JP2008160801A - Access control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an access control system for wheeled vehicle, or the like. <P>SOLUTION: The access control system 10, specifically for a wheeled vehicle, has an accessor's electronic control device 14, a user's identification device 12, and means 16, 18 for wireless bi-directional communication between the accessor's control device 14 and user's identification device 12. At least one activation signal produced by the control device 14 is sent to the identification device 12 to activate the identification device 12 in a first operation mode, and information is exchanged between the control device 14 and the identification device 12, in a second operation mode with the identification device 12 activated. In the first operation mode, the activation signal produced by the control device 14 is sent, at least one ultra-high frequency (UHF), to the identification device 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an access control system for a vehicle in particular, and relates to an electronic control device disposed on an access side, an identification device disposed on a user side, and between an access side control device and a user side identification device. And at least one activation signal generated by the control device is sent to the identification device in a first operating mode to activate the identification device, and the identification device is activated second The present invention relates to an access control system in which information is exchanged between a control device and an identification device in the mode.

  An access control system of the above type is used when checking whether each person as a carrier of each identification device is authorized to pass each access control device. This may be true for both stationary access control devices that are accessed only by a selected range of people, as well as portable access control devices provided especially in vehicles such as cars, boats or bicycles. Each vehicle theft should in particular be intercepted by each access control device.

  Each access control system can be provided as a so-called keyless ride system and / or a keyless vehicle starting system. In this case, the access control system is associated with a vehicle and is generally an electronic control device that is permanently supplied with energy, and a portable identification device that is intended to identify each authorized user. And. Each identification device may itself be part of a vehicle key, the identification device being able to exchange data, preferably both, with the control device located in the area of the vehicle locking and / or starting system. Data exchange is performed. Each identification device may in particular be integrated into a chip card or the like, for example, made as a transponder. Transponders do not have their own energy supply. The transponder is energized in a wireless manner when the identification device approaches the control device and is automatically addressed in a further process for transmitting a proof response signal.

  The use of two-way wireless communication between the vehicle and the identification device is typical for a keyless ride control system. For previously customary systems, LF (eg, 20 kHz, 125 kHz, 13.56 MHz) is provided to activate the identification device and to identify the location (inside or outside) of this identification device. ing. The use of UHF systems (eg, 315 MHz, 433 MHz, 868 MHz, 2.45 GHz) takes advantage of the higher data rate compared to LF data communication, saving communication time and thus increasing the useful life of the battery For communication and data exchange between the vehicle and the electronic identification device.

  Ferrite core antennas are used inside door handles or doors in previous customary systems to establish a connection between the vehicle and the identification device. In this context, each antenna must be tuned to and connected to the electronic central unit. This is a very complex mechanism and is expensive. This is because no more than 10 ferrite core antennas are required to protect a keyless system to full effectiveness.

  The object underlying the present invention is to improve an access control system of the kind mentioned at the outset which solves the aforementioned problems. In particular, the design should be simplified and costs should be reduced accordingly.

The above problem is fulfilled according to the present invention and the activation signal generated by the control device in the first operating mode is sent to the identification device via at least one UHF frequency.
The access control system is substantially simple in design and thereby results from this more cost effective configuration. In view of the UHF (ultra high frequency) provided for activation of the identification device for the first mode of operation, the previously required LF antenna can be omitted. In view of the distance field situation in the UHF mode, the activation channel of the identification device is independent of the arrangement or position of the identification device. In contrast, a conventional pure LF activated injector system requires an all-three-dimensional activated receiver circuit due to near-field behavior at low frequencies.

The LF carrier modulated with the activation signal is preferably mixed with the UHF frequency, and the resulting mixed signal is sent to the identification device.
In the above background, an ASK modulation carrier, a PSK modulation carrier or an FSK modulation carrier (ASK = amplitude shift key verification, PSK = phase shift key verification, FSK = frequency shift key verification) can be used as the LF carrier.

  Suitably, the identification device obtains filter means and demodulation means for filtering and demodulating the received mixed signal, and LF carrier information (LF = low frequency) obtained by filtering and demodulating the mixed signal. However, an LF activation receiving unit is provided. The filter means and the demodulation means are preferably passive elements, i.e. non-battery operated components.

  The demodulating means can comprise, for example, at least one electric LF resonance circuit. Such an electric LF resonance circuit can include, for example, an inductance and a capacitor arranged in parallel thereto.

  In an access control system according to a preferred practical embodiment of the invention, the information exchange between the control device and the identification device in the second operating mode is at least partly performed via at least one UHF frequency. In this context, in particular, the total exchange of information between the control device and the identification device can also take place via at least one UHF frequency.

  As an alternative to the above, in the second operating mode, the information exchange between the control device and the identification device may be performed at least partly via at least one LF frequency. Thus, at least in this case, the identification device can also comprise both high and low frequency antenna receivers. In general, in this second mode of operation, the total exchange of information between the control device and the identification device is considered to take place via at least one LF frequency.

  Thus, if only the UFH connection is used, the LF antenna previously required in the vehicle can be omitted. The demodulated signal of UHF connection enables the activation of the identification device on the user side. When the identification device is activated, data exchange can occur in the UHF frequency band so that higher data rates can be achieved. However, the exchange of data can occur in the same manner as the activation of the identification device.

  For example, an LF carrier with ASK modulation, PSK modulation or FSK modulation may be able to transmit a connection establishment signal emitted from a vehicle or an electronic control system or a base station associated with the system to an identification device. , Must be mixed with the UHF frequency. After receiving the connection establishment signal formed by the mixed signal, the RF information (RF = radio frequency) is filtered on the identification device side so that only the LF carrier information is applied to the LF section of the circuit of the identification device. It can be demodulated. The identification device may be provided with, for example, an LF resonance circuit including an inductance and a capacitor connected in parallel to the inductance device. The LF resonance circuit includes a logic unit of the identification device including at least one integration circuit. In order to be able to generate an activation signal from the modulated LF carrier sent from the control device and to ensure that the identification device has been switched to the activated state, the input of the LF receiver of the identification device Arranged on the side. For example, data exchange between the control device associated with the vehicle and the user-side identification device can occur via at least one UHF frequency in order to shorten the consumption time by increasing the data rate. However, each data exchange can also occur in the LF frequency band, as is known per se.

  Since the activation of the identification device occurs during the UHF connection, the activation channel of the LF receiver of the identification device is independent of the location or position of the identification device, which is actually a far field in this mode of operation. Due to the situation. This technique is fundamentally different from that of a pure LF activation system, and a three-dimensional activation receiver circuit is required as a result of near-field behavior at low frequencies, i.e. at large wavelengths.

  The invention will be explained in more detail in the following description with reference to examples and drawings shown in the examples.

  FIG. 1 shows, in a simplified schematic representation, an exemplary embodiment of an access control system 10 in a first mode of operation that functions for activation of the identification device 12. On the other hand, in FIG. 2, the access control system 10 is shown in the second operation mode in which information is exchanged with the activation identification device 12.

  In particular, an access control system 10 provided for a vehicle includes an electronic control device 14 provided on the access side, an identification device provided on the user side, a control device 14 on the access side, and an identification device 12 on the user side. And means with antennas 16, 18 for wireless two-way communication between them.

  In the first mode of operation shown in FIG. 1, at least one activation signal generated by the control device 14 is transmitted to the identification device 12 via the control device 14 or an antenna 16 associated with the vehicle for activation of the identification device 12. Is transmitted to. The identification device 12 receives this activation signal via the antenna 18 associated therewith. In the second mode of operation shown in FIG. 2, information is exchanged between the control device 14 and the activation identification device 12.

  In the above connection mode, in the first operation mode (for example, FIG. 1), the activation signal generated by the control device 14 is sent to the identification device 12 via at least one UHF frequency F2.

In this case, the LF carrier F <b> 1 modulated with the activation signal is mixed with the UHF frequency F <b> 2 using the mixer stage 20, and the obtained mixed signal F <b> 2 is sent to the identification device 12.
The ASK modulation carrier, the PSK modulation carrier, or the FSK modulation carrier can be provided as, for example, the LF carrier F1.

  The identification device 12 includes filter means 22 for filtering the received mixed signal F12 and demodulation means 24 for demodulation. Furthermore, the identification device 12 includes an LF activation receiving unit 26, and LF carrier information obtained by filtering and demodulating the mixed signal F12 is supplied to the receiving unit.

  The demodulating means 24 includes an electric LF resonance circuit 28. In this case, the electric LF resonance circuit 28 includes an inductance L1 and a capacitor C1 arranged in parallel with the inductance.

A passive demodulator such as a demodulator diode, preferably a Schottky diode 30, can be provided between the filter means 22 and the LF resonant circuit 28, for example.
In the second mode of operation (eg, FIG. 2), the exchange of information between the controller 14 and the identification device 12 can be performed, for example, via at least one UFH frequency F2. In particular, bidirectional exchange of information is possible.

  As can be appreciated with reference to FIG. 2, the identification device 12 comprises a filter means 22, a UHF receiver 32, a microcontroller 34, and a UHF transmitter 36 for this purpose. it can.

  The transmit and receive antennas 16 are associated with the controller 14 on the access side and / or the vehicle side, but generally an integrated transmit / receive antenna is also conceivable. Receiving and transmitting antennas 18 are also associated with the identification device 12, and again generally integrated transmitting / receiving antennas are also conceivable.

FIG. 1 is a simplified schematic representation of an example embodiment of an access control system in a first mode of operation that functions for activation of an identification device. FIG. 2 is a diagram of the access control system associated with FIG. 1 in a second mode of operation for exchanging information with the activation identification device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Access control system 12 Identification apparatus 14 Electronic control apparatus 16 Antenna 18 Antenna 20 Mixer stage 22 Filter means 24 Demodulation means 26 LF reception part 28 LF resonance circuit 30 Passive demodulation apparatus, Schottky diode 32 UHF reception part 34 Microcontroller 36 UHF transmission Part C1 Capacitor F1 Modulated LF carrier F2 UHF frequency F12 Mixed signal L1 Inductance

Claims (12)

In particular, an access control system (10) for a vehicle,
An electronic control device (14) provided on the access side;
An identification device (12) provided on the user side;
Means (16, 18) for wireless bi-directional communication between the control device (12) on the access side and the identification device (12) on the user side;
With
In the first operating mode, at least one activation signal generated by the control device (14) is sent to the identification device (12) to activate the identification device (12), and the identification device (12) is activated. Information is exchanged between the control device (12) and the identification device (12) in the second operating mode of
The access control system according to claim 1, characterized in that the activation signal generated by the control device (14) is sent to the identification device via at least one UHF frequency (F2) in the first operating mode.   The LF carrier (F1) modulated with the activation signal is mixed with the UHF frequency (F2) and the resulting mixed signal (F12) is sent to the identification device (12). The access control system described in.   Access control system according to claim 2, characterized in that an ASK modulated carrier is provided as the LF carrier (F1).   The access control system according to claim 2, characterized in that a PSK modulated carrier is provided as the LF carrier (F1).   Access control system according to claim 2, characterized in that an FSK modulated carrier is provided as the LF carrier (F1).   The identification device (12) includes a filter unit (22) for filtering the received mixed signal (F12), a demodulating unit (24) for demodulating the signal, and the mixed signal (F12). The access control system according to any one of claims 1 to 5, further comprising an LF activation reception unit (26) to which the LF carrier information obtained by filtering and demodulation is supplied.   The access control system according to claim 6, characterized in that the demodulation means comprise at least one electrical LF resonance circuit (28).   The access control system according to claim 7, characterized in that the electrical LF resonance circuit (28) comprises an inductance (L1) and a capacitor (C1) provided in parallel with the inductance.   The exchange of information between the control device (14) and the identification device (12) occurs at least partly via at least one UHF frequency (F2) in the second operating mode. The access control system according to any one of claims 1 to 8.   A total exchange of information between the control device (14) and the identification device (12) occurs via at least one UHF frequency (F2) in the second operating mode. Item 10. The access control system according to Item 9.   The exchange of information between the control device (14) and the identification device (12) occurs at least partly via at least one LF frequency in the second operating mode. Item 9. The access control system according to any one of Items 1 to 8.   12. The total exchange of information between the control device (14) and the identification device (12) occurs via at least one LF frequency in the second operating mode. The described access control system.

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