CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of International Application No. PCT/EP2018/058314, filed Mar. 30, 2018, which claims priority to GB Patent Application 1706191.2, filed Apr. 19, 2017, the contents of both of which are incorporated by reference herein in their entirety.

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 method of operating an access system for a vehicle, to a control unit arranged to control an access system for a vehicle, to an access system for a vehicle and to a vehicle.

BACKGROUND

It is known to provide passive entry and passive starting (PEPS) systems for motor vehicles. 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 over a Radio Frequency (RF) communications channel. 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 universally 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 motor can be provided to unlock the door to provide seamless operation as if the vehicle was already unlocked.

At least in certain embodiments, the present invention attempts to address or mitigate at least some of the shortcomings associated with known vehicle access systems.

SUMMARY OF THE INVENTION

According to an aspect of the present invention there is provided a method of operating an access system for a vehicle, the method comprising: scanning for a first communication signal from a first communications device using a first communication channel; and initiating a vehicle access process in dependence on detecting the first communication signal from the first communications device; wherein the vehicle access process comprises: comparing a received signal strength indication, RSSI, of the received first communication signal to a predetermined threshold signal strength value; sending a challenge signal for a second communications device using a second communication channel in the event that the RSSI of the received first communication signal exceeds the threshold signal strength value; and controlling the vehicle access system in dependence on a response signal received from the second communications device, the response signal having been sent in response to the challenge signal.

In order to at least partially address shortcomings identified with prior art systems, the present invention utilises two communications devices to manage the vehicle access process. For example, in an arrangement where a vehicle owner uses a smart device (such as a smart phone, tablet or smart watch) this may be used as the first communications device above. Such smart devices are provided with Bluetooth® functionality which is an energy efficient communications solution and so the use of such a system as part of the access process will only have limited impact to the battery of the vehicle (since a corresponding Bluetooth® transceiver/receiver on the vehicle would not drain too much energy from the vehicle's battery).

Optionally, the first communications channel may be monitored to determine the likely approach of a vehicle user and, the vehicle may then switch to the second, different, communications channel (e.g. a Low Frequency system) to search for the presence of the second communications device (e.g. a traditional key fob). It is noted that this arrangement has the benefit that vehicle users that do not possess a first communications device may gain vehicle access in the normal manner, e.g. by using the existing vehicle key fob.

Optionally, the first communication signal comprises a signal sent via Bluetooth®. It is noted that the term “Bluetooth” in this context includes all Bluetooth® generations, including the Bluetooth® Low Energy system. It is noted that use of Bluetooth® as the first communications channel allows a “seeking” functionality to be performed by the vehicle for the first communications device with minimal power consumption.

In alternative embodiments, the first communications signal may comprise a signal sent by WiFi.

Optionally, the first communications device is a mobile communications device.

Optionally, the second communications device is configured to allow a user to gain access to a vehicle. For example, the second communications device may be a key fob device.

Optionally, the method comprises identifying a device identifier for the first communications device from the first communication signal and checking if the device identifier corresponds with that of an approved device. Optionally, the method comprises turning on a transmitter for transmitting the challenge signal via the second communication channel in the event that the first communications device is an approved device. The transmitter may comprise, or consist of, a Radio Frequency (RF) transmitter and the second communications channel may comprise, or consist of, an RF channel. Optionally, the transmitter comprises a Low Frequency (LF) transmitter and the second communications channel comprises an LF channel.

Optionally, the method comprises sending a signal strength request signal to the first communications device over the first communication channel and receiving a signal strength confirmation communication signal from the first communications device over the first communications channel, the signal strength confirmation communication signal comprising a signal strength value of the signal strength request signal as received at the first communications device. The method may comprise comparing the signal strength value to a predetermined threshold signal strength value. The method may comprise sending the challenge signal for the second communications device in the event that the signal strength value exceeds the threshold signal strength value.

Optionally, the vehicle is provided with multiple antennas for receiving communication signals sent over the first communication channel, the method comprising comparing the signal strength of signals received from the first communications device at two or more of the antennas to determine at least one of a relative position/location of the first communications device with respect to the vehicle and an approach vector for the first communications device. Optionally, the method comprises turning on a transmitter for transmitting the challenge signal on the side of the vehicle that the first communications device is approaching.

Optionally, the method comprises cancelling the vehicle access process in the event that no response signal is received from the second communications device.

Optionally, the vehicle access process comprises unlocking the vehicle (e.g. unlocking a door, a number of doors, a vehicle boot or stowage compartment).

Optionally, the method comprises determining that the first communications device is moving away from the vehicle in dependence on one or more changes in the signal strength of signals received over the first communications channel from the first communications device. The method may comprise turning on an RF transmitter in order to determine if the second communications device is moving away from the vehicle.

Optionally, the method comprises locking the vehicle in the event that the first and/or second communications devices have left the vicinity of the vehicle. For example, the vehicle may be locked when the second communications device has left the detection area of antenna on the vehicle (in the case of an LF antenna on the vehicle this may correspond to locking the vehicle when the key fob is more than about one metre from the vehicle). Alternatively, the vehicle may determine the distance to the first communications device as it departs the vehicle and may lock the vehicle when the first communications device exceeds a predetermined distance from the vehicle. The distance from the vehicle may be determined from the signal strength of first communications signals received from the first communications device.

Optionally, the vehicle access process comprises locking the vehicle.

Optionally the method comprises sending a locking status message to the first communications device over the first communication channel. Such a locking status message may comprise a confirmation that the vehicle is locked or a message stating that the locking process has failed.

Optionally, the first and second communications devices are located within a single user device.

Optionally, the first communications device is located in a first user device and the second communications device is located in a second user device.

According to an aspect of the present invention there is provided a control unit arranged to control an access system for a vehicle, the control unit comprising: one or more inputs for receiving a first communication signal from a first communications device and a second communication signal from a second communications device; a processor arranged to manage a vehicle access process; and an output arranged to output vehicle access control signals; wherein the processor is arranged to: scan for a first communication signal from a first communications device using a first communication channel; initiate a vehicle access process in dependence on detecting the first communication signal from the first communications device, the vehicle access process comprising comparing a received signal strength indication, RSSI, of the received first communication signal to a predetermined threshold signal strength value and, in the event that the RSSI of the received first communication signal exceeds the threshold signal value, sending from the output a challenge signal for a second communications device using a second communication channel; and wherein the output is arranged to output a vehicle access control signal to control the vehicle access system in dependence on a response signal received from the second communications device, the response signal having been sent in response to the challenge signal.

According to a further aspect of the present invention there is provided an access system for a vehicle comprising a control unit according to an above aspect of the present invention, a first antenna arranged to operate over the first communication channel and a second antenna arranged to operate over the second communication channel.

According to a further aspect of the present invention there is provided a vehicle comprising a control unit or an access system according to an above aspect of the present invention.

According to a further aspect of the present invention there is provided a computer program product comprising instructions which, when a program of the program product is executed by a computer, cause the computer to carry out the method of the above aspect of the present invention. The computer program product may be downloadable from a communication network and/or stored on a computer-readable and/or microprocessor-executable medium.

According to a further aspect of the present invention there is provided a non-transitory computer-readable medium having stored thereon the computer program product of a foregoing aspect of the invention.

In an embodiment of the abovementioned control unit, the processor 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, wherein the processor is configured to access the memory device and execute the instructions stored therein such that it is operable to detect that the vehicle is being approached by a suitable (e.g. Bluetooth®-enabled) device based on a value of the communications signals received at the electrical input; and determine that the device is known and command the vehicle entry system to perform one or more actions.

According to a further aspect of the present invention there is provided a method of operating an access system for a vehicle, the method comprising: scanning for a first communication signal from a first communications device using a first communication channel; and initiating a vehicle access process in dependence on detecting the first communication signal from the first communications device; wherein the vehicle access process comprises establishing a second communication channel in dependence on the first communication channel; and controlling the vehicle access system in dependence on communication signals received from a second communications device over the second communication channel.

In an embodiment, a handshaking process between the first communications device and the vehicle may take place over the first communications channel in order to establish the parameters for communication over the first communications channel. In response to the first communications channel being set up the second communications channel between the vehicle and the second communications device may then be set up and communications within this second communications channel may be used to manage the vehicle access process.

According to a further aspect of the present invention there is provided a method of operating an access system for a vehicle, the method comprising: scanning for a first communication signal from a first communications device using a first communication channel; and initiating a vehicle access process in dependence on detecting the first communication signal from the first communications device; wherein the vehicle access process comprises sending a challenge signal for a second communications device using a second communication channel; and controlling the vehicle access system in dependence on a response signal received from the second communications device, the response signal having been sent in response to the challenge signal.

Optionally, the method comprises comparing a received signal strength indication (RSSI) of the received first communication signal to a predetermined threshold signal strength value. In this manner the distance between the first communications device and the vehicle may effectively be determined by measuring the signal strength of the communications signal that is received when scanning for the first communications device. The method may comprise sending the challenge signal for the second communications device in the event that the RSSI of the received first communication signal exceeds the threshold signal strength value.

According to an aspect of the present invention there is provided a control unit arranged to control an access system for a vehicle, the control unit comprising: one or more inputs for receiving a first communication signal from a first communications device and a second communication signal from a second communications device; a processor arranged to manage a vehicle access process; and an output arranged to output vehicle access control signals; wherein the processor is arranged to: scan for a first communication signal from a first communications device using a first communication channel; initiate a vehicle access process in dependence on detecting the first communication signal from the first communications device, the vehicle access process comprising sending from the output a challenge signal for a second communications device using a second communication channel; and wherein the output is arranged to output a vehicle access control signal to control the vehicle access system in dependence on a response signal received from the second communications device, the response signal having been sent in response to the challenge signal.

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.

