mitigate co-channel interference between multiple GA-to-VA and VA-to-GA transmissions. The use of spread spectrum sequence techniques allows each of the GA and VA receivers to distinguish between signals transmitted by each receiver and co-channel interference. Complementary codes are used in direct sequence spread spectrum systems to allow correlation processing by the receiver to overcome co-channel interference and lack of synchronization between transmitters of GA and VA.

With sufficient distance between GA (and paired VA), signal attenuation of the magnetic signal allows code reuse, which in turn allows shorter code sequences. With shorter code sequences, the number of "chips" per bit in a direct sequence spread spectrum system can be minimized, resulting in a greater data rate over the same bandwidth.

In communication systems using inductive coupling for transmission, signal reflection and multipath are minimized by the inherent physics of magnetic field propagation. In one embodiment, direct sequence code spreading using complementary code sequences is designed to mitigate co-channel interference between closely located (clustered, adjacent or proximate) transmitters and receivers, such as in a wireless charging parking lot or lane.

The use of an asynchronous system allows multiple individual surface components (each having its own transmitter and receiver) to be deployed in an adjacent or close manner without the need for a shared real-time timing source. The lack of a need for a common timing source removes the need for clock recovery and/or phase locking between the GA and VA systems. Thus, each aligned GA and VA pair can communicate independently, regardless of the number of units deployed or the number of unit functions. If the GA is not paired with VA (due to a different deployment geometry or VA fault condition), the GA will not initiate a charge signal.

In an example embodiment, such a charging system may be used to charge a vehicle by positioning a VA of the vehicle relative to the GA to receive a charging signal. The coils of GA and VA are selectively enabled for charging based on the geometric positioning of VA relative to GA such that only aligned coils are activated. One or both of the transmission/reception systems of GA and VA are selected to have the same type of signal processing circuit, as the case may be. The transmit/receive system may then be used to transfer charge management and control data between the transmit/receive systems of GA and VA over the inductive link during charging.

As described above, the transmit/receive system may include hardware, software, and/or firmware that provides one or more of amplitude modulation, phase modulation, frequency modulation, orthogonal Frequency Division Multiplexing (OFDM), and spreading implementing techniques including at least one of direct sequence spreading, chirp spreading (CSS), binary quadrature keying (BOK), frequency hopping, and Direct Modulation (DM). For example, the types of transmission/reception systems are selected to be the same at the time of design/manufacture or by user selection. The VA and GA may then communicate software updates, diagnostic or telemetry information, and/or passenger entertainment service data therebetween during charging.

Fig. 13a shows a top view of a parking lot based wireless charging station deployed in a single row geographic arrangement 1301 in an example embodiment. Parking spaces 1304, 1305, 1306, and 1307 are defined by curb 1303 and painted line markers, as is typical. The travel lanes 1302 provide vehicle access to each parking space. In this example, each parking space 1304, 1305, 1306, and 1307 is mounted with a wireless charging Ground Assembly (GA) 1310, 1311, 1312, and 1313.GA 1310, 1311, 1312, and 1313 are shown as cluster assemblies of four adjacent individual GA's, although the length and width of the parking spaces may be other geometries.

The active GA1311, 1312, and 1313 radiate a magnetic communication signal 1315 before and during each charging session. Due to the propagation characteristics of the coupled magnetically induced signals and vertical antenna orientation, co-channel interference is confined within the GA cluster and may be between adjacent parking spots 1314.

The magnetic signal radiated by each active GA cluster 1311, 1312, and 1313 is one source of co-channel interference for each communication link (in this example, there are up to 8 signals per cluster, 4 signals from GA to VA when active, and 4 signals from VA to GA). Potential overlap or collision of magnetic signals 1315 from nearby parking spaces equipped with active GA 1312 or GA 1313 is also possible, but with sufficient physical separation 1309 between non-adjacent active GA 1311 and GA 1312 to greatly reduce or eliminate potential co-channel interference. Possible additional chargers across the driving lanes 1302 will have sufficient physical spacing 1308 to limit the possibility of co-channel interference.

Fig. 13b shows a top view of a parking lot based wireless charging station deployed in a double row geographic arrangement 1316 in an example embodiment. The GA-equipped parking double rows 1316 are isolated by the travel lane 1304. In this illustration, parking spaces 1317, 1320, 1321, and 1322 have a currently active GA, while parking spaces 1318, 1319, 1323, and 1324 are inactive (i.e., in an inactive state, parking spaces may be unoccupied or occupied, but have an inactive termination or charge that has not yet begun). The potential co-channel interference of a magnetically coupled full duplex communication system exists in the active parking space (the space where magnetic signals 1315 are radiated). Co-channel interference between each cluster of GAs in the macro GA (here, the macro GA is made up of 4 neighboring GAs, each with independent duplex communication) and potential co-channel interference 1314 between neighboring macro GAs are tolerated by the communication system. The same row of nearest active GA 1317 and GA 1320 or the cross row of nearest active GA 1322 and GA 1320 with sufficient geographic isolation 1309 is not a potential source of interference because the possible GA is geographically spaced 1308 across one or more travel lanes 1304 that provide access to the dual row charging station 1316.

Enabled communication links

In one embodiment, the full duplex link is always enabled during the charging cycle, providing continuous communication between VA and GA and secure transfer of vehicle software updates, diagnostics, telemetry, entertainment, and other information. ICCS 1101 support changes, modulation, and encoding of the transmit and receive frequencies to support specific events before, during, and after the charging session.

In a cluster deployment, each individual GA may support an independent communication link with each individual VA. In this way, the cluster GA may support individual VA or clustered VA (e.g., 1 row 2 VA, 2 row 2 VA, 3 row 2 VA, etc., up to the maximum width and length of the vehicle) or even operate VA by activating only a portion of the charging signals for the GA with geometrically corresponding VA. The use of independent communications eases deployment and operation because a single charging station can support multiple configured vehicles. Alternatively, the GA may be deployed as a coordinated cluster, where the individual GA and VA maintain communication once the charging signal is activated.

Static conditions

The duplex communication data link is used to provide authentication and access control for WPT in both static and dynamic charging scenarios. In addition, the data link may be used to provide information, software updates, diagnostic or telemetry information between the GA and VA, and passenger entertainment services. The continuous nature of the duplex data link results in faster feedback to the control system, such as deactivating the charge signal after detecting the introduction of foreign matter between VA and GA. Positioning the communication system receiver on the physical periphery of the charging coil also allows for earliest detection of an introduced obstruction.

Dynamic conditions

In an embodiment of the dynamic charging situation, the communication link is maintained as the vehicle moves along the equipped railway or highway. In this deployment, using ICCS, which enables a Direct Sequence Spread System (DSSS), the code sequence is selected to be as short as possible and orthogonal to the neighboring GA, allowing for fast soft handoff between GA. Using a magnetic induction communication link, the expected sequence of GA and associated code sequences may be uploaded to the vehicle to increase the allowable speed on the traffic lane or railway in which the GA is equipped. Using the uploaded sequence, ICCS can be preloaded to demodulate and decode the communication signal faster.

Fig. 14 shows one example of a highway 1401 that can be used for dynamic charging. The expressway is provided between the two curbs 1402 and 1403, and is divided into a traveling lane 1405 and a charging lane 1406. These charging lanes may have a set speed and set inter-vehicle gap length to better optimize charging. The charging lane speed is set to manage the charging time (also referred to as dwell time) on each sequential GA 1407. Vehicles 1404 and 1409 can move into a charging lane (shown here as having different lane markings or physical separation 1408) at will or at designated entry points.

In the railway example, a sequence or array of GAs (sequential clusters) for charging railcars equipped with VA is placed between tracks (up to one gauge width). The GA may also be a VA that is facing deployment on the side(s) or top of the railcar.

By having multiple GA's arranged sequentially along the travel path, customization of the GA (e.g., longer antennas (charging and communication)) can be deployed and provide autonomous vehicle control information for optimal charging at the current lane and possible charger sites along the possible routes.

Independent communication path of each component

In one embodiment, a full duplex inductively coupled data link is deployed for each member of an independent GA (macro GA) cluster. Similarly, each individual VA (part of a macro VA cluster) is equipped with a full duplex inductively coupled data link.

This independent operation of the data link gives the lowest latency communication by eliminating the circuitry and processing required to coordinate the communication between the components when the components are clustered. Lack of coordination also means faster link startup because concurrent data link establishment per component pair (GA to VA) is allowed.

Independent data links also facilitate the deployment of single and multiple components. Geometrically arbitrary GA clusters can be deployed in any area or pattern needed to support vehicle size and scaled power requirements.

By making each VA and GA functionally identical (e.g., with identical magnetic induction antennas and common resonant induction coil units), economies of scale can be achieved. The common resonant induction coil unit is also used to increase the efficiency of the charging signal, thereby increasing ICCS overall power efficiency.

The independent nature of the paired GA-to-VA configuration means that a single GA failure or VA failure in the cluster deployment is gracefully downgraded to a lower state of charge via the remaining GA-VA pairs. In one aspect, failure of the VA unit produces an immediate shut-off of the charge signal from the paired GA. Since the GA is no longer radiating, the vehicle is not heated from the charge signal that is no longer terminated.

Those skilled in the art will appreciate that the topologies and circuit implementations described herein can be effectively implemented as a single application specific integrated circuit, a discrete integrated circuit, a multi-chip module, and/or as software executing on a digital signal processing circuit having ancillary a/D and D/a circuits. Further, while the disclosure contained herein relates to providing power to a vehicle, it should be understood that this is but one of many possible applications and that other embodiments are possible, including non-vehicle applications. For example, those skilled in the art will appreciate that there are many applications in non-vehicular inductive charging applications that provide a full duplex data link, such as portable consumer electronic device chargers, such as those used to charge toothbrushes, cell phones, and other devices (e.g., powerMat ^TM). Furthermore, those skilled in the art will appreciate that simultaneous amplitude and angle modulation using other complex modulation methods may be used, as well as increasing the transmission bandwidth (data rate) of the communication system described herein by using multiple modulated forward and reverse path carriers. Accordingly, these and other such applications are included within the scope of the claims.

Claims (29)

1. A vehicle charging system, comprising:

A ground assembly comprising one or more coils, wherein each coil has a full duplex inductively coupled data communication system comprising a first transmit/receive system that transmits a first signal over a first inductive link and receives a second signal over a second inductive link, and

A vehicle component comprising one or more coils, wherein each coil has a full duplex inductively coupled data communication system comprising a second transmit/receive system that receives the first signal over the first inductive link and transmits the second signal over the second inductive link,

Wherein the first and second transmission/reception systems are adapted to use and switch between circuitry for at least two of amplitude modulation, phase modulation, frequency modulation, orthogonal frequency division multiplexing, OFDM, or a spreading circuit implementing a technique comprising at least one of direct sequence spreading, chirping spreading, CSS, binary quadrature keying, BOK, frequency hopping, or direct modulation, DM,

Wherein the coil of the ground assembly is configured to be arranged in parallel with the coil of the vehicle assembly to transmit a charging signal during charging and to be selectively activated during charging to match the geometry of the vehicle assembly, and

Wherein at least one of the first and second transmission/reception systems is adapted to enable a user to switch hardware, software and/or firmware of at least one of the first and second transmission/reception systems during use, whereby the first and second transmission/reception systems have the same type of hardware, software and/or firmware during charging of the vehicle.

2. The vehicle charging system of claim 1, wherein the ground assembly includes a processor that processes data from the ground assembly and an external system for transmission to the vehicle assembly and processes data received from the vehicle assembly for delivery to the ground assembly and the external system for processing.

3. The vehicle charging system of claim 2, wherein the processor disables the charging signal when the ground component detects a fault event or when a fault event is received from the vehicle component.

4. The vehicle charging system of claim 1, wherein the vehicle component comprises a processor that processes at least one of commands or data from the vehicle component or from at least one of a vehicle battery management system, a vehicle occupant information system, or a vehicle entertainment system for transmission to the ground component and processes data received from the ground component for delivery to the vehicle component and at least one of the vehicle battery management system, the vehicle occupant information system, or the vehicle entertainment system.

5. The vehicle charging system of claim 4, wherein the vehicle component further comprises a digital interface, and the processor provides measurements related to the first signal, the second signal, and the charging signal to the digital interface.

6. The vehicle charging system of claim 5, wherein the vehicle component comprises a first antenna structure and the ground component comprises a second antenna structure, and wherein the measurement comprises at least one of a signal strength, an error rate, and a sum-difference of a first signal or a second signal received by the first antenna structure and the second antenna structure, respectively, a ratio of energy per bit to spectral noise density, a received signal strength indication, a center frequency, or a magnitude and a phase shift at the first antenna structure and the second antenna structure.

7. The vehicle charging system of claim 6, further comprising a vehicle-based processor, wherein the measurement is delivered to the vehicle-based processor via the digital interface for at least one of alignment detection or closed loop charging system management and control.

8. The vehicle charging system of claim 7, wherein the vehicle-based processor provides to the processor for transmission near real-time voltage and current measurements on the vehicle component, thermal measurements of the vehicle component, Z-gap changes due to loading or unloading of the vehicle, fault alarms of vehicle components or ground components, alarms regarding intermediate charging performance events, and additional vehicle sensing data related to the vehicle component or vehicle electrical system.

9. The vehicle charging system of claim 1, wherein the first signal and the second signal are configured as narrowband signals or wideband signals depending on a stage of a charging cycle or whether a threshold of signal quality has been crossed.

10. The vehicle charging system of claim 1, wherein the first signal and the second signal are configured as asynchronous spread spectrum signals using a complementary code sequence.

11. The vehicle charging system of claim 10, wherein the first and second transmission/reception systems each comprise a direct sequence spread spectrum system that transmits a code sequence that enables the first and second transmission/reception systems to distinguish between signal and co-channel interference.

12. The vehicle charging system of claim 11, wherein the code sequence is a complementary code sequence.

13. The vehicle charging system of claim 1, wherein the first and second transmission/reception systems each comprise a receiver, an analog-to-digital converter, a digital processor, a digital-to-analog converter, or a transmitter, the digital processor processing data from at least one of the ground component or an external system for transmission to the vehicle component and processing data received from the vehicle component for delivery to at least one of the ground component or the external system for processing.

14. The vehicle charging system of claim 13, wherein the analog-to-digital converter and the digital-to-analog converter are implemented as discrete integrated circuits and the digital processor is implemented as a field programmable gate array.

15. The vehicle charging system of claim 13, wherein the analog-to-digital converter, digital processor, and digital-to-analog converter are implemented as firmware residing in an application specific integrated circuit ASIC.

16. The vehicle charging system of claim 13, wherein the digital processor of each transmit/receive system processes input data for transmission and processing data received from other transmit/receive systems using a software structure implemented on the digital processor.

17. The vehicle charging system of claim 13, wherein the first and second transmission/reception systems each further comprise at least one bandpass filter.

18. A method of charging a vehicle, comprising:

Positioning a vehicle component of a vehicle relative to a ground component for receiving a charging signal, the vehicle component comprising one or more coils, wherein each coil has a full duplex inductively coupled data communication system comprising a first transmit/receive system that receives a first signal over a first inductive link and transmits a second signal over a second inductive link, and the ground component comprising one or more coils, wherein each coil has a full duplex inductively coupled data communication system comprising a second transmit/receive system that transmits the first signal over the first inductive link and receives the second signal over the second inductive link;

Selectively enabling a coil of the ground assembly and a coil of the vehicle assembly for charging based on a geometric positioning of the vehicle assembly relative to the ground assembly;

Enabling a user to switch hardware, software and/or firmware of at least one of the first and second transmit/receive systems during use, whereby the first and second transmit/receive systems have the same type of hardware, software and/or firmware during charging of the vehicle, wherein the switching comprises switching at least one of the first or second transmit/receive systems between at least two of an amplitude modulation circuit, a phase modulation circuit, a frequency modulation circuit, an orthogonal frequency division multiplexing, OFDM, circuit or a spread spectrum circuit implementing a technique comprising at least one of direct sequence spread spectrum, chirped spread spectrum, CSS, binary orthogonal keying BOK, frequency hopping, or direct modulated DM, and

Charge management and control data is transferred between the first and second transmit/receive systems over the first and second inductive links during charging.

19. The method of claim 18, further comprising communicating at least one of a software update, diagnostic or telemetry information, or passenger entertainment service data between the ground component and the vehicle component via the first inductive link and the second inductive link during charging.

20. The method of claim 18, further comprising disabling the charging signal when the ground component detects a fault event or receives a fault event from the vehicle component.

21. The method of claim 18, further comprising the first transmit/receive system processing at least one of commands or data from the vehicle component or from an external system for transmission to the surface component and processing data received from the surface component for delivery to at least one of the external system and the vehicle component.

22. The method of claim 21, further comprising providing measurements related to the first signal, the second signal, and the charging signal to a digital interface for processing.

23. The method of claim 22, wherein the vehicle component comprises a first antenna structure and the ground component comprises a second antenna structure, and wherein the measurement comprises at least one of signal strength, energy per bit to spectral noise density ratio, frequency, or amplitude and phase shift at the first and second antenna structures.

24. The method of claim 23, further comprising delivering the measurement to an external processor via the digital interface for at least one of alignment detection or closed loop charging system management and control.

25. The method of claim 24, further comprising transmitting at least one of near real-time voltage and current measurements on the vehicle component, thermal measurements of the vehicle component, Z-gap changes due to loading or unloading of a vehicle containing the vehicle component, a fault alert of a ground component or vehicle component, an alert regarding an intermediate charging performance event, or additional sensed data related to the vehicle component from the vehicle component to the ground component.

26. The method of claim 18, further comprising configuring the first signal and the second signal as narrowband signals or wideband signals based on a stage of a charging cycle or whether a threshold of signal quality has been crossed.

27. The method of claim 18, further comprising configuring the first signal and the second signal as asynchronous spread spectrum signals.

28. The method of claim 27, further comprising transmitting a code sequence between the first transmit/receive system and the second transmit/receive system that enables the first transmit/receive system and the second transmit/receive system to distinguish between signal and co-channel interference.

29. The method of claim 28, wherein transmitting the code sequence comprises transmitting a complementary code sequence.