Method for controlling access to a motor vehicle

1. A method for operating a passive access system for motor vehicles,

wherein on an associated motor vehicle, multiple vehicle-side transmission antennas are arranged on different spatial positions for sending out low frequency signals, which are coupled to at least one control device,

wherein the control device is coupled to vehicle-side transmission-reception means for wireless communication,

wherein a mobile ID transponder with respect to the associated motor vehicle is formed by a 3D-receiving antenna assembly for receiving low frequency signals,

wherein the ID transponder has key-side transmission-reception means for a wireless communication,

wherein by means of the control device, a first vehicle-side transmission antenna and a second vehicle-side transmission antenna are controlled for time-delayed sending out first time-delayed low frequency signals with respectively arranged transmission signal strengths,

wherein by means of the control device, the first- and the second vehicle-side transmission antenna are controlled for simultaneously sending out the first simultaneous low frequency signals with respectively arranged transmission signal strengths,

wherein in the mobile ID transponder, at least one of the time-delayed or simultaneous low frequency signals is received by means of 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is carried out, so that for each of the spatial directions of the 3D receiving antenna assembly, space-direction-dependent signal strength information is determined,

wherein information related to the space-direction-dependent signal strengths of the ID transponder is transmitted wirelessly from the key-side transmission-reception means to the vehicle-side transmission-reception means of the control device,

wherein the control device receives information related to the space-direction-dependent signal strengths and, depending on the received information, controls one or more vehicle-side transmission antennas for sending out time-delayed or simultaneously other low frequency signals,

wherein the respectively assigned transmission-signal strengths are selected depending on the received information related to the space-direction-dependent signal strengths,

wherein in the mobile ID transponder, further low frequency signals are received by means of the 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is performed, so that for each of the spatial direction of the 3D antenna assembly, further space-direction-dependent signal strength information is determined,

wherein depending on further spatial direction-dependent signal strength information, a plausibility check is carried out, which checks whether the space-direction-dependent signal strength information is consistent, in order to detect an extension of the signal path between the associated motor vehicle and the ID transponder via intermediate stations,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes another vehicle-side transmission antenna, instead of the vehicle-side transmission antenna associated with the signal, to be controlled for sending another signal.

2. The method according to claim 1 , wherein in the signals sent from the vehicle-side transmission antenna, a unique identifier of the respective transmitting transmission antennas is coded.

3. The method according to claim 1 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein, then when the signal strength evaluation indicates an override in at least one of the spatial directions of the 3D antenna assembly, the information related to the spatial direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be reduced.

4. The method according to claim 1 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be increased.

5. The method according to claim 1 ,

wherein in the mobile ID transponder, at least one of the first simultaneous low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased or reduced.

6. The method according to claim 5 , wherein then when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased and the transmission power of another one of the associated vehicle-side transmission antennas to be reduced.

7. The method according to claim 1 ,

wherein the vehicle-side transmission antennas for sending out further low frequency signals are controlled in such a way that at least two vehicle-side transmission antennas are simultaneously controlled,

wherein time-dependently, the transmission antennas are controlled with mutually changed signal strengths, in such a way that in the ID transponder, the superimposed-received signals have time-dependently different field vectors, wherein depending on a time-dependent change of the field vectors, a plausibility check is performed.

8. A method for operating a passive access system for motor vehicles,

wherein on an associated motor vehicle, multiple vehicle-side transmission antennas are arranged on different spatial positions for sending out low frequency signals, which are coupled to at least one control device,

wherein the control device is coupled to vehicle-side transmission-reception means for wireless communication,

wherein a mobile ID transponder with respect to the associated motor vehicle is formed by a 3D-receiving antenna assembly for receiving low frequency signals,

wherein the ID transponder has key-side transmission-reception means for a wireless communication,

wherein by means of the control device, a first vehicle-side transmission antenna and a second vehicle-side transmission antenna are controlled for time-delayed sending out first time-delayed low frequency signals with respectively arranged transmission signal strengths,

wherein by means of the control device, the first- and the second vehicle-side transmission antenna are controlled for simultaneously sending out the first simultaneous low frequency signals with respectively arranged transmission signal strengths,

wherein in the mobile ID transponder, at least one of the time-delayed or simultaneous low frequency signals is received by means of 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is carried out, so that for each of the spatial directions of the 3D receiving antenna assembly, space-direction-dependent signal strength information is determined,

wherein information related to the space-direction-dependent signal strengths of the ID transponder is transmitted wirelessly from the key-side transmission-reception means to the vehicle-side transmission-reception means of the control device,

wherein the control device receives information related to the space-direction-dependent signal strengths and, depending on the received information, controls one or more vehicle-side transmission antennas for sending out time-delayed or simultaneously other low frequency signals,

wherein the respectively assigned transmission-signal strengths are selected depending on the received information related to the space-direction-dependent signal strengths,

wherein in the mobile ID transponder, further low frequency signals are received by means of the 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is performed, so that for each of the spatial direction of the 3D antenna assembly, further space-direction-dependent signal strength information is determined,

wherein depending on further spatial direction-dependent signal strength information, a plausibility check is carried out, which checks whether the space-direction-dependent signal strength information is consistent, in order to detect an extension of the signal path between the associated motor vehicle and the ID transponder via intermediate stations,

wherein in the mobile ID transponder, only one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein the information related to the space-direction-dependent signal strengths in the control device causes another vehicle-side transmission antenna, instead of the vehicle-side transmission antenna, which has not sent the signal received in the ID transponder, to be controlled for sending another signal.

9. The method according to claim 8 , wherein in the signals sent from the vehicle-side transmission antenna, a unique identifier of the respective transmitting transmission antennas is coded.

10. The method according to claim 8 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein, then when the signal strength evaluation indicates an override in at least one of the spatial directions of the 3D antenna assembly, the information related to the spatial direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be reduced.

11. The method according to claim 8 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be increased.

12. The method according to claim 8 ,

wherein in the mobile ID transponder, at least one of the first simultaneous low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased or reduced.

13. The method according to claim 12 , wherein then when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased and the transmission power of another one of the associated vehicle-side transmission antennas to be reduced.

14. The method according to claim 8 ,

wherein the vehicle-side transmission antennas for sending out further low frequency signals are controlled in such a way that at least two vehicle-side transmission antennas are simultaneously controlled,

wherein time-dependently, the transmission antennas are controlled with mutually changed signal strengths, in such a way that in the ID transponder, the superimposed-received signals have time-dependently different field vectors, wherein depending on a time-dependent change of the field vectors, a plausibility check is performed.

15. A method for operating a passive access system for motor vehicles,

wherein on an associated motor vehicle, multiple vehicle-side transmission antennas are arranged on different spatial positions for sending out low frequency signals, which are coupled to at least one control device,

wherein the control device is coupled to vehicle-side transmission-reception means for wireless communication,

wherein a mobile ID transponder with respect to the associated motor vehicle is formed by a 3D-receiving antenna assembly for receiving low frequency signals,

wherein the ID transponder has key-side transmission-reception means for a wireless communication,

wherein by means of the control device, a first vehicle-side transmission antenna and a second vehicle-side transmission antenna are controlled for time-delayed sending out first time-delayed low frequency signals with respectively arranged transmission signal strengths,

wherein by means of the control device, the first- and the second vehicle-side transmission antenna are controlled for simultaneously sending out the first simultaneous low frequency signals with respectively arranged transmission signal strengths,

wherein in the mobile ID transponder, at least one of the time-delayed or simultaneous low frequency signals is received by means of 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is carried out, so that for each of the spatial directions of the 3D receiving antenna assembly, space-direction-dependent signal strength information is determined,

wherein information related to the space-direction-dependent signal strengths of the ID transponder is transmitted wirelessly from the key-side transmission-reception means to the vehicle-side transmission-reception means of the control device,

wherein the control device receives information related to the space-direction-dependent signal strengths and, depending on the received information, controls one or more vehicle-side transmission antennas for sending out time-delayed or simultaneously other low frequency signals,

wherein the respectively assigned transmission-signal strengths are selected depending on the received information related to the space-direction-dependent signal strengths,

wherein in the mobile ID transponder, further low frequency signals are received by means of the 3D antenna assembly, and for each of the spatial directions, a signal strength evaluation is performed, so that for each of the spatial direction of the 3D antenna assembly, further space-direction-dependent signal strength information is determined,

wherein depending on further spatial direction-dependent signal strength information, a plausibility check is carried out, which checks whether the space-direction-dependent signal strength information is consistent, in order to detect an extension of the signal path between the associated motor vehicle and the ID transponder via intermediate stations,

wherein in the mobile ID transponder, at least one of the first simultaneous low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes another vehicle-side transmission antenna, instead of one of the associated vehicle-side transmission antennas, to be controlled for sending another signal.

16. The method according to claim 15 , wherein in the signals sent from the vehicle-side transmission antenna, a unique identifier of the respective transmitting transmission antennas is coded.

17. The method according to claim 15 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein, then when the signal strength evaluation indicates an override in at least one of the spatial directions of the 3D antenna assembly, the information related to the spatial direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be reduced.

18. The method according to claim 15 ,

wherein in the mobile ID transponder, at least one of the first time-delayed low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of the associated vehicle-side transmission antenna to be increased.

19. The method according to claim 15 ,

wherein in the mobile ID transponder, at least one of the first simultaneous low frequency signals is received by means of the 3D antenna assembly, and

wherein then, when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased or reduced.

20. The method according to claim 19 , wherein then when the signal strength evaluation indicates a signal strength below a predetermined threshold in at least one of the spatial directions of the 3D antenna assembly, the information related to the space-direction-dependent signal strengths in the control device causes the transmission power of at least one of the associated vehicle-side transmission antennas to be increased and the transmission power of another one of the associated vehicle-side transmission antennas to be reduced.

21. The method according to claim 15 ,

wherein the vehicle-side transmission antennas for sending out further low frequency signals are controlled in such a way that at least two vehicle-side transmission antennas are simultaneously controlled,

wherein time-dependently, the transmission antennas are controlled with mutually changed signal strengths, in such a way that in the ID transponder, the superimposed-received signals have time-dependently different field vectors, wherein depending on a time-dependent change of the field vectors, a plausibility check is performed.