GB2569987A

GB2569987A - Vehicle access system

Info

Publication number: GB2569987A
Application number: GB1800232.9A
Authority: GB
Inventors: Bradley Andrew; Corne Hester
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2018-01-08
Filing date: 2018-01-08
Publication date: 2019-07-10
Anticipated expiration: 2038-01-08
Also published as: GB201800232D0; GB2569987B

Abstract

A control module 60 for controlling operation of a vehicle access system comprises a communications interface 62 for sending and receiving communications signals, the interface being configurable to communicate with two or more antennas 71-76; a processor 61 for controlling operation of the vehicle access system in dependence on communications signals received at the communications interfacefrom the two or more antennas. The processor configures the communications interface to connect to a first antenna 71 and to scan signals received from the first antenna for a notification signal from a communications device 80 over a communications channel and then configures the communications interface, in dependence on detecting the notification signal from the communications device at the first antenna, to connect to at least one second antenna 72-76; and further generates the control signal for the vehicle access system in dependence on further communications signals from the communications device received at the communications interface from the second antenna(s). The communications interface may be a BLUETOOTH (RTM) transceiver, particularly a BLUETOOTH (RTM) LOW ENERGY transceiver. The communications device may be identified and authorised based on its identity and a challenge-response process. Signal strength information may be used to locate the communications device.

Description

VEHICLE ACCESS SYSTEM

TECHNICAL FIELD

The present disclosure relates to a vehicle access system and particularly, but not exclusively, to a keyless access/entry system for a vehicle such as a motor vehicle. Aspects of the invention relate to a control module for controlling operation of a vehicle access system, to a vehicle access system, to a vehicle and to a method.

BACKGROUND

In existing keyless vehicle entry systems, also known as remote keyless entry or RKE systems, it is possible to gain access to a vehicle and enact one or more vehicle operations by interacting with an authorised keyless remote (a “key fob device”). Keyless remotes are activated, upon demand, by selectively pressing buttons on the keyless remote to command specific vehicle operations. Activating the keyless remote causes it to generate a radio wave command signal, containing a key code identifier, which is transmitted to a receiver unit in the vehicle. The receiver unit performs one or more vehicle operations in response to the command signal.

More recently, passive entry systems have been developed which make it possible to gain authorised access to a vehicle and start the vehicle without any interaction by the authorised user (or vehicle owner) with a key fob. In such passive entry systems, the vehicle user typically carries a key fob which can communicate with a base station in the vehicle. The key fob remains in a very low power state to conserve its internal battery. Upon receipt of an initiating trigger (for example when a vehicle door handle is operated), the base station emits a powerful Low Frequency (LF) electromagnetic field, the energy from which wakes up the key fob using a charge pump technique. Once awake, the key fob can then respond to a challenge using Radio Frequencies (RF). The key fob sends a response signal which is validated by the base station to authenticate the key fob. If the key fob is authenticated, the base station actuates a door lock to unlock the door.

The energy required from the vehicle to generate the LF field is considerable, which is why a trigger is employed to begin the process. Moreover, the consequence of using an initiating trigger is that the whole sequence of validating the key fob's identity and unlocking the vehicle has to be extremely short to avoid a customer experiencing a delay in the vehicle's response. To help avoid any such delay, a fast-release actuator can be provided to unlock the door to provide seamless operation as if the vehicle was already unlocked.

Modern vehicles may also offer functionality in which certain vehicle functions are deployed as the user approaches the vehicle, e.g. vehicle lighting units may be switched on and deployable handles may be moved from a retracted configuration to a deployed configuration. Such “approach functionality” requires the keyless entry system to work over larger distances so that the vehicle has sufficient time to deploy such functionality. As noted above, the energy involved in generating the required RF fields used to support communications between the vehicle and the key fob device is considerable and consequently battery life considerations may hamper the deployment of approach functionality.

It is an aim of the present invention to address disadvantages associated with the prior art.

SUMMARY OF THE INVENTION

According to an aspect of the present invention there is provided a control module for controlling operation of a vehicle access system, the control module comprising: a communications interface for sending and receiving communications signals, the interface being configurable to communicate with two or more antennas; a processor for controlling operation of the vehicle access system in dependence on communications signals received at the communications interface from the two or more antennas; and an output for outputting a control signal; wherein the processor is arranged to: configure the communications interface to connect to a first antenna and to scan signals received from the first antenna for a notification signal from a communications device over a communications channel; configure the communications interface, in dependence on detecting the notification signal from the communications device at the first antenna, to connect to a second antenna; and generate the control signal for the vehicle access system in dependence on further communications signals from the communications device received at the communications interface from the second antenna.

The control module may be incorporated within an electronic control unit within a vehicle or within a transceiver device (e.g. a Bluetooth transceiver).

The notification signal may comprise a general advertising/broadcast signal from the communications device advertising the presence of the communications device.

The control module according to the above aspect of the present invention provides a module having a communications interface that may be arranged to connect to two or more antennas. The control module may be configured to receive signals from a first antenna, e.g. located centrally within a vehicle, such that the control module can “listen” for an advertising signal (the “notification signal”) of the communication device to be detected. Upon detection of the notification signal the processor is arranged to connect the communications interface to a second antenna in order to receive further communications signals from the communications device (via the second antenna) and, in dependence on receiving such further signals, to generate a control signal for the vehicle access system. The second antenna may be located in a door handle, or be associated with the door handle of the vehicle. Switching the communications interface between antennas provides a power saving benefit and additionally switching from an antenna that may be centrally located to an antenna located at or associated with an access point of the vehicle enables a more accurate determination of proximity of the device to be made.

The processor may be arranged to identify the communications device. The processor may be arranged to compare a device identifier contained within the notification signal with a list or set of authorised communications devices.

The processor may be arranged to compare the signal strength of the received notification signal against a threshold value and to connect the communications interface to the second antenna when the signal strength exceeds the threshold value.

In this manner the control module/processor may determine the range of the communications device from the vehicle such that the vehicle access process may be controlled based on the proximity of the device to the vehicle. In an alternative arrangement, the communications device may receive communications signals sent from the vehicle and may report back the signal strength of the received signals.

The processor may be arranged to send a challenge signal to the communications device and is arranged to control the vehicle access system in dependence on a response signal received from the communications device at the first antenna.

The processor may be arranged to connect the communications interface to the second antenna in response to a trigger event. The trigger event may be associated with user interaction at an access point on the vehicle. User interaction may comprise pulling a door handle or pushing a button, for example.

The processor may be arranged to compare received signal strength indication (RSSI) values of further communication signals received from the second antenna to a predetermined threshold value and to generate the control signal for the vehicle access system in the event that the received RSSI values exceed the predetermined threshold value. Additionally or alternatively, the processor may be arranged to compare received signal strength indication (RSSI) values of further communication signals received from the second antenna to a received signal strength indication (RSSI) value of the notification signal received at the first antenna.

The vehicle may comprise a plurality of antennas, that is to say, two or more, and, subsequent to detecting the notification signal from the communications device, the processor may be arranged to connect the communications interface to a subset of the plurality of antennas in turn in order to determine an approach direction of the communications device. Additionally or alternatively, the processor may be arranged to connect the communications interface to each of the plurality of antennas in turn in order to determine an approach direction of the communications device.

The processor may be arranged to compare received signal strength indication (RSSI) values at each antenna that is connected to the communications interface in order to determine the approach direction. In an alternative configuration the communications device may return to the control module the received signal strength indication values of communications signals received at the communications device from the selected antenna and such RSSI values of signals received at the communications device may be used to determine an approach direction of the communications device.

The trigger event may be associated with user proximity to the vehicle and the second antenna is selected by the processor to be the closest antenna to the approach direction.

The processor may be arranged to control one or more vehicle functions in dependence on the determined approach direction. The one or more vehicle functions may comprise deployment of door handles. The one or more vehicle functions may comprise operation of a lighting system of the vehicle. The lighting system may comprise an internal or an external lighting system of the vehicle. In embodiments, the one or more vehicle functions may comprise operation of a HVAC system of the vehicle. The one or more vehicle functions may comprise operation of an infotainment system of the vehicle.

The first antenna may be centrally located within the vehicle. The communications signals may be Bluetooth low energy signals.

In an aspect of the present invention there is provided a vehicle access system comprising a control module according to the above aspect of the present invention and a plurality of antennas.

The invention extends to a vehicle comprising a control module or a vehicle access system according to aspects of the present invention.

According to a further aspect of the present invention there is provided a method for controlling operation of a vehicle access system using a control module comprising: a communications interface for sending and receiving communications signals, the interface being configurable to communicate with two or more antennas; a processor for controlling operation of the vehicle access system in dependence on communications signals received at the communications interface from the two or more antennas; and an output for outputting a control signal, the method comprising: configuring the communications interface to connect to a first antenna and scanning signals received from the first antenna for a notification signal from a communications device over a communications channel; configuring the communications interface, in dependence on detecting the notification signal from the communications device at the first antenna, to connect to a second antenna; and generating the control signal for the vehicle access system in dependence on further communications signals from the communications device received at the communications interface from the second antenna.

The invention extends to a computer program product comprising instructions which, when the program is executed by a control module, cause the control module to carry out the method of the further aspect of the present invention. The invention extends to a computer-readable data carrier having stored thereon the computer program product. Optionally, the computer-readable data carrier comprises a non-transitory computer-readable data carrier. A control module for controlling a vehicle access system as described above, wherein the control module comprises an electronic processor having an electrical input for receiving said communications signals; and an electronic memory device electrically coupled to the electronic processor and having instructions stored therein to configure the processor to access the memory device and execute the instructions stored therein such that it is operable to scan for and analyse communications signals received from the antennas via the communication interface.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a known vehicle access system;

Figure 2 shows a known vehicle access system comprising a Bluetooth transmitter;

Figures 3 shows a vehicle access system in accordance with an embodiment of the present invention;

Figure 4 shows a mode of operation of the vehicle access system of Figure 3; and

Figure 5 shows the interaction between a vehicle access system of Figure 3 and a communications device.

DETAILED DESCRIPTION

Figure 1 shows a known passive entry system between a vehicle 10 and a key fob 12. The vehicle 10 comprises a first low frequency (LF) transmitter 14 located in an engine compartment of the vehicle and a second LF transmitter 16 located in a door handle 18 of the vehicle. It is noted that only two transmitters (14, 16) are shown in Figure 1 for clarity and in certain arrangements each door handle may comprise a transmitter. In other arrangements, the transmitter 14 located in the engine compartment may not be present and the passive entry system may, for example, rely on the door handle based transmitters for operation, although other locations within or on the vehicle are envisaged.

The passive entry system further comprises an RF receiver 20 and a control module 22.

The transmitters 14, 16 are arranged to output radio signals at a frequency of 125 kHz. The key fob 12 is configured to receive signals at 125 kHz and transmit signals at a frequency of 433 MHz, The RF receiver 20 is configured to receive signals at a frequency of 433 MHz.

It is noted that the above frequency values are provided by way of example only and may vary between different vehicle markets. The low frequency (LF) range, for example, is generally taken to encompass the range of 30 kHz to 300 kHz. The radio frequency (RF) range is generally taken to encompass the range of 30kHz to 300 GHz. The RF frequency described herein is 433 MHz but the inventors are aware of, for example, other systems that operate at 315 MHz.

In a normal unlock mode of operation, a vehicle occupant in possession of the key fob 12 approaches the vehicle and pulls a door handle 18. A sensor (not shown) in the door handle sends a signal to the control module 22 which arranges for at least one transmitter 14, 16 to send an LF signal which is received by the key fob 12.

In response to receiving the LF signal from the vehicle 10, the key fob is arranged to send an unlock request to the vehicle on the RF signal frequency. The RF signal is received by the receiver 20 which sends the received signal to the control unit 22 which then sends a door unlock signal to a vehicle door associated with the door handle 18.

Figure 2 shows another example of a vehicle access system, in this case, a known system comprising a Bluetooth low energy (Bluetooth LE/BLE) passive entry system. In this example, a vehicle 30 comprises a Bluetooth beacon 32 which is in communication with a smart device 34 (e.g. a smartphone, smartwatch or other suitably Bluetooth enabled device) which is displaying a virtual representation of a key fob 36. The key fob 36 may be part of a computer application on the smart device 34 that has been configured such that the smart device in question is paired with the vehicle.

In vehicle 30, the beacon periodically broadcasts a signal over Bluetooth LE (~2.4 GHz). When the smart device 34 is in range of the Bluetooth beacon associated with the vehicle 30, the computer application on the smart device and a control module 38 associated with the beacon may exchange messages to identify each other and an unlock request may be sent to the vehicle. It is noted that the unlock request may be configured to be sent automatically or via interaction with the virtual key fob 36.

In contrast to the known examples of vehicle access systems presented in Figures 1 and 2, Figure 3 shows a vehicle access system in accordance with an embodiment of the present invention. Figure 3 shows a vehicle 50 in which a control unit, or ECU 60, having a processor module 61, and comprising a Bluetooth low energy (BLE) transceiver 62 is in communication with a plurality of antennas 71, 72, 73, 74, 75, 76. Each of the antennas may be selected and operated by the control unit 60. In the arrangement of Figure 3 the control unit 60 is an electronic control unit within the vehicle. The transceiver 62 equates in the embodiment of Figure 3 to a communications interface which is configurable by the processor 61 of the control unit 60 to be in communication with the antenna 71-76. An output 63 from the ECU 60 may be arranged to send control signals to vehicle systems such as a vehicle door- or door handle locking system.

The vehicle further comprises a telematics control unit (TCU) 78. The TCU 78 comprises an external interface for mobile communications with a mobile telephone network. The TCU 78 is in communication with the ECU 60.

In the arrangement shown in Figure 3, there is one antenna 71 that is located substantially centrally within the vehicle and further antenna 72-76 which are located at, or are each associated with, access points to the vehicle such as side doors and tailgate or trunk lid (boot lid). Typically, such access points, are arranged such that the side doors provide the user access to the cabin or occupant compartment of the vehicle, whilst the tailgate or trunk lid is typically arranged to provide the user access to a luggage- or cargo compartment of the vehicle.

Also shown in Figure 3 is a smart device 80 (such as a smartphone, smartwatch or other suitably Bluetooth enabled device) that is in communication (via signals 82) with the ECU 60 and Bluetooth transceiver 62. The smart device 80 may be equipped with a suitable application (App) 84 to control communication signals exchanged with the vehicle 50.

The vehicle 50 (via the TCU 78) and the smart device 80 are further in communication with an access sharing platform 90. The vehicle 50 may communicate via a mobile telecommunications network and the smart device 80 may communicate either via a mobile telecommunications network or a WiFi network with the access sharing platform 90. The access sharing platform 90 may be located at a remote server or may be a Cloud based service.

The operation of the vehicle access system shown in Figure 3 is now described in relation to Figure 4.

In step 100 the processor 61 of the control unit 60 configures the communications interface (the Bluetooth transceiver 62) to scan for a communications device 80 using the first antenna 71. The control unit 60 (Bluetooth transceiver 62), in response to step 100, starts looking for a notification signal in the form of a general advertising broadcast from a Bluetooth enabled device.

Upon detecting a Bluetooth notification signal from a communications device (in the case of Figure 3 this communications device is the smartphone 80) the ECU 60 may check to see if the communications device 80 is on a list of authorised devices. The ECU 60 may as part of this process extract a device identifier from the notification signal that was received via the first antenna. It is noted that the device 80 may be registered on the access sharing platform 90 and associated with the vehicle 50 as part of a registration process, and the list of authorised devices may be held in a memory associated with the access sharing platform 90 and/or held on an electronic memory device in the vehicle 50 arranged to be accessible to the control unit 60.

Assuming that the communications device 80 is a known/authorised device then the ECU 60 first connects with the device 80 in step 102 and then performs a proximity assessment.

Connection with the device may comprise the ECU 60 sending a challenge signal via the first antenna 71 to the device 80. The challenge signal may be based on a shared secret, i.e. a piece of information known to the ECU 60 and the device 80 such as the vehicle identification number (VIN), a user account identifier, a smart device 80 identifier or another piece of specified user data. The known shared secret may be set during the registration process on the access sharing platform 90 when the smart device 80 is associated with the vehicle 50.

As shown in Figure 5, upon receipt of response signal 82 at the first antenna 71 from the device 80 the ECU 60 is arranged to validate the device 80. If the response from the smart device 80 is validated then the device 80 is trusted and further communications between the device 80 and the vehicle 50 may be processed. In the event that the response from the smart device 80 is not validated then the connection with the device 80 is terminated. Optionally, the device 80 may be put onto a black list either permanently or for a set period of time (e.g. an hour). The black list may be held in a memory associated with the access sharing platform 90 and/or held on an electronic memory device in the vehicle 50 arranged to be accessible to the control unit 60.

Following connection of the vehicle 50 with the smart device 80, the ECU 60 is arranged to perform a proximity check in which the received signal strength indication (RSSI) of communication signals from the smart device 80 are compared to a predetermined threshold value. This threshold represents a certain proximity of the smart device 80 to the vehicle 50. It is noted that Bluetooth LE signals may have a range of 50 metres or more (depending on obstructions) and so this RSSI threshold check ensures that the ECU 60 only continues with the vehicle access process when the smart device 80 is within a predetermined range of the vehicle.

Once the smart device 80 has been determined to be within a predetermined range of the vehicle, the vehicle access process moves from step 102 to step 104 in which the communications interface is configured to connect to each antenna (71, 76) in turn by the ECU 60 and the RSSI of communication signals received at each antenna may be determined.

In step 106, the determined RSSI values at each antenna may be used to determine the approach direction of the smart device, e.g. if antenna 74 records the highest RSSI value then this indicates that the smart device is approaching the door for which antenna 74 is associated. Depending on vehicle packaging constraints, the antenna associated with a door may be located within that door, or alternatively may be located adjacent to the door, for example in part of the vehicle forming the body surrounding the door, as will be understood by one skilled in the art.

In step 108, the ECU 60 outputs a control signal to deploy approach functionality features, e.g. the door handle in the door housing antenna 74 may be deployed from a stowed configuration to a deployed configuration. Door and/or vehicle lights may also be activated.

In step 110, the vehicle user, e.g. the driver or another user, causes an event trigger to be received at the ECU 60. For example, the action of the user pulling a door handle may send an event trigger signal to the ECU 60. Alternatively, a control button mounted on or near the vehicle door handle may be depressed to thereby send an event trigger signal to the ECU 60.

In response to the event trigger in step 110, the ECU module 60 at step 112, is arranged to switch to a second antenna in or associated with the door that has received the user interaction. In the above example, this would comprise the ECU module switching to antenna 74.

In step 114, the signal strength (RSSI) of the communication signals from the smart device 80 are measured at antenna 74.

In step 116, the ECU module performs a comparison of the signal strength at antenna 74 against a second threshold value. If the signal strength at antenna exceeds the threshold value then this indicates that the smart device 80 (and the owner of the device) has reached the vehicle and the vehicle is unlocked (the ECU 60 generates and sends a control signal to the vehicle unlocking system). It is noted that industry standards may require remote unlocking of a vehicle to only occur when the unlocking device (e.g. key fob or in the present embodiment a smart device) is within a given distance of the vehicle.

For example, it may be desirable or necessary for unlocking of a vehicle to only occur when the unlocking device (e.g. key fob or, in the present embodiment, a smart device) is within one metre of the vehicle. Over distances of approximately one metre Bluetooth signals exhibit a roughly linear relationship between signal strength and distance between transmitter and receiver. The signal strength of Bluetooth communication signals sent from the smart device 80 and received at the antenna at the point of entry may therefore be used to confirm the proximity of the smart device 80/user to the vehicle 50 such that the vehicle access system can be controlled to unlock the vehicle.

In the above description it is noted that steps 104, 106, 108 are optional to the operation of the vehicle access system and in an alternative mode of operation the ECU 60 may move directly to step 110 from step 102.

In the above description it is the ECU 60 that controls operation of the various antennas and sends the control signal to the vehicle access system. It is noted however that the Bluetooth transceiver 62 within the ECU 60 may perform some or all of the tasks described above (e.g. a processor within the transceiver 62 may configure a communications interface of the transceiver).

In the above description the signal strength of communications signals received from the smart device 80 at the vehicle antennas is measured. It is noted however that in an alterative arrangement the smart device may determine the signal strength of signals received from the vehicle and report this signal strength back to the vehicle in order for the vehicle access system to be controlled.

The smart device 80 may be any suitable communications device, e.g. a smart phone, smart watch (or other wearable device), or a tablet device.

Many modifications may be made to the above examples without departing from the scope of the present invention as defined in the accompanying claims.

Claims

1. A control module for controlling operation of a vehicle access system, the control module comprising: a communications interface for sending and receiving communications signals, the interface being configurable to communicate with two or more antennas; a processor for controlling operation of the vehicle access system in dependence on communications signals received at the communications interface from the two or more antennas; and an output for outputting a control signal; wherein the processor is arranged to: configure the communications interface to connect to a first antenna and to scan signals received from the first antenna for a notification signal from a communications device over a communications channel; configure the communications interface, in dependence on detecting the notification signal from the communications device at the first antenna, to connect to a second antenna; and generate the control signal for the vehicle access system in dependence on further communications signals from the communications device received at the communications interface from the second antenna.

2. A control module as claimed in Claim 1, wherein the processor is arranged to identify the communications device.

3. A control module as claimed in Claim 2, wherein the processor is arranged to compare a device identifier contained within the notification signal with a list of authorised communications devices.

4. A control module as claimed in any preceding claim, wherein the processor is arranged to compare the signal strength of the received notification signal against a threshold value and to connect the communications interface to the second antenna when the signal strength exceeds the threshold value.

5. A control module as claimed in any preceding claim, wherein the processor is arranged to send a challenge signal to the communications device and is arranged to control the vehicle access system in dependence on a response signal received from the communications device at the first antenna.

6. A control module as claimed in any preceding claim, wherein the processor is arranged to connect the communications interface to the second antenna in response to a trigger event.

7. A control module as claimed in Claim 6, wherein the trigger event is associated with user interaction at an access point on the vehicle.

8. A control module as claimed in Claim 7, wherein the user interaction comprises pulling a door handle.

9. A control module as claimed in Claim 7 or Claim 8, wherein the user interaction comprises pushing a button.

10. A control module as claimed in any one of Claims 6 to 9, wherein the processor is arranged to compare received signal strength indication (RSSI) values of further communication signals received from the second antenna to a predetermined threshold value and to generate the control signal for the vehicle access system in the event that the received RSSI values exceed the predetermined threshold value.

11. A control module as claimed in any one of Claims 6 to 10, wherein the processor is arranged to compare received signal strength indication (RSSI) values of further communication signals received from the second antenna to a received signal strength indication (RSSI) value of the notification signal received at the first antenna.

12. A control module as claimed in any preceding claim, wherein the vehicle comprises a plurality of antennas, and, subsequent to detecting the notification signal from the communications device, the processor is arranged to connect the communications interface to a subset of the plurality of antennas in turn in order to determine an approach direction of the communications device.

13. A control module as claimed in any preceding claim, wherein the vehicle comprises a plurality of antennas, and, subsequent to detecting the notification signal from the communications device, the processor is arranged to connect the communications interface to each of the plurality of antennas in turn in order to determine an approach direction of the communications device.

14. A control module as claimed in Claim 12 or Claim 13, wherein the processor is arranged to compare received signal strength indication (RSSI) values at each antenna that is connected to the communications interface in order to determine the approach direction.

15. A control module as claimed in Claim 14 when dependent on claim 6, wherein the trigger event is associated with user proximity to the vehicle and the second antenna is selected by the processor to be the closest antenna to the approach direction.

16. A control module as claimed in Claim 12 to 14, wherein the processor is arranged to control one or more vehicle functions in dependence on the determined approach direction.

17. A control module as claimed in Claim 16, wherein the one or more vehicle functions comprise deployment of door handles.

18. A control module as claimed in any preceding claim, wherein the first antenna is centrally located within the vehicle.

19. A control module as claimed in any preceding claim, wherein the communications signals are Bluetooth low energy signals.

20. A vehicle access system comprising a control module according to any one of Claims 1 to 19 and a plurality of antennas.

21. A vehicle comprising a control module as claimed in any one of Claims 1 to 19 or a vehicle access system as claimed in Claim 20.

22. A method for controlling operation of a vehicle access system using a control module comprising: a communications interface for sending and receiving communications signals, the interface being configurable to communicate with two or more antennas; a processor for controlling operation of the vehicle access system in dependence on communications signals received at the communications interface from the two or more antennas; and an output for outputting a control signal, the method comprising configuring the communications interface to connect to a first antenna and scanning signals received from the first antenna for a notification signal from a communications device over a communications channel; configuring the communications interface, in dependence on detecting the notification signal from the communications device at the first antenna, to connect to a second antenna; and generating the control signal for the vehicle access system in dependence on further communications signals from the communications device received at the communications interface from the second antenna.

23. A computer program product comprising instructions which, when the program is executed by a control module, cause the control module to carry out the method of Claim 22.

24. A computer-readable data carrier having stored thereon the computer program product of Claim 23.