COMMUNICATIONS SYSTEM OF A VEHICLE

Abstract

A communications system of a vehicle that enables the vehicle to communicate with a portable ID transmitter of an operator, which is configured for UWB communication, e.g., via a UWB transceiver, includes at least one first UWB receiver with a first UWB antenna and a second UWB receiver with a second UWB antenna. The first UWB antenna and the second UWB antenna are arranged in a spaced apart manner from one another on the vehicle. The communications system is designed to evaluate UWB signals of the ID transmitter via a central UWB control unit or a central control device.

Claims

1. Communications system of a vehicle for the communication of the vehicle with a portable ID transmitter, which is configured for UWB communication, for enabling vehicle functions for an operator who carries the portable ID transmitter, wherein the communications system includes at least a first UWB receiver having a first UWB antenna and a second UWB receiver having a second UWB antenna, wherein the first UWB antenna and the second UWB antenna are arranged at a distance from one another on the vehicle, wherein a central UWB control unit of the vehicle is coupled to the first UWB receiver and to the second UWB receiver, wherein the central UWB control unit is configured to evaluate both a first reception signal of an ID transmitter UWB signal received by the first UWB antenna and a second reception signal of the same ID transmitter UWB signal received by the second UWB antenna as a function of one another for an authentication of the communication of the vehicle with the ID transmitter.

2. Communications system according to claim 1, wherein the direction of a maximum reception sensitivity of the first UWB antenna and the direction of a maximum reception sensitivity of the second UWB antenna are oriented at an angle to one another which angle is at least 30 degrees.

3. Communications system according to claim 1, wherein the direction of a maximum reception sensitivity of the first UWB antenna and the direction of a maximum reception sensitivity of the second UWB antenna are oriented at an angle to one another which angle is at most 120 degrees.

4. Communications system according to claim 1, wherein there is an overlap space in front of a driver's door of the vehicle, within which a reception sensitivity of the first UWB antenna and a reception sensitivity of the second UWB antenna exceed a minimum value at each location, whereby an extension of the overlap space, the selection, positioning and orientation of the UWB antennas as well as the selection of a UWB communication arrangement of the ID transmitter are adapted to one another in such a way that for the ID transmitter, UWB communication of the ID transmitter with the vehicle via both the first UWB antenna and the second UWB antenna can be carried out at least when the ID transmitter is positioned within the overlap space.

5. Communications system according to claim 1, wherein the UWB control unit is configured to evaluate a first runtime value of the first reception signal and a second runtime value of the second reception signal by means of N-lateration.

6. Communications system according to claim 1, wherein the UWB control unit is configured to determine a first runtime value of the first reception signal and a second runtime value of the second reception signal, wherein the communication between the ID transmitter and the vehicle is rejected as non-authentic communication if a runtime difference between the first runtime value and the second runtime value exceeds a maximum runtime by more than a tolerated deviation, the maximum runtime being the time required for traveling of the distance between the first UWB antenna and the second UWB antenna.

7. Communications system according to claim 1, wherein the UWB control unit is configured, to determine a runtime value for each of the detected reception signals and to calculate a mean runtime value from the determined runtime value, and/or to determine a signal strength value for each of the detected reception signals and to calculate a mean signal strength value from the determined signal strength values, wherein a mean UWB distance value is derived from the mean runtime value and/or the mean signal strength value, wherein an LF distance value is determined from a signal strength of a detected LF signal of the ID transmitter, the communication between the ID transmitter and the vehicle being rejected as non-authentic communication, if the LF distance value and the mean UWB distance value deviate from one another beyond a tolerated maximum deviation.

8. Communications system according to claim 7, wherein the tolerated maximum deviation is less than 30 percent, of the calculated mean UWB distance value.

9. Communications system according to claim 1, wherein the UWB control unit is configured to reject the communication between the ID transmitter and the vehicle as non-authentic communication, if only one of the UWB antennas detects a reception signal of the ID transmitter UWB signal.

10. Communications system according to claim 1, wherein the first UWB antenna is arranged in a first handle on a driver's door of the vehicle and/or the second UWB antenna is arranged in a second handle on a passenger door of the vehicle.

11. Communications system according to claim 1, wherein at least three spaced-apart UWB antennas are arranged on the vehicle.

12. Communications system according to claim 10, wherein four spaced-apart UWB antennas are arranged on the vehicle, the directions of maximum reception sensitivity being selected to be oriented perpendicular to one another and to be parallel to a driving plane of the vehicle.

13. Communications system according to claim 8 wherein the tolerated maximum deviation is less than 10 percent of the calculated mean UWB distance value.

14. Communications system according to claim 11 wherein at least four spaced-apart UWB antennas are arranged on the vehicle.

Description

[0066] In the drawings:

[0067] FIG. 1: A schematic diagram of a communications system according to the invention;

[0068] FIG. 2: Another schematic diagram of the communications system according to the invention from FIG. 1.

[0069] FIG. 1 shows an exemplary embodiment of a communications system 1. The individual structural components of the communications system 1 are arranged on a vehicle 2. With the communications system 1, the vehicle 2 is at least enabled for UWB communication with a portable ID transmitter 3. UWB communication is used, for example, to activate vehicle functions for an operator 4 who carries the ID transmitter 3 with him. The ID transmitter 3 is portable, i.e. can be carried by the operator 4 without any aids. The ID transmitter 3 is also configured for UWB communication. The ID transmitter 3 thus has communication means which enable the ID transmitter 3, among other things, for UWB communication. For example, these communication means can be a UWB transceiver 5 that has a UWB antenna. The ID transmitter 3 is not part of the communications system 1 of the present invention. However, the ID transmitter 3 and the communications system 1 are configured for UWB communication with one another, that is to say that all the necessary hardware and software requirements are provided such that the operator 4 can be authenticated by means of the ID transmitter 3 by using UWB communication between the ID transmitter 3 and communications system 1 on the vehicle as being authorized to grant functionality.

[0070] The communications system 1 has a first UWB receiver 6, which is coupled to a first UWB antenna 7. Furthermore, a second UWB receiver 6′ having a second UWB antenna 7′ and two further UWB receivers 6″, 6′″ each having a further UWB antenna 7″, 7′″ are arranged on the vehicle. The UWB antennas 7, 7′, 7″, 7′″ are arranged on the vehicle 2 at a distance from one another. In particular, the first UWB antenna 7 in the embodiment shown is arranged in a first handle on a driver's door 8 and the third UWB antenna 7″ is arranged in a second handle on a passenger's door 9. The handles are not shown due to the schematic representation.

[0071] The UWB receivers 6, 6′, 6″, 6′″ are coupled to a central UWB control unit 10 of the vehicle 2, the coupling being wired in the example shown. In the embodiment shown, the central UWB control unit 10 of the vehicle 2 is part of a central control unit 11 of the vehicle 2. However, it is also conceivable that the UWB control unit 10 is designed as a separate unit from the central control unit 11.

[0072] When the operator 4 approaches the vehicle, authentication of operator 4 is carried out as a prerequisite for enabling functions of vehicle 2 for the operator 4. This is initially done, for example, according to a procedure known from practice. Such a known method sequence provides, for example, that a low-frequency LF wake-up signal is first emitted by the vehicle 2. The LF wake-up signal switches the ID transmitter 3, which is prepared for receiving LF wake-up signals, from an energy-saving mode into an active mode. In response to the LF wake-up signal, the ID transmitter 3 initiates UWB communication with the vehicle-side control unit 11. The UWB communication takes place by means of the UWB transceiver 5 of the ID transmitter 3. In the course of the UWB communication between the ID transmitter 3 and the motor vehicle control unit 11, for example, there is a mutual exchange of encrypted information and its verification by the other communication partner involved. Alternatively, it is of course also conceivable that the UWB communication is initiated by the vehicle-side central control unit 11 or by the UWB control unit 10 in response to an LF or HF request from the ID transmitter.

[0073] During UWB communication, the ID transmitter 3 sends out an ID transmitter UWB signal 12. In many cases, the ID transmitter UWB signal 12 is the response to a vehicle UWB signal. Both the first UWB antenna 7, which is coupled to the first UWB receiver 6, and the second UWB antenna 7′, which is coupled to the second UWB receiver 6′, receive the ID transmitter UWB signal 12. The first reception signal of the ID transmitter UWB signal 12 received by the first UWB receiver 6 and the second reception signal of the ID transmitter UWB signal 12 received by the second UWB receiver 6′ are transmitted to the central UWB control unit 10. The central UWB control unit evaluates both signals together for plausibility.

[0074] FIG. 2 shows the limit lines of the reception capability of the first UWB antenna 13, the second UWB antenna 13′, the third UWB antenna 13″, and the fourth UWB antenna 13′″. Outside the illustrated border lines, UWB communication of the specific ID transmitter 3 with the specific UWB antenna is no longer possible; the course of the border lines is therefore always dependent on the specific design of the individual components of the communications system 1 and the ID transmitter, whereby the communications system is configured for use with an appropriately suitable ID transmitter. The point of reception capability furthest from the UWB antenna defines the direction of maximum reception sensitivity based on the respective UWB antenna. These directions are symbolized by the arrows 14, 14′, 14″, 14′″. It can be seen that the UWB antennas 7, 7′, 7″, 7′″ have a pronounced directional characteristic, the direction of the maximum reception sensitivity in the exemplary embodiment shown being an axis of symmetry of a main lobe of the respective UWB antenna 7, 7′, 7″, 7′″. In the embodiment shown, the directions of the maximum reception sensitivity of two adjacent UWB antennas are oriented perpendicular to one another as a result of the selection of the UWB antennas, the orientation of the UWB antennas, and their positioning on the vehicle.

[0075] It can also be seen that two adjacent UWB antennas each provide an overlap space in the embodiment shown. For example, the regions with a minimum reception sensitivity of the first antenna 7 and the second antenna 7′ form an overlap space 15 within which both the first UWB antenna 7 and the second UWB antenna 7′ can receive a transmitted UWB signal from the ID transmitter 3. In other words, due to the selection, positioning, and orientation of the UWB antennas and the selection of a UWB communication arrangement of the ID transmitter within the overlap space 15, UWB communication of the ID transmitter 3 with the vehicle 2 is both possible via the first UWB antenna 7 and also via the second UWB antenna 7′. Of course, the selection, positioning, and orientation of the antennas can be modified by the person skilled in the art, for example orientations, selection, and positioning can also be provided in which overlap spaces exist within which communication with all available UWB antennas is possible. In accordance with the above explanations, the specific dimensioning of the overlap space thus depends both on the specific type and positioning of the UWB antennas and on the selection of the ID transmitter. However, since the authorized ID transmitter 3 must be known to the vehicle 2 anyway, the person skilled in the art can select and position and control the UWB antennas with knowledge of one or more types of ID transmitters without this being particularly difficult for him.

[0076] Because UWB communication of the ID transmitter 3 within the overlap space 15 is possible both with the first UWB antenna 7 and with the second UWB antenna 7′, the central UWB control unit 10 is provided with both a first reception signal of the ID transmitter UWB signal 12 and a second reception signal of the ID transmitter UWB signal 12. The central UWB control unit 10 is thereby enabled to evaluate the authenticity of the received ID transmitter UWB signal 12 according to its configuration and to take into account both the first and the second reception signal of the same ID transmitter UWB signal 12 in the evaluation.

[0077] In the embodiment shown, the overlap space 15 is adapted by the person skilled in the art to provide the object according to the invention in such a way that the communication of the ID transmitter UWB signal with the first UWB antenna 7 and the second UWB antenna 7′ is possible at one position of the operator 4, which he assumes when he approaches the driver's door 8. A narrowly defined limitation of the overlap space 15 is not important as long as it is ensured that, in the course of the operating behavior provided by the developers, an ID transmitter UWB signal transmitted by the ID transmitter 3 is received with a sufficient signal strength for communication and for signal evaluation both on the first UWB antenna 7 and on the second UWB antenna 7′. This ensures that with a natural operating behavior of the operator 4, the specifications of the central UWB control unit 10 configured according to the invention can be implemented by the latter.

[0078] In particular, in the embodiment shown it is provided that communication of the vehicle 2 with the ID transmitter 3 is rejected as non-authentic communication if a runtime difference of a runtime value of the UWB signal on route S1 and the UWB signal on route S2 is greater than a runtime value corresponding to the distance between the first antenna 7 and the second antenna 7′, S3. In this case it can be concluded that at least one of the UWB signals has traveled a different route than the route S1 or the route S2 or that one of the signals could have been manipulated.

[0079] A communications system 1 of a vehicle 2 is therefore shown in a preferred embodiment, the preferred embodiment having four UWB antennas 7, 7′, 7″, 7′″ spaced apart from one another, whose directions of maximum reception sensitivity are selected to be oriented perpendicularly to one another and lying in parallel to a driving plane of the vehicle 2. Two adjacent UWB antennas form an overlap space, the respective overlap space ensuring that an ID transmitter 3 located near the vehicle can carry out UWB communication with the vehicle 2 via at least two of the UWB antennas of the vehicle 2. This ensures that improved security is achieved before an authentication of the ID transmitter 3 is compromised.

[0080] For a specific embodiment, the person skilled in the art entrusted with the implementation offers many methods for implementing the communications system according to the invention. In particular, by means of targeted selection of the antennas, targeted arrangement of the antennas on the vehicle, and reception characteristics of the individual UWB antennas that are optimized for desired applications, environmental spaces designated according to the invention as overlap spaces can be provided, within which an ID transmitter UWB signal of two or more than two UWB antennas is received.

[0081] Various methods for testing the authenticity of the communication of the vehicle 2 with the ID transmitter 3 can be implemented to validate the reception signal, wherein, depending on the security requirements, the simultaneous fulfillment of a plurality of conditions can serve as a prerequisite for enabling vehicle functions.