HK40088946B - Torque sensing device - Google Patents

Description

Torque sensor

Priority Statement

This application claims the benefit of priority to U.S. Patent Application No. 17/106,720, filed November 30, 2020, entitled “Torque Sensing Device and Method,” which claims the benefit of U.S. Provisional Application No. 63/037,652, filed June 11, 2020, entitled “Torque Sensing Device and Method,” which is incorporated herein by reference.

Technical Field

This disclosure generally relates to torque sensors, and more specifically, to a system for inductively detecting torque between a first component and a second component.

Background Technology

Various types of torque sensors for detecting torque between a first component and a second component are known. In some cases, one component may carry a sensing element, while the other component may carry a magnetic or conductive target. The sensing element can be configured to detect torque based on the electromagnetic field caused by the position of the soft magnetic or conductive target relative to the sensing element.

Summary of the Invention

Various aspects and advantages of the embodiments disclosed herein will be set forth in part in the description which follows, or may be learned from the description, or may be learned by practice of these embodiments.

One example aspect of this disclosure relates to a torque sensor. The torque sensor includes at least one excitation coil. The torque sensor includes at least one oscillating circuit coupled to the excitation coil. The oscillating circuit is configured to generate a periodic voltage signal and to power the excitation coil using the periodic voltage signal. The torque sensor includes a first channel. The first channel includes a first receiver. The first receiver may include a plurality of periodically repeating first receiver structures. The first channel may include a first rotor target configured to be coupled to a first rotor. The first rotor target may be configured to influence the strength of the inductive coupling between the excitation coil and the first receiver. The torque sensor may include a second channel. The second channel may include a second receiver. The second receiver includes a plurality of periodically repeating second receiver structures. The second channel includes a second rotor target configured to be coupled to a second rotor. The second rotor target may be configured to influence the strength of the inductive coupling between the excitation coil and the second receiver. The torque sensor may include processing circuitry configured to provide a first signal associated with the first channel, the first signal indicating the position of the first rotor target relative to the first receiver. The processing circuitry can be configured to provide a second signal associated with the second channel, indicating the position of the second rotor target relative to the second receiver. The torque sensor includes one or more features to reduce electromagnetic coupling between the first and second channels.

These and other features, aspects, and advantages of the various embodiments will become better understood with reference to the following description. The accompanying drawings, which are included in and form part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the relevant principles.

Attached Figure Description

For those skilled in the art, the embodiments are discussed in detail in the specification with reference to the accompanying drawings, in which:

Figure 1 depicts a schematic diagram of a selection portion of a torque sensor including processing circuitry according to an exemplary embodiment of the present disclosure;

Figure 2 depicts a schematic diagram of a torque sensor according to an exemplary embodiment of the present disclosure;

Figure 3 depicts a plan view of the first rotor target and the electromotive force generated in the sinusoidal winding of the first receiver according to an exemplary embodiment of the present disclosure;

Figure 4 depicts a plan view of the second rotor target and the electromotive force generated in the sinusoidal winding of the second receiver according to an exemplary embodiment of the present disclosure;

Figure 5 depicts a plan view of a second rotor target according to an exemplary embodiment of the present disclosure, the second rotor target including a ferrite portion;

Figure 6 depicts a plan view of a portion of a plurality of rotor targets according to various aspects of the present disclosure;

Figure 7 depicts a plan view of a portion of a plurality of receiver structures according to various aspects of this disclosure;

Figure 8 depicts a plan view of a plurality of rotor targets according to various aspects of this disclosure; and

Figure 9 depicts a plan view of a plurality of rotor targets according to various aspects of the present disclosure, each rotor target having a resonant target structure and a non-resonant target structure.

Detailed Implementation

Reference will now be made in detail to embodiments, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation and not by way of limitation of the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments without departing from the scope of the present disclosure. For example, features shown or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, these modifications and variations are intended to be covered by all aspects of the present disclosure.

The exemplary aspect of this disclosure relates to a torque sensor, which determines the torque of the device based on a signal associated with the position of a receiver located on the device relative to a corresponding rotor target. The disclosed techniques can be used to improve the accuracy of torque measurement using a variety of techniques. In particular, the disclosed techniques use various techniques and configurations to ensure decoupling (e.g., electromagnetic coupling) between multiple receiving coils and/or multiple target structures in different channels of the torque sensor. For example, these techniques may include: having rotor targets made of different types of materials; using different ratios of receiver period to rotor target; generating a time-varying magnetic field in one rotor target with a phase shift relative to another rotor target; and arranging the rotor such that the rotor targets are geometrically decoupled.

Torque sensors can be configured to determine the torque of devices, including those used to operate motor vehicles. For example, accurately determining the torque of a device (e.g., the steering column of a motor vehicle) can improve the operational safety of the vehicle in question. A torque sensor can determine the torque on the steering column by using the inductive coupling strength between the rotor target of the torque sensor disposed in the steering column of the vehicle and the corresponding receiver structure, based on the relative position of the rotor target.

The torque sensor may include multiple channels, such as a first channel and a second channel. An oscillating circuit coupled to an excitation coil may be configured to generate a periodic voltage signal. The torque sensor may also include a stator circuit board comprising multiple receivers, such as one or more receivers associated with each channel. The torque sensor may include corresponding rotor targets for each channel, such as a first rotor target and a second rotor target coupled to different rotors. Furthermore, the torque sensor may include processing circuitry configured to provide, for each channel, a signal associated with the position of the rotor target relative to the receiver structure, and thus with the position of the rotor. These signals can be processed to determine the torque.

More specifically, the torque sensor may include at least one excitation coil coupled to at least one oscillation circuit. The oscillation circuit may be configured to generate a periodic voltage signal and use this periodic voltage signal to power the excitation coil. The periodic voltage signal (and the resulting current) may induce an electromotive force in a plurality of receivers, each including a plurality of receiver structures. Each of these receiver structures may repeat periodically within the receiver. Each of the plurality of receivers may be a receiving coil (e.g., a sine winding and/or a cosine winding). Each of the plurality of receiving coils may have its own period and may be configured to be electromagnetically coupled to a corresponding rotor target. In some embodiments, the plurality of receivers may include a first receiver and a second receiver. The first receiver may be associated with a first channel. The second receiver may be associated with a second channel.

The magnetic field generated by the current flowing through the excitation coil can induce an electromotive force (e.g., through an electromagnetic field) in each receiver. This electromotive force generates a signal that depends on the position of the respective rotor target relative to the corresponding receiver and the excitation coil among a plurality of receivers. For example, the electromagnetic field of the first rotor target can be detectably adjusted based on the position of the first rotor target relative to the first receiver. Furthermore, the electromagnetic field of the second rotor target can be detectably adjusted based on the position of the second rotor target relative to the second receiver. The signals induced in the first and second receivers can be processed to determine the torque.

One example aspect of this disclosure relates to a torque sensor. The torque sensor includes at least one excitation coil. The torque sensor includes at least one oscillating circuit coupled to the excitation coil. The oscillating circuit is configured to generate a periodic voltage signal and to power the excitation coil using the periodic voltage signal. The torque sensor includes a first channel. The first channel includes a first receiver. The first receiver may include a plurality of periodically repeating first receiver structures. The first channel may include a first rotor target configured to be coupled to a first rotor. The first rotor target may be configured to influence the strength of the inductive coupling between the excitation coil and the first receiver. The torque sensor may include a second channel. The second channel may include a second receiver. The second receiver includes a plurality of periodically repeating second receiver structures. The second channel includes a second rotor target configured to be coupled to a second rotor. The second rotor target may be configured to influence the strength of the inductive coupling between the excitation coil and the second receiver. The torque sensor may include processing circuitry configured to provide a first signal associated with the first channel, the first signal indicating the position of the first rotor target relative to the first receiver. The processing circuitry can be configured to provide a second signal associated with the second channel, indicating the position of the second rotor target relative to the second receiver. The torque sensor includes one or more features to reduce electromagnetic coupling between the first and second channels.

In some embodiments, M is the number of second receiver structures and N is the number of first receiver structures, such that M = 2N ± 1. In these embodiments, the first rotor target may have a plurality of periodically repeating target lobes. Each target lobe may have an angle width. The angle width of each target lobe in the first rotor target is approximately equal to the angle width corresponding to a single cycle of the plurality of second receiver structures in the second receiver.

In some embodiments, the structural phase of the second receiver varies both circumferentially and radially along the second receiver. A radial structural phase shift occurs at a specific point along that radial direction of the second receiver. The structural phase shift can be approximately 180° (e.g., opposite phases).

In some embodiments, the structural phase of the second rotor target varies circumferentially and radially along the rotor target in a manner corresponding to the second receiver. A first portion of the second rotor target may include, for example, a conductive material, and a second portion of the second rotor target may include a magnetic and non-conductive material.

In some embodiments, the structural phase of the first receiver may vary circumferentially along the first receiver and remain constant radially along the first receiver. The structural phase of the first rotor target varies circumferentially along the first rotor target in a manner corresponding to the first receiver and remains constant radially along the first rotor target.

In some embodiments, the structural phase of the first receiver varies continuously along at least a portion of its radial direction. The structural phase of the second receiver also varies continuously along at least a portion of its radial direction. In some cases, the first and second receivers have radial structural phase variations in their respective structures, these phase variations having approximately equal magnitudes but opposite directions relative to each other.

In some embodiments, the time-varying magnetic field generated by the first rotor target is phase-shifted relative to the time-varying magnetic field generated by the second rotor target. The time-varying magnetic field generated by the first rotor target may be phase-shifted by approximately 90° relative to the time-varying magnetic field generated by the second rotor target. The second rotor target includes a resonant circuit having an inductor and a capacitor.

In some embodiments, the plurality of target protrusions do not repeat continuously around the entire circumference of the second receiver. The plurality of target protrusions in the first rotor target have a cumulative overlap of less than 120° with the plurality of target protrusions in the second rotor target. For example, the plurality of target protrusions includes a first set of target protrusions and a second set of target protrusions, the first set of target protrusions being located approximately 180° from the second set of target protrusions.

The disclosed technology provides numerous technical effects and benefits, including improved accuracy of torque detection using torque sensors. In particular, the disclosed technology employs various techniques and configurations to ensure electromagnetic decoupling between the first and second channels in the torque sensor. This allows for more accurate determination of torque applied to various applications (e.g., automotive applications, such as torque in the steering column).

A torque sensor according to an exemplary embodiment of the present disclosure will now be described with reference to Figures 1 through 9.

Figure 1 illustrates a schematic diagram of a selection portion of a single channel of a torque sensor including processing circuitry according to an exemplary embodiment of the present disclosure. As shown in Figure 1, in this example, the torque sensor 100 includes an excitation coil formed by an excitation winding 1, one or more receiving coils formed by a first detection winding 3 (hereinafter referred to as the sine winding 3) and a second detection winding 5 (hereinafter referred to as the cosine winding 5), and a rotor target 7. Furthermore, the rotor target 7 may be associated with the sine winding 3 and the cosine winding 5. The excitation coil and the receiving coil may be formed on a first member (not shown), and the rotor target 7 may be formed on a second member (also not shown), in such a way that the relative movement between the first member and the second member causes, on the one hand, a corresponding relative movement (e.g., rotational movement) between the excitation coil and the receiving coil and on the other hand, the rotor target 7.

For purposes of illustration and discussion, various aspects of this disclosure are discussed with reference to multiple receiving coils having sine and cosine windings. Those skilled in the art will understand using the disclosure provided herein that any number of windings/coils with any suitable spacing (e.g., three windings with a 120° spacing) can be used without departing from the scope of this disclosure.

Each of the excitation winding 1, the sine winding 3, and the cosine winding 5 can be formed by a corresponding conductive winding, the end of which is electrically coupled to a corresponding terminal of a processing circuit (e.g., integrated circuit 9), which is, for example, an application-specific integrated circuit (ASIC) or an application-specific standard product (ASSP). In other examples, integrated circuit 9 may alternatively utilize multiple interconnected devices and/or may be implemented using one or more suitable components (e.g., multiple electronic components, such as discrete electronic components).

As shown in Figure 1, integrated circuit 9 includes a transmit (“TX”) drive stage 11 that generates an alternating current signal to supply to the excitation coil. In this example, the TX drive stage 11 is a free-running oscillator that generates the alternating current signal at a drive frequency determined based on the inductance of the excitation coil and the capacitance of the capacitor 13 connected in parallel with the excitation winding 1.

Alternating current is supplied to the excitation winding 1, inducing an electromotive force (EMF) in the sine winding 3 and the cosine winding 5, causing current to flow in the sine winding 3 and the cosine winding 5. Due to the arrangement of the sine winding 3 and the cosine winding 5 relative to the excitation winding 1, the EMF induced directly in the sine winding 3 and the cosine winding 5 is balanced, resulting in a negligible current flowing in the sine winding 3 and the cosine winding 5. However, the EMF induced through the rotor target 7 causes current to flow in the sine winding 3 and the cosine winding 5. As shown in Figure 1, the sine winding 3 and the cosine winding 5 are separate windings, resulting in separate current flows in the sine winding 3 and the cosine winding 5. The sine winding 3 and the cosine winding 5 are electrically coupled to different terminals of the integrated circuit 9. The current flowing in the sine winding 3 is processed to provide a sine output signal 23, and the current flowing in the cosine winding 5 is processed to provide a cosine output signal 25. The relative amplitudes of the sine output signal 23 and the cosine output signal 25 indicate the relative positions of the first component and the second component.

The current flowing in the sinusoidal winding 3, upon entering the integrated circuit 9, first passes through the electromagnetic compatibility (EMC) filter stage 15 to reduce signal components located far from the drive frequency. For example, the filtered signal components may be caused by interference from electrical signals generated by other surrounding electronic components.

The filtered electrical signal then passes through a synchronous demodulation stage 17, where it is mixed with the demodulated signal from the TX drive stage 11. The demodulated signal then passes through a low-pass filter stage 19 to remove high-frequency components corresponding to the harmonics of the drive signal, leaving only the baseband components. This signal then passes through a gain and output buffer stage 21, which allows an adjustable gain to be applied before the processing circuit 9 outputs the sinusoidal output signal 23. These signals can then be processed to determine the torque. As can be clearly seen in Figure 1, the current induced in the cosine winding 5 also passes through the EMC filter 15, synchronous demodulation 17, low-pass filter 19, and gain and output buffer 21 within the processing circuit 9 before being output as the cosine output signal 25.

Figure 2 illustrates a schematic diagram of a torque sensor according to an exemplary embodiment of the present disclosure. The torque sensor 200 may include multiple channels for detecting the position of two rotors relative to a component (e.g., in a steering column). As shown in Figure 2, the torque sensor 200 may include a stator circuit board 220. The stator circuit board 220 may be disposed between a first rotor 208 and a second rotor 210. The first rotor 208 and the second rotor 210 may be configured to be rotatable relative to each other and/or rotatable relative to the stator circuit board 220. In addition to an oscillation circuit (not shown), the torque sensor 200 may also include an excitation coil (not shown). The oscillation circuit may be configured to generate a periodic alternating current signal and may couple this periodic alternating current signal into the excitation coil during operation of the torque sensor 200.

In some embodiments, the torque sensor 200 can be used to determine the torque (e.g., steering torque) of a steering device (including the steering column of a vehicle). As shown, the steering column 222 includes a torque element 206 (torsion spring element) that can be positioned between a steering column portion 202 and a steering column portion 204. The steering torque can be determined at least in part based on the torque of the portion of the steering column 222 in which the torque element 206 is disposed. Furthermore, the torque of the steering column portion 202 relative to the steering column portion 204 can be determined.

A first rotor 208 may be disposed at a first end of a torque element 206, and a second rotor 210 may be disposed at a second end of a torque element 206 opposite to the first end. The stator circuit board 220 may include a first receiver 216 and a second receiver 218 on the side facing the first rotor 208 and the side facing the second rotor 210, respectively. Furthermore, a first rotor target 212 may be coupled to the first rotor 208. A second rotor target 214 may be coupled to the second rotor 210. In some embodiments, the first rotor 208 and/or the second rotor 210 may include a plurality of corresponding target protrusions (discussed in detail below).

A first receiver 216 (e.g., a sine and/or cosine winding) may be associated with a first rotor target 212, and the side of the first receiver 216 facing the first rotor target 212 may have N periodically repeating receiver structures. A second receiver 218 (e.g., a sine and/or cosine winding) may be associated with a second rotor target 214, and the side of the second receiver 218 facing the second rotor target 214 may have M periodically repeating receiver structures. The first receiver 216 and the second receiver 218 may be implemented as receiving coils, each receiver in the first receiver 216 and the second receiver 218 including a periodically repeating ring structure, each periodically repeating ring structure forming a receiver structure for the first receiver 216 and a receiver structure for the second receiver 218. Each periodically repeating structure forms a receiver structure. In some embodiments, the number M of second receiver structures for the second receiver is determined based on the number N of the first receiver structures, such that M = 2N. In some embodiments, the number M of second receiver structures for the second receiver is determined based on the number N of the first receiver structures, such that M = 2N ± 1.

The first rotor 208 may include a first rotor target 212 associated with a first channel of the torque sensor 200. The second rotor 210 may include a second rotor target 214 associated with a second channel of the torque sensor 200. Rotation of the first rotor 208 may change the alignment between the first rotor target 212 and a corresponding first receiver 216 in the first channel, thereby changing the strength of the inductive coupling between the first rotor target 212 and the first receiver 216. Rotation of the second rotor 210 may change the distance between the second rotor target 214 and a second receiver 218 in the second channel, thereby changing the strength of the inductive coupling between the second rotor target 214 and the second receiver 218. This change in the strength of the inductive coupling may be processed to determine a signal representing the position of the first rotor 208 and the second rotor 210. The torque (e.g., steering torque) of the steering column portion 202 and the steering column portion 204 may be determined at least in part based on the position of the first rotor target relative to the first receiver structure (e.g., a first measured rotation angle) and the position of the second rotor target relative to the second receiver structure (e.g., a second measured rotation angle). The difference between two measured rotation angles (e.g., the angle difference method) can be used to determine torque.

Figures 3 and 4 depict rotor targets and receivers for different channels of a torque sensor according to an exemplary embodiment of this disclosure. For example, when the number M of second receiver structures in the second receiver is determined based on the number N of first receiver structures such that M = 2N, the configuration of the rotor target and receiver described with reference to Figures 3 and 4 can be used to reduce interference between multiple channels in the torque sensor. For example, the configuration of the rotor target and receiver described with reference to Figures 3 and 4 can also be used when the number M of second receiver structures in the second receiver is determined based on the number N of first receiver structures such that M = 2N ± 1.

For example, FIG3 depicts a plan view of a conductive material pattern of a first rotor target 212 for a first channel of a torque sensor (e.g., torque sensor 200) according to an exemplary embodiment of the present disclosure and a corresponding first receiver 216 (e.g., a sinusoidal winding). As shown, the first rotor target 212 may include a plurality of target convex corners 302 (e.g., four target convex corners).

The first rotor target 212 includes alternating structural phases in the circumferential direction. For example, a first structural phase corresponds to the presence of a target convex angle 302. A second structural phase corresponds to the absence of a target convex angle 302. As shown, the structural phase of the first rotor target 212 is constant in the radial direction but varies in the circumferential direction. For example, in the first rotor target 212, there is a structural phase shift every 45°. Thus, at the scale of the receiver 216, there can be an electrical phase shift every 180°.

An example target convex corner 306 extends between 310 and 312 and has an angle width 308. The angle width 308 of each target convex corner is mechanically approximately 45° on the target scale and there is an electrical phase shift every 180° on the receiver 216 scale. The angle width 308 of each target convex corner in the first rotor target 212 can be selected to reduce coupling with the first receiver 216. For example, in some embodiments, the angle width may be equal to the period of each receiver structure on the first receiver 216.

The first receiver 216 may include a shaped receiving coil such that the signal received on the receiving coil varies sinusoidally with the target position. Like any sine curve, the receiving coil may have both amplitude and phase. The structural phase of the receiving coil may vary with position along the measurement path. More specifically, the receiving coil may have multiple receiver structures that exhibit sinusoidal variation. By using different winding directions (clockwise and counterclockwise), each receiver structure may be associated with either a positive structural phase or a negative structural phase. For example, in the example of Figure 3, the first receiver 216 may include multiple positive receiver structures 316 and multiple negative receiver structures 318. As shown, the first receiver 216 may have a structural phase that is constant radially (e.g., remains positive or negative) but varies circumferentially (e.g., changes from positive to negative or vice versa).

Various aspects of this disclosure are discussed with reference to the shape of a sinusoidal receiving coil. Those skilled in the art will understand using the disclosure provided herein that other methods of obtaining the sinusoidal response from the coil can be used without departing from the scope of this disclosure, such as approximating the sine wave as a "square wave" shape, appropriately positioning a "box-shaped" or "square" coil, separating it from a target to smooth the "square wave" response, etc.

Figure 4 depicts a plan view of a second rotor target 214 and a second receiver 218 according to an exemplary embodiment of the present disclosure. As shown, the second rotor target 214 may include a plurality of target convex corners 402. The second rotor target 214 includes alternating structural phases in the circumferential and radial directions. For example, a first phase corresponds to the presence of a target convex corner 402. A second phase corresponds to the absence of a target convex corner 402. As shown, the structural phases of the second rotor target 214 may vary circumferentially. For example, in the second rotor target 214, there is a structural phase shift every 45° circumferentially. Furthermore, the second rotor target 214 includes alternating phases in the radial direction. For example, a first structural phase may correspond to the exterior of the second rotor target 214, including an outward convex corner portion 404. Furthermore, a second structural phase may correspond to the interior of the second rotor target 214, including an inward convex corner portion 406 (where no conductor is present). The boundary between the exterior and interior of the second rotor target 214 (e.g., structural phase shift) is represented by a specific point 408. As shown in the figure, the phase of the second rotor target 214 varies radially and circumferentially. Furthermore, the phase of the second rotor target 214 can vary in a manner corresponding to the second receiver 218.

Positive and negative portions of multiple example receiver structures in example second receiver 218 are shown in FIG. 4. As shown, second receiver 218 may have a structural phase that varies radially and circumferentially (e.g., from positive to negative or vice versa). As an example of a circumferentially varying structural phase of second receiver 218, a first phase may correspond to portion 410 of second receiver 218, and a second phase may correspond to portion 412 of second receiver 218. As an example of a radially varying phase, a first phase may correspond to portion 414 of second receiver 218, and a second phase may correspond to portion 412 of second receiver 218. Furthermore, a radial structural phase shift of second receiver 218 may occur at a specific point along the radial direction of second receiver 218. For example, a radial structural phase shift of second receiver 218 may occur at point 416. In some embodiments, the radial structural phase shift may be approximately 180° (e.g., a phase shift from portion 414 to portion 412).

Figure 5 depicts a plan view of a second rotor target according to an exemplary embodiment of the present disclosure. The second rotor target 214 may include portions of conductive material and portions of magnetic and non-conductive material. For example, the outer convex portion 504 of one of the plurality of target convex angles 502 may include conductive material. Furthermore, the inner convex portion 506 of the same convex angle may include magnetic and non-conductive material. In some embodiments, the inner convex portion 506 may include or be covered with ferrite to enhance the magnetic field of the inner convex portion 506. Thus, the phase of the second rotor target 214 can vary radially and circumferentially.

In some embodiments, the two channels of the torque sensor may include rotor targets and receivers with identical configurations, such as the configuration described with reference to FIG3. However, in this case, to reduce interference between channels, the number M of second receiver structures in the second receiver is determined based on the number N of the first receiver structures, such that M = 2N ± 1. In this case, in some embodiments, the angular width of each target convex angle of the first rotor target of the first channel may be adjusted to be approximately equal to the angular width corresponding to a single cycle of the plurality of second receiver structures of the second receiver of the second channel.

Figure 6 depicts a plan view of a portion of an example rotor target according to an exemplary aspect of this disclosure. Figure 6 shows a first rotor target 212 (also depicted in Figure 2) configured orthogonally to a second rotor target 214. The first rotor target 212 may include a plurality of target convex angles 606 (e.g., four target convex angles), including target convex angles 608. The first rotor target 212 includes alternating phases in the circumferential direction. For example, a first phase corresponds to the presence of target convex angle 608. A second phase may correspond to the absence of target convex angle 608 or the absence of any one of the plurality of target convex angles 606. Thus, the phase of the first rotor target 212 can vary circumferentially along the first rotor target 212. Furthermore, the phase of the first rotor target 212 can be continuously varied radially along the first rotor target 212.

Furthermore, the second rotor target 214 may include a plurality of target convex angles 610 (e.g., four target convex angles), including target convex angles 612. The second rotor target 214 includes alternating phases in the circumferential direction. For example, a first phase corresponds to the presence of target convex angle 612. A second phase corresponds to the absence of target convex angle 612 or the absence of any one of the plurality of target convex angles 610. Furthermore, the phase of the second rotor target 214 may be continuously variable in the radial direction. The radial structural phase changes of the first rotor target 212 and the second rotor target 214 have approximately equal magnitudes but are in opposite directions relative to each other.

Figure 7 depicts a plan view of a portion of a plurality of receiver structures according to various aspects of the present disclosure. Figure 7 shows a plurality of first receiver structures 702 of a first receiver 216 (also depicted in Figure 2). The first receiver 216 may include alternating phases in the circumferential direction. For example, a first phase corresponds to receiver structure 714. A second phase corresponds to receiver structure 718. Thus, the phase of the first receiver 216 varies along the circumferential direction of the first receiver 216. Furthermore, the phase of the first receiver 216 may vary continuously along at least a portion of the radial direction of the first receiver 216. For example, a portion (e.g., a positive portion) corresponding to receiver structure 714 may correspond to the first phase, and a portion 724 (e.g., a negative portion) may correspond to the second phase, thereby changing the phase in the radial direction of the first receiver 216.

The second receiver 218 may include alternating phases in the circumferential direction. For example, receiver structure 720 has a first phase. Receiver structure 716 has a second phase. Thus, the phase of the second receiver 218 varies along the circumference of the second receiver 218. Furthermore, the phase of the second receiver 218 may vary continuously for at least a portion of the radial direction of the second receiver 218.

In Figure 7, the plurality of receiver structures 702 are not shown as continuous repetition around the entire circumference of the first receiver 216. Similarly, the plurality of receiver structures 704 are not shown as continuous repetition around the entire circumference of the second receiver 218. Those skilled in the art will understand using the disclosure provided herein that the plurality of receiver structures 702 may be continuous repetition around the entire 360° circumference of the first receiver 216. Similarly, the plurality of receiver structures 704 may be continuous repetition around the entire 360° circumference of the first receiver 218.

Figure 8 depicts a plan view of a plurality of rotor targets according to various aspects of this disclosure. Figure 8 illustrates an example of geometric decoupling between a first rotor target 212 and a second rotor target 214. As shown, a plurality of target convex angles 802 in the first rotor target 212 are orthogonal to a plurality of target convex angles 804 in the second rotor target 214 (the plurality of target convex angles 802 are rotated 90° relative to the plurality of target convex angles 804). By configuring the plurality of target convex angles 802 to be orthogonal to the plurality of target convex angles 804, interference between different channels of the torque sensor can be reduced.

In some embodiments, the plurality of target convex corners 802 in the first rotor target 212 and the plurality of target convex corners 804 in the second rotor target 214 do not overlap. In some embodiments, the plurality of target convex corners 802 in the first rotor target 212 and the plurality of target convex corners 804 in the second rotor target 214 have a cumulative overlap of less than 120° around the circumference, for example, a cumulative overlap of less than 90° around the circumference, for example, a cumulative overlap of less than 30° around the circumference, for example, a cumulative overlap of less than 15° around the circumference, for example, a cumulative overlap of less than 10° around the circumference, for example, a cumulative overlap of less than 5° around the circumference. As used herein, cumulative overlap refers to the total value of the circumferential overlap between target structures, regardless of whether the overlap is continuous or discontinuous.

As shown in Figure 8, the plurality of target convex angles 802 of the first rotor target 212 may include a first group of target convex angles and a second group of target convex angles spaced approximately 180° apart. Similarly, the plurality of target convex angles 804 of the second rotor target 214 may include a first group of target convex angles and a second group of target convex angles spaced approximately 180° apart.

Figure 9 depicts a plan view of a plurality of rotor targets according to various aspects of the present disclosure, these rotor targets having corresponding resonant and non-resonant circuits. Figure 9 shows a plurality of rotor targets including a first rotor target 212 and a second rotor target 214. The first rotor target 212 and/or the second rotor target 214 may be constructed of solid metal or a closed loop formed by conductive printed lines. In this example, the first rotor target 212 is a non-resonant target, and the second rotor target 214 is a resonant target. Furthermore, the second rotor target 214 may include a resonant circuit 906, which includes an inductor and/or a capacitor. In some embodiments, the first rotor target 212 (which may be non-resonant) can be converted into a resonant target by adding a capacitor, such that the first rotor target 212 has a resonant frequency approximately equal to the frequency of the driving frequency of the transmitting coil.

The time-varying magnetic field generated by the first rotor target 212 (e.g., a non-resonant rotor target) can be phase-shifted relative to the time-varying magnetic field generated by the second rotor target 214 (e.g., a resonant rotor target). Furthermore, the time-varying magnetic field of the first rotor target 212 can be phase-shifted by approximately 90° relative to the time-varying magnetic field generated by the second rotor target 214.

In some embodiments, the number of second receiver structures M of the second receiver is determined based on the number N of the first receiver structures, such that M = 2N ± 1.

Although the subject matter has been described in detail with reference to specific exemplary embodiments, it will be understood that those skilled in the art, upon gaining an understanding of the foregoing, will readily make changes, modifications, and equivalents to these embodiments. Therefore, the scope of this disclosure is by way of example rather than limitation, and this disclosure does not exclude such modifications, variations, and/or additions to the subject matter that would be obvious to those skilled in the art.

Claims (17)

1. A torque sensor, comprising: At least one excitation coil; At least one oscillating circuit coupled to the at least one excitation coil, wherein the oscillating circuit is configured to generate a periodic voltage signal and use the periodic voltage signal to provide power to the excitation coil; The first channel, comprising: A first receiver, comprising a plurality of periodically repeating first receiver structures, wherein the phase of the structure of the first receiver varies circumferentially along the first receiver and remains constant radially along the first receiver; A first rotor target, configured to couple to a first rotor, configured to influence the strength of the inductive coupling between the excitation coil and the first receiver; The second channel includes: The second receiver includes a plurality of periodically repeating second receiver structures, wherein the phase of the structure of the second receiver varies along the circumferential and radial directions of the second receiver; A second rotor target, configured to couple to a second rotor, and configured to influence the strength of the inductive coupling between the excitation coil and the second receiver; and The processing circuit is configured to provide a first signal associated with the first channel, the first signal indicating the position of the first rotor target relative to the first receiver, and the processing circuit is configured to provide a second signal associated with the second channel, the second signal indicating the position of the second rotor target relative to the second receiver; The torque sensor can reduce the electromagnetic coupling between the first channel and the second channel. 2. The torque sensor according to claim 1, wherein M is the number of the plurality of second receiver structures, N is the number of the plurality of first receiver structures, and M = 2N ± 1. 3. The torque sensor according to claim 2, wherein the first rotor target has a plurality of periodically repeating target convex angles, each target convex angle having an angle width, wherein the angle width of each target convex angle in the first rotor target is equal to the angle width corresponding to a single period of the plurality of second receiver structures in the second receiver. 4. The torque sensor according to claim 1, wherein the radial structural phase shift of the second receiver occurs at a specific point along the radial direction of the second receiver. 5. The torque sensor according to claim 4, wherein the phase shift of the structure is 180°. 6. The torque sensor according to claim 4, wherein the structural phase of the second rotor target varies along the circumferential and radial directions of the second rotor target in a manner corresponding to the second receiver. 7. The torque sensor of claim 6, wherein the first portion of the second rotor target comprises a conductive material, and the second portion of the second rotor target comprises a magnetic and non-conductive material. 8. The torque sensor according to claim 1, wherein the structural phase of the first rotor target varies circumferentially along the first rotor target in a manner corresponding to the first receiver, and remains constant radially along the first rotor target. 9. The torque sensor according to claim 1, wherein the structural phase of the second receiver changes continuously along at least a portion of the radial direction of the second receiver. 10. The torque sensor according to claim 9, wherein the structural phase of the first receiver changes continuously along at least a portion of the radial direction of the first receiver. 11. The torque sensor of claim 10, wherein the first receiver and the second receiver have radial structural phase changes having equal magnitudes but opposite directions relative to each other. 12. The torque sensor according to claim 1, wherein the time-varying magnetic field generated by the first rotor target is phase-shifted relative to the time-varying magnetic field generated by the second rotor target. 13. The torque sensor of claim 12, wherein the time-varying magnetic field generated by the first rotor target is phase-shifted by 90° relative to the time-varying magnetic field generated by the second rotor target. 14. The torque sensor of claim 12, wherein the second rotor target includes a resonant circuit having an inductance and a capacitance. 15. The torque sensor of claim 1, wherein the plurality of target convex angles do not repeat continuously around the entire circumference of the second receiver. 16. The torque sensor according to claim 15, wherein the plurality of target convex angles in the first rotor target and the plurality of target convex angles in the second rotor target have a cumulative overlap of less than 120°. 17. The torque sensor according to claim 15, wherein the plurality of target convex angles includes a first group of target convex angles and a second group of target convex angles, the first group of target convex angles being located at a position 180° away from the second group of target convex angles.