Wireless auxiliary device communication

Abstract

A first aspect of the invention relates to an auxiliary device 200 for a vehicle 700, the auxiliary device comprising a receiver (210, figure 2) and one or more processors (220) collectively configure

Description

TECHNICAL FIELD The present disclosure relates to a wireless auxiliary device communication protocol. Aspects of the invention relate to an auxiliary device for a vehicle, to a communication module, to a system, to a vehicle, to a method and to computer readable instructions. BACKGROUND It is known to provide wired communication networks for transmitting and receiving data related to vehicle operation and user entertainment functions. For example, many vehicles use a bus network comprising wired connections between controllers and actuators and sensors of the vehicle. As the complexity of vehicle systems increases with addition of new vehicle functions, the electrical architecture of the vehicle comprises an increasing number of cables, connectors and other electrical components to support the communication network. Similarly, when adding new accessories or devices to a vehicle, integrating them into the existing electrical architecture can be complicated. This increases the weight of the vehicle, reducing range and efficiency and increasing manufacturing costs and complexity. It is an aim of the present invention to address one or more of the disadvantages associated with the prior art. SUMMARY OF THE INVENTION Aspects and embodiments of the invention provide an auxiliary device fora vehicle, a communication module, a system, a vehicle, a method and computer readable instructions as claimed in the appended claims. The invention relates to a communication module and an auxiliary device in communication with one another via a wireless communication protocol. Using time-of-flight measurements, the auxiliary device is able to determine whether a command from one or more communication modules is intended for that auxiliary device or whether the command should be ignored. According to an aspect of the present invention there is provided an auxiliary device for a vehicle, the auxiliary device comprising a receiver and one or more processors collectively configured to: receive at least one signal, via a wireless communication protocol, from each of a plurality of transmitters, wherein at least one of the received signal comprises one or more instructions comprising a command and a command location; calculate a distance of the auxiliary device from each of the plurality of transmitters based on a time of flight measurement for the signal received from each of the plurality of transmitters wherein said signal comprises an indication of a transmission time; determine a location of the auxiliary device relative to the vehicle based on the calculated distance from each of the plurality of transmitters; and in accordance with a determination that the location complies with the command location, perform the command. By implementing a wireless communication protocol within the vehicle which is configured to facilitate communication and data transfer between embedded vehicle systems for performing vehicle functions, an amount of wiring in a vehicle for communication purposes can be reduced. This simplifies manufacture of the vehicle and reduces cost. The wireless communication protocol may increase resilience of the vehicle, and for example can provide redundancy when used in addition to wired communication networks. The weight of the vehicle may also be reduced in this way, which may improve a fuel efficiency or range of the vehicle. Furthermore, the use of time of flight measurements between an auxiliary device and a plurality of transmitters allows an auxiliary device to receive all transmissions from the transmitters but only act on the transmissions that are intended for that auxiliary device. This ensures that the commands issued by the transmitters are only ever carried out by the intended auxiliary device, and not an alternative auxiliary device within the vehicle or an auxiliary device in another vehicle. The auxiliary device can be considered as an accessory device to the vehicle. For example, the auxiliary device can comprise accessory devices such as a roof box, lighting, display screen etc. In an embodiment, the one or more processors may further collectively be configured to: in accordance with a determination that the location does not match the command location, forgo performing the command. This ensures that the auxiliary device only performs commands that are intended forthat auxiliary device and the auxiliary device effectively ignores all other commands. In an embodiment, the command location is a location relative to the vehicle. In an embodiment, the location may comply with the command location when the location is within the proximity of the command location. For example, the location complies with the command location when the location is within a range of values comprising the command location. This provides fora certain degree of measurement uncertainty thus enabling an auxiliary device to act on a command even if the location does not precisely comply with the command location. In an embodiment, the wireless communication protocol may be ultrawideband (UWB) and / or Bluetooth. The use of UWB allows band signals to coexist without blocking each other. Bluetooth (e.g., BLE) is beneficial as it has no limitation on the number of devices except where the supplier has placed a limitation on what it can handle and has maximum bandwidth capability. Further, the implementation of a wireless communication protocol into a vehicle may be simplified by using standardised technology. In an embodiment, the auxiliary device may further be configured to: determine a geographical location of the vehicle; determine if the command is permitted for the geographical location; and in accordance with a determination that the command is not permitted for the geographical location, forgo performing the command. This has the advantage of preventing auxiliary devices from activating in regions where that auxiliary device is not permitted. For example, the use of dash cams is not permitted in certain countries. When the auxiliary device crosses a border into a country where dash cams are not allowed, the dash cam would be prevented from activating and / or would turn off. In an embodiment, the auxiliary device may be configured to receive the at least one signal from each of four or more transmitters. The use of at least four transmitters allows an exact determination of the location of the auxiliary device. In an embodiment, the auxiliary device may be configured to receive the at least one signal from three or more transmitters. The use of at least three transmitters allows the location of the auxiliary device to be determined with a degree of accuracy. According to another aspect of the present invention, there is provided a communication module for controlling an auxiliary device for a vehicle, the communication module configured to be connected to an Electronic Control Unit and comprising a transmitter and one or more processors collectively configured to: receive data signals from the vehicle; convert the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location; and transmit the one or more instructions and a transmission time to the auxiliary device using a wireless communication protocol. By implementing a wireless communication protocol within the vehicle which is configured to facilitate communication and data transfer between embedded vehicle systems for performing vehicle functions, an amount of wiring in a vehicle for communication purposes can be reduced. This simplifies manufacture of the vehicle, and reduces cost. The wireless communication protocol may increase resilience of the vehicle, and for example can provide redundancy when used in addition to wired communication networks. The weight of the vehicle may also be reduced in this way, which may improve a fuel efficiency or range of the vehicle. Furthermore, transmitting a transmission time between an auxiliary device and the communication module ensures that the commands issued by the communication module are only ever carried out by the intended auxiliary device, and not an alternative auxiliary device within the vehicle or an auxiliary device in another vehicle. In an embodiment, the command location may specify a position within a 2D or 3D space relative to the vehicle. In an embodiment, the communication module may be configured to be placed at a position in the vehicle which does not move relative to the vehicle structure. For example, the communication module is configured to be placed at a stationary position relative to other components of the vehicle. As an example, the communication module may be placed at the dashboard but not at the car door as the car door is moveable. This ensure that the location determination for the auxiliary devices is accurate as it is dependent on time of flight measurements which rely on distances between the control module and the auxiliary devices. Such distances would be variable if the control module were placed on a movable component of the vehicle. In an embodiment, the auxiliary device may comprise a receiver only, not a transmitter and / or the communication module may comprise a transmitter only, not a receiver. This improves the security of the system and prevents signals received from outside the vehicle from issuing commands and controlling the vehicle. According to another aspect of the present invention, there is provided a system comprising a plurality of communication modules for controlling an auxiliary device for a vehicle. The system comprises one or more controllers collectively comprising at least one electronic processor having an electrical input for receiving an input signal; and at least one memory device electrically coupled to the at least one electronic processor and having instructions stored therein; and wherein the at least one electronic processor is configured to access the at least one memory device and execute the instructions thereon so as to control an auxiliary device for a vehicle. In an embodiment, the system may further comprise one or more auxiliary devices according to any preceding statement. In an embodiment, the one or more instructions and the transmission time may be received within the same signal, or wherein the one or more instructions and the transmission time are received within different signals. The use of different signals allows different wireless communication protocols to be used for the one or more instructions and the transmission time. In an embodiment, the transmission time may be received via ultrawideband and the one or more instructions are transmitted via Bluetooth. This is beneficial in existing systems which employ Bluetooth as it enables minimal changes to the system whilst still providing a time of flight measurement via the use of ultrawideband. According to another aspect of the present invention, there is provided a vehicle comprising the system of any preceding statement. According to another aspect of the present invention, there is provided a method of controlling an auxiliary device associated with a vehicle, the method comprising: receiving at the auxiliary device, via a wireless communication protocol, one or more instructions from a plurality of transmitters, wherein the one or more instructions comprise a command and a command location; calculating a distance of the auxiliary device from each of the plurality of transmitters based on a time of flight measurement for a signal received from each of the plurality of transmitters, wherein said signal comprises a transmission time; determining a location of the auxiliary device relative to the vehicle based on the calculated distances from each of the plurality of transmitters; in accordance with a determination that the location matches the command location, performing the command. In an embodiment, the method may further comprise in accordance with a determination that the location does not match the command location, forgo performing the command. By implementing a wireless communication protocol within the vehicle which is configured to facilitate communication and data transfer between embedded vehicle systems for performing vehicle functions, an amount of wiring in a vehicle for communication purposes can be reduced. This simplifies manufacture of the vehicle, and reduces cost. The wireless communication protocol may increase resilience of the vehicle, and for example can provide redundancy when used in addition to wired communication networks. The weight of the vehicle may also be reduced in this way, which may improve a fuel efficiency or range of the vehicle. Furthermore, the use of time of flight measurements between an auxiliary device and a plurality of transmitters allows an auxiliary device to receive all transmissions from the transmitters but only act on the transmissions that are intended for that auxiliary device. This ensures that the commands issued by the transmitters are only ever carried out by the intended auxiliary device, and not by an alternative auxiliary device within or in the vicinity of the vehicle or an auxiliary device in another vehicle. In an embodiment, the method may further comprise: determining a geographical location of the vehicle; determining if the command is permitted for the geographical location; and in accordance with a determination that the command is not permitted for the geographical location, forgo performing the command. This has the advantage of preventing auxiliary devices from activating in regions where that auxiliary device is not permitted. For example, the use of dash cams is not permitted in certain countries. When the auxiliary device crosses a border into a country where dash cams are not allowed, the dash cam would be prevented from activating and / or would turn off. In an embodiment, the method may further comprise: receiving data signals from the vehicle; converting the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location; and transmitting the one or more instructions and a transmission time to an auxiliary device using a wireless communication protocol. In an embodiment, the method may further comprise receiving the one or more instructions and a respective transmission time from each of four or more transmitters. The use of at least four transmitters allows an exact determination of the location of the auxiliary device. In an embodiment, the method may further comprise receiving the one or more instructions and a respective transmission time from each of three or more transmitters. The use of at least three transmitters allows the location of the auxiliary device to be determined with a degree of accuracy. According to another aspect of the present invention, there is provided a method of controlling a communication module, the method comprising: receiving data signals from the vehicle; converting the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location; and transmitting the one or more instructions and a transmission time to an auxiliary device using a wireless communication protocol. In an embodiment, the one or more instructions and the transmission time may be received within the same signal, or wherein the one or more instructions and the transmission time may be received within different signals. According to another aspect of the present invention, there is provided, computer readable instructions which, when executed by a computer, are arranged to perform the method according to any preceding statement. 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 anyway 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 block diagram illustrating a communication system according to an embodiment of the invention; Figure 2 shows a block diagram illustrating an auxiliary device according to an embodiment of the invention; Figure 3 shows a block diagram illustrating a wireless communication system according to an embodiment of the invention; Figure 4 shows an illustration of how the wireless communication system may be installed in a vehicle according to an embodiment of the invention; Figure 5 shows a flowchart illustrating a method for controlling a communication module according to an embodiment of the invention; Figure 6 shows a flowchart illustrating a method for controlling an auxiliary device; and Figure 7 shows a vehicle in accordance with an embodiment of the invention. DETAILED DESCRIPTION The present disclosure relates to an auxiliary device and a communication module for controlling such an auxiliary device and corresponding methods. The auxiliary device and communication module work in communication under a wireless communication protocol within a system to enable auxiliary devices to be controlled wirelessly. The wireless communication protocol may be used to enable communications (i.e., the transmission and reception of data) between systems of the vehicle, such as controllers of the vehicle and sensors, actuators, input units or output units of the vehicle. As a result, an amount of electrical wiring required when manufacturing the vehicle is reduced. Thereby, the weight of the vehicle can be reduced and improvements in vehicle efficiency and range can be increased. Furthermore, the disclosure allows for new auxiliary devices to be easily added retrospectively. The wireless communication system is particularly advantageous when a central controller, such as a central compute unit, controls the vehicle’s functions. The wireless communication protocol may be provided for enabling wireless communications between vehicle systems such as controllers, sensors and actuators, and may be understood as an intra-vehicle network. Further, the use of time-of-flight measurements provides for increased cyber-security by allowing the location of the auxiliary device to be determined and ensuring the auxiliary device only executes commands when the auxiliary device is at a specific location. By employing time-of-flight measurements, the location of the auxiliary device determines whether a command is to be executed based on its location hence provides more secure communication than the prior art systems. Additionally, any auxiliary device can be transferred from one vehicle to another without the need to ‘pair’ or ‘calibrate’ it to the new vehicle. This is due to the time-of-flight measurements which enable the auxiliary devices to function based on a location command. For example, a roof box placed on top of a first vehicle would still function when placed on top of a second vehicle as its relative position on the second vehicle is the same as its relative position on the first vehicle, without having to pair with the second vehicle. If a wireless communication protocol such as UWB is employed, this location based process has the advantage of avoiding complicated pairing procedures between communication modules and auxiliary devices. A communication module 110 of a vehicle 700 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1 and an auxiliary device 200 in accordance with an embodiment of the present invention is described with reference to accompanying Figure 2. As shown in Figure 7, at least one auxiliary device 200 and / or at least one communication module 110 can be installed in a vehicle 700, such as an automotive vehicle. The communication module 110 can be installed as part of communication system 100 and connected to an Electronic Control Unit (ECU) 140. With reference to Figure 1, there is illustrated a communication system 100 comprising a communication module 110 for controlling an auxiliary device 200, such as the auxiliary device 200 shown in Figure 2, which is described in detail below. The communication system 100 as illustrated in Figure 1 comprises a communication module 110 and an ECU 140 wherein the communication module 110 is electrically coupled to the ECU 140. The communication 7 module 110 may be electrically coupled to the ECU 140 using a wired connection. The communication module 110 is configured to receive vehicle data from the ECU 140 and transmit a control signal based on the vehicle data. The communication module 110 comprises at least one transmitter 130 and processing means 120. The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The processing means 120 may be electrically coupled to a memory means configured to store instructions. The communication system 100, and in particular the communication module 110, is configured to establish a wireless communication network via a wireless communication protocol with one or more wireless receivers of a vehicle, each of the one or more wireless receivers being associated with a respective auxiliary device (providing a function of the vehicle). Establishing the wireless communication network may comprise steps including one or more of broadcasting a network identifier of the wireless communication network, identifying the one or more wireless receivers, optionally performing a handshake or authentication process with identified wireless receivers, and transmitting connection information with the one or more wireless receivers indicative of a band or channel to be used for wireless communication. That is, the communication system 100 may be configured to be operable as an access point for the wireless communication network, and the one or more wireless receivers of the vehicle may be connectable as client nodes of the wireless communication network. In some examples, the communication system 100 may also communicate with an external network, such as a cellular network. In this disclosure, where reference is made to a “wireless communication protocol”, it should be understood that any suitable type of wireless communication network may be used. The wireless communication protocol can be a radio communication protocol. In one example, the wireless communication protocol is Ultrawideband (UWB) and / or Bluetooth®. The communication system 100 transmits one or more signals via the wireless communication protocol to one or more auxiliary devices of the vehicle, where each of the one or more auxiliary devices is associated with a function of the vehicle. For example, one auxiliary device may be a speaker and associated with the function of providing an audible output. The functions of the vehicle may comprise a vehicle operation function, such as a function related to travel or movement of the vehicle, or may comprise an entertainment function related to user entertainment. The vehicle operation functions may comprise one or more of an advanced driverassistance system (ADAS), motion control, acceleration, braking, radar, safety or steering function. The entertainment function may be a function of a rear-seat entertainment module, or of one or more audio or video output devices of the vehicle. The functions of the vehicle may further comprise other functions, such as vehicle functions relating to climate control, seat or steering wheel heating, or seat or window position. The communication module 110 can be arranged to receive a signal from the ECU 140 of the vehicle. The signal is an electrical signal which can be indicative of a trigger event associated with a function of the vehicle. The ECU signal (which remains secret throughout the process) triggers the communication module 110 to broadcast an instruction signal (e.g., ECU signal = Car is "unlocked", instruction signal = "roof-box lock open"). There may be several ECU signals that induce the same instruction signal (e.g., ECU signal = phone application says "open roof-box but don't unlock car"). As the signal is sent through the communication module 110, even if a third party intercepts and interprets the instruction signal, they cannot know which ECU signal induced it and therefore cannot reverse engineer it. The present invention therefore allows for instructions signals, generated by the ECU, to be transmitted without identifying the ECU or the original ECU signal. For example, the trigger signal may comprise data indicative of a trigger event associated with a first function of the vehicle. The trigger event may correspond to a user input requesting the vehicle function, or may be an automated trigger event determined based on a certain condition being met. For example, many vehicle functions may be associated with trigger events which occur when a vehicle condition is met. The vehicle condition may relate to a vehicle property such as vehicle speed or acceleration, or may relate to data received from external devices or sensors of the vehicle, such as the detection of an object or receipt of a command signal from an external device. In another example, the trigger event may comprise receipt of a predetermined or periodic control signal associated with the first function of the vehicle, or receipt of sensor data associated with the first function of the vehicle. In an example, the trigger can be dependent on a "drive mode" (e.g., modes such as comfort, sport, eco, etc.), a security status (e.g., locked, unlocked, alarmed, etc.), a power mode (e.g., which powered systems are on or off at any moment) etc. It should be understood that there may be many suitable trigger events associated with various vehicle functions, and that the present disclosure should not be limited to the examples above. The communication module 110 is arranged to transmit a signal comprising data associated with a first function of the vehicle to one or more auxiliary devices 200 of the vehicle. The data may be data for controlling the first function of the vehicle. For example, if the first function relates to operation of an electric window of the vehicle, the data may be indicative of a direction in which the window is to be driven or a position at which the window is to be positioned. It should be understood that this is merely an example, and that many other vehicle functions may be controlled in a similar way. The communication module 110 is configured for one way wireless communication from the communication module 110 to any listening receivers. In this way, the CAN bus is prevented from being accessed such that unpermitted sources cannot attempt to access the CAN bus via the communication module 110. The signal transmitted by the communication module 110 can be listened to by any other device. As such, the signal does not contain important vehicle information. The signal received by the communication module 110 is indicative of a function that an auxiliary device is to carry out. On receipt of the signal at the communication module 110, the communication module 110 converts the signal into one or more instructions. The one or more instructions are indicative of a function to be carried out and provide information as to what auxiliary device is to carry out the function. The one or more instructions comprise a command and a command location. The command provides an instruction for the auxiliary device to enter a particular state or complete a particular function. For example, the command may be directed to lights to turn off, turn on, change colour etc (e.g., footwell lights, glass frame lights), to a tread plate to display a particular visual, to a roof box to lock or unlock, to a dash camera to turn on or off, to one or more components of an audio system to turn on or off, to a hearing loop etc. The command location is indicative of the location of auxiliary device which is to carry out the particular function. The command location may be a coordinate position relative to the vehicle. For example, the command location may be (x1, y1, z1). Whilst the signal can be heard by any suitable device within the vicinity of the communication module 110, the command location is used so that only relevant / intended devices act on the command. For example, an auxiliary device from another vehicle may receive the signal from the communication module 110 but does not act on the command as the command location does not align with the location of that auxiliary device. Taken together, the command and the command location set out an instruction to be performed by an auxiliary device if that auxiliary device is at the command location. As an example, the one or more instructions (comprising the command and command location) may be to turn on footwell lights if location is (x1, y1, z1). The one or more instructions are transmitted to one or more auxiliary devices using a wireless communication protocol. A transmission time is also transmitted to the one or more auxiliary devices. The one or more instructions and the transmission time can be sent at the same time using the same wireless communication protocol. However, they may be sent using different wireless communication protocols. For example, the one or more instructions may be sent using Bluetooth® (BLE) and the transmission time may be sent using ultrawideband. The transmission time alerts the auxiliary device to the time that the signal was transmitted from the communication module 110 and is used by the auxiliary device to perform a time of flight measurement as described with reference to Figures 2 and 3. With reference to Figure 2, there is illustrated an auxiliary device 200 for installation within, around, and / or on a vehicle 700. The auxiliary device may be an accessory device for installation within, around and / or on a vehicle 700 such as a roof box, lighting, display screens, heated elements etc. The auxiliary device 200 as illustrated in Figure 2 comprises a receiver 210 and processing means 220. The auxiliary device may also comprise memory means. The processing means 220 may be one or more electronic processing device which operably executes computer-readable instructions. The memory means may be one or more memory device. The memory means can be electrically coupled to the processing means 220. The auxiliary device 200 can be any device which provides a function to the vehicle 700. For example, the auxiliary device 200 can be any of the following: dynamic tread plate, light strips, aperture highlighting, LED arrays, illuminated bonnet lettering control, audio device, LCD displays, HUD, air freshener, towing electronics, towing mirror, camera, roof box, heated component (e.g., heated armrest), fan, hearing loop, etc. Typically, such auxiliary devices (accessory devices) have selectable modes such as on / off, open / closed / locked / unlocked, RGB, music etc. It will be appreciated that this list is not exhaustive and other auxiliary devices and different modes are possible. The auxiliary device 200 is configured to receive, via receiver 210, at least one signal from a transmitter via a wireless communication protocol. The wireless communication protocol is Ultra Wide Band (UWB) and / or Bluetooth®. As discussed in relation to the communication module 110 of Figure 1, the at least one signal comprises one or more instructions comprising a command and a command location. The auxiliary device 200 also receives a transmission time from the transmitter. On receipt of the transmission time, the auxiliary device 200 calculates a distance of the auxiliary device 200 from the transmitter that provided the signal. The distance is calculated by performing a time of flight calculation. The auxiliary device 200 uses the transmission time and the receipt time (time the signal was received by the transmitter) to perform a speed, distance, time calculation. Such time of flight techniques are known in the art and any suitable technique may be used. Based on the transmission time and the receipt time, the auxiliary device 200 determines the time it took the signal to travel from the transmitter to the receiver 210. Using the determined time of flight and the knowledge that the signal travelled at the speed of light (c), the auxiliary device 200 calculates the distance it is from the transmitter using: D = cT Where D is the distance between the auxiliary device 200 and the transmitter, c is the speed of light, and T is the time of flight of the signal. Based on the calculated distance, the auxiliary device 200 determines a location of the auxiliary device 200 relative to the vehicle. To enable the auxiliary device 200 to determine a more accurate location, the auxiliary device 200 receives at least one signal and a transmission time from a plurality of transmitters. One or two transmitters may be used to limit the possible locations. In the case of a single transmitter, the possible locations are limited to the surface of a sphere. In the case of two transmitters, the possible locations are limited to the circumference of a circle. To narrow down the possible locations further, incorrect locations can be eliminated. For example, the vehicle has well-known dimensions and a well-known structure that can be used to identify and eliminate incorrect locations. For example, the surface of the sphere or the circumference of the circle may include locations located outside the vehicle such as 1m under the road. Such a location for the auxiliary device is incorrect such that these locations can be disregarded. The use of three transmitters allows the auxiliary device 200 to perform a triangulation calculation to determine two possible locations. The use of four transmitters allows the auxiliary device 200 to determine a single location rather than multiple possible locations. If the determined location of the auxiliary device 200 complies with the command location, the auxiliary device 200 performs the command. For example, the signal received by the auxiliary device 200 from a plurality of transmitters (communication modules 110) is to unlock if at position (x2, y2, z2). If the auxiliary device 200 determines it is at position (x2, y2, z2), it unlocks. If the auxiliary device 200 determines it is at position (x3, y3, z3) it ignores the command. Figure 3 illustrates a wireless communication system 300 of a vehicle. The wireless communication system comprises a plurality of communication modules 110a, 110b, 110c, 110d and a plurality of auxiliary devices 200a, 200b, 200c. It will be appreciated that four communication modules 110a, 110b, 110c, 110d are shown for illustration purposes only and that a different number of communication modules may be implemented. Similarly, three auxiliary devices 200a, 200b, 200c are shown for illustration purposes only and the skilled person appreciates that any number of auxiliary devices may be implemented. The communication modules 110a, 110b, 110c, 110d are the same as the communication module 110 discussed in relation to Figure 1 and the auxiliary devices 200a, 200b, 200c are the same as the auxiliary device 200 discussed in relation to Figure 2. In the example of Figure 3, wired communication connections are shown with solid arrows, and wireless communication connections are shown with dashed arrows. Each communication module 110a, 110b, 110c, 110d is wired to the ECU 140. Whilst each of the communication modules 110a, 110b, 110c, 110d are shown in Figure 3 as connected to the same ECU 140, one or more of the communication modules could be connected to a different ECU. Each of the auxiliary devices 200a, 200b, 200c are configured to wirelessly receive one or more signals from each of the communication modules 110a, 110b, 110c, 110d. Figure 4 illustrates an example of how the wireless communication system 300 of Figure 3 may be implemented in an automotive vehicle 700. As shown, the auxiliary devices 200a, 200b, 200c and the communication modules 110a, 110b, 110c, 110d may be distributed around the vehicle 700. It would be understood that a typical automotive vehicle may comprise a significant number of sensors, actuators, input units and output unit arranged around the vehicle 700, with locations that cannot always be easily adapted. Thus, by establishing the wireless communication network, the vehicle 700 can be controlled with a plurality of communication modules 110a, 110b, 110c, 110d, and the vehicle 700 can be manufactured with a significant reduction in wiring in the vehicle’s electrical architecture. This can achieve significant reductions in vehicle weight and consequently improvements in the vehicle’s efficiency and range. Furthermore, the wireless communication system 300 provides for ease of installation due to the fewer wires and connections being required. This also allows auxiliary devices to be retrofitted to cars easily after manufacture as wired connections and restructuring is minimised or not required. Figure 5 illustrates a method 500 for controlling a communication module according to an embodiment of the invention. The method 500 may be performed by the communication module 110 of Figure 1 or any of the communication modules 110a, 110b, 110c, 110d of Figures 3 and 4. In particular, memory means of the communication module may comprise computer-readable instructions which, when executed by the processing means 120, perform the method 500 according to an embodiment of the invention. The method 500 comprises, at step 510, receiving at the communication module, data signals from a vehicle. The communication module receives the data signals via a wired connection to an ECU of the vehicle. The use of a wired connection allows the communication module to be configured without a receiver and thus prevents the communication module from receiving wireless signals from unpermitted sources. The data signals provide an indication to the communication module of a function to be performed by a particular auxiliary device. The data signals may be sent to the communication module in response to a trigger event. The trigger event may correspond to a user input requesting the vehicle function, or may be an automated trigger event determined based on a certain condition being met. The trigger event may comprise one or more of: receipt of a user input associated with the function of the vehicle; receipt of sensor data associated with the function of the vehicle; receipt of a predetermined or periodic control signal associated with the function of the vehicle; ora determination of a vehicle condition meeting or exceeding a predetermined threshold condition. The trigger can be dependent on a "drive mode" (e.g., modes such as comfort, sport, eco, etc.), a security status (e.g., locked, unlocked, alarmed, etc.), a power mode (e.g., which powered systems are on or off at any moment) etc. It should be understood that other trigger events are possible, and that the trigger events provided above are for example only. The communication module converts, at step 520, the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location. The one or more instructions are indicative of a function to be carried out and provide information as to what auxiliary device is to carry out the function. The command provides an instruction for the auxiliary device to enter a particular state or complete / carry out a particular function. For example, the command may be directed to lights to turn off, turn on, change colour etc (e.g., footwell lights, glass frame lights), to a tread plate to display a particular visual, to a roof box to lock or unlock, to a dash camera to turn on or off, to one or more components of an audio system to turn on or off, to a hearing loop etc. The command location is indicative of the location of the auxiliary device which is to carry out the particular function. The command location may be a coordinate position relative to the vehicle. For example, the command location may be (x1, y1, z1). Taken together, the command and the command location set out an instruction to be performed by an auxiliary device if that auxiliary device is at the command location. As an example, the one or more instructions (comprising the command and command location) may be to turn on footwell lights if location is (x1, y1, z1). In this way, an auxiliary device with command location (x1, y1, z1) will perform the command whereas an auxiliary device with command location (x6, y7, z8) will not perform the command. The one or more instructions and a transmission time are transmitted, at step 530, to one or more auxiliary devices using a wireless communication protocol. The transmission time may be transmitted with the one or more instructions or it may be transmitted separately. For example, the transmission time may be transmitted with a first signal using a first wireless communication protocol and the one or more instructions may be transmitted with a second signal using a second wireless communication protocol. The first and second wireless communication protocol may be the same or they may be different (e.g., the first wireless communication protocol is UWB and the second wireless communication protocol is Bluetooth®). The transmission time corresponds to the time at which the communication module sent the signal to the auxiliary device. The communication module can therefore have an internal clock which is synchronised with internal clock of the auxiliary device to enable the auxiliary device to perform a time of flight calculation. Figure 6 illustrates a method 600 for controlling an auxiliary device associated with a vehicle according to an embodiment of the invention. The method 600 may be performed by the auxiliary device 200 of Figure 2 or any of the auxiliary devices 200a, 200b, 200c of Figures 3 and 4. In particular, memory means of the auxiliary device 200 may comprise computer-readable instructions which, when executed by the processing means 220, perform the method 600 according to an embodiment of the invention. Method 600 can be performed in combination with method 500. The method 600 comprises, at step 610, receiving one or more instructions at the auxiliary device from a plurality of transmitters via a wireless communication protocol. The one or more instructions comprise a command and a command location. The plurality of transmitters correspond to a plurality of communication modules, such as the communication module discussed in relation to Figure 1. As discussed in relation to method 500, the one or more instructions are indicative of a function to be carried out and provide information as to what auxiliary device is to carry out the function. The command provides an instruction for the auxiliary device to enter a particular state or complete / carry out a particular function. For example, the command may be directed to lights to turn off, turn on, change colour etc (e.g., footwell lights, glass frame lights), to a tread plate to display a particular visual, to a roof box to lock or unlock, to a dash camera to turn on or off, to one or more components of an audio system to turn on or off, to a hearing loop etc. The command location is indicative of the auxiliary device which is to carry out the particular function. The command location may be a coordinate position relative to the vehicle. For example, the command location may be (x1, y1, z1). Taken together, the command and the command location set out an instruction to be performed by an auxiliary device if that auxiliary device is at the command location. As an example, the one or more instructions (comprising the command and command location) may be to turn on footwell lights if location is (x1, y1, z1). The method 600 further comprises, at step 620, calculating a distance of the auxiliary device from each of the plurality of transmitters based on a time of flight measurement for a signal received from each of the plurality of transmitters, wherein said signal comprises a transmission time. The distance is calculated by performing a time of flight calculation. The auxiliary device uses the transmission time and the receipt time (time the signal was received by the transmitter) to perform a speed, distance, time calculation. Based on the transmission time and the receipt time, the auxiliary device determines the time it took the signal to travel from the transmitter to the receiver. Using the determined time of flight and the knowledge that the signal travelled at the speed of light (c), the auxiliary device calculates the distance it is from each transmitter using: D=cT Where D is the distance between the auxiliary device and the respective transmitter, c is the speed of light, and T is the time of flight of the signal. The auxiliary device performs the calculation for each transmitter it receives a signal from. The method 600 proceeds, at step 630, with the auxiliary device determining a location of the auxiliary device relative to the vehicle based on the calculated distances from each of the plurality of transmitters. Any number of transmitters can be implemented. The use of three transmitters enables the auxiliary device to determine two possible locations from the distance calculations. If higher accuracy is required, four transmitters can be implemented to determine a single location. In the case of one or two transmitters, the structure and dimensions of the vehicle can be used to disregard improbable locations such as underthe body of the vehicle (i.e., underthe road surface). This allows fewer transmitters to be used that provide a manageable number of possible locations. Considering the case of four transmitters, the distance calculation from the first transmitter allows the auxiliary device to limit its location to the surface of a sphere, the distance calculation from the second transmitter in combination with the first transmitter allows the auxiliary device to limit its location to a circle, the distance calculation from the third transmitter in combination with the first transmitter and the second transmitter allows the auxiliary device to limit its location to two points on that circle, and the distance calculation from the fourth transmitter in combination with the first transmitter, the second transmitter, and the third transmitter allows the auxiliary device to limit its location to one of those two points. As such, the use of four transmitters allows for greater specificity and accuracy. The determined location is relative to the vehicle and can be determined as a coordinate (x, y, z) relative to the vehicle. At step 640, in accordance with a determination that the location complies with the command location, the auxiliary device performs the command. The command may be to perform a particular function such as turn on a heated arm rest, turn on lights in a rear footwell, unlock a roof box, output visual content on a display etc. The location may comply with the command location if the location matches the command location. For example, the location is (x4, y4, z4) and the command location is (x4, y4, z4). The location may not comply with the command location if the location does not match the command location. For example, the location is (x7, y2, z3) and the command location is (x4, y4, z4). The method 600 may have some degree of allowance built in to account for measurement error. If the auxiliary device determines a location within a certain distance of the command location, the auxiliary device may still perform the command. The allowance may be such that the location may comply with the command location when the location is within the proximity of the command location. For example, the location complies with the command location when the location is within a range of values comprising the command location. This provides for a certain degree of measurement uncertainty thus enabling an auxiliary device to act on a command even if the location does not precisely comply with the command location. If the location does not comply with the command location, the auxiliary device can forgo performing the command as the command is intended for an auxiliary device at a different location. In one example, the auxiliary device is a roofbox. The roofbox is located on top of the vehicle in a known location. In the case of a roofbox, the command would be to either lock or unlock the roofbox. The command could be triggered by a user providing an input instructing the roofbox specifically to be locked / unlocked. Alternatively, the command could be triggered alongside an instruction to lock / unlock the vehicle. In this way, a single triggering event can instruct the locks on the vehicle as well as the lock on the roofbox. The use of the command location enables a user to swap roofboxes from a first roofbox to a second roofbox. As both roofboxes would be located in the same known position on the vehicle, the auxiliary device location is the same regardless of the particular roofbox. As such, changing roofboxes does not require any change to the command or command location. Furthermore, as the command is only performed if the location of the auxiliary device complies with the command location, a roofbox located, for example, on the floor of a garage would not perform a command from the vehicle as the command location would not comply with the auxiliary device location. For example, the command may be to unlock the roofbox and the command location may be (x6, y6, z7). A roofbox located on the vehicle will have a location of (x6, y6, z7) and therefore unlock whereas a roofbox located on the garage floor may have a location of (x9, y9, z9) and therefore will not unlock. The method 600 can optionally also comprise determining a geographical location of the vehicle and optionally determining if the command is permitted for the geographical location. The geographical location can be determined using known location techniques such as using GPS. In accordance with a determination that the command is not permitted forthe geographical location, the auxiliary device forgoes performing the command. In this way, the vehicle is prevented from providing functions which are not permitted in certain regions, regardless of the fact that the vehicle was instructed to perform the command. For example, a user may provide an input to requestthat a dash cam is turned on. However, the vehicle may determine that it is in a geographical location in which dash cams are not permitted and therefore the auxiliary device forgoes performing the command. Figure 7 illustrates a vehicle 700 according to an embodiment of the invention. The vehicle 700 may comprise the communication system 100 of Figure 1, and the auxiliary device 200 of Figure 2. The vehicle 700 may be an automotive vehicle. The vehicle 700 may be a hybrid electric vehicle having an electric machine and an internal combustion engine both arranged to drive the wheels of the vehicle 700, or may be a battery electric vehicle powered by an electric machine only, or may be a vehicle powered by an internal combustion engine only. In some cases, the vehicle 700 may have multiple electric machines arranged to drive the wheels. The vehicle 700 may also be a mild hybrid electric vehicle (MHEV) or a plug-in hybrid electric vehicle (PHEV). It should be understood that the location of the communication system 100 and the auxiliary device 200 shown in Figure 7 is purely illustrative. Similarly, whilst one communication system 100 and one auxiliary device 200 is shown, it should be understood that any number of communication systems 100 and auxiliary devices 200 can be implemented. It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application.

Claims

1. An auxiliary device for a vehicle, the auxiliary device comprising a receiver and one or more processors collectively configured to:receive at least one signal, via a wireless communication protocol, from each of a plurality of transmitters, wherein at least one of the received signal comprises one or more instructions comprising a command and a command location;calculate a distance of the auxiliary device from each of the plurality of transmitters based on a time of flight measurement for the signal received from each of the plurality of transmitters wherein said signal comprises an indication of a transmission time;determine a location of the auxiliary device relative to the vehicle based on the calculated distance from each of the plurality of transmitters; andin accordance with a determination that the location complies with the command location, perform the command.

2. The auxiliary device of claim 1, further configured to:determine a geographical location of the vehicle;determine if the command is permitted for the geographical location; andin accordance with a determination that the command is not permitted for the geographical location, forgo performing the command.

3. The auxiliary device of claim 1 or 2, configured to receive the at least one signal from each of four or more transmitters.

4. A communication module for controlling an auxiliary device for a vehicle, the communication module configured to be connected to an Electronic Control Unit and comprising a transmitter and one or more processors collectively configured to:receive data signals from the vehicle;convert the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location; andtransmit the one or more instructions and a transmission time to the auxiliary device using a wireless communication protocol.

5. A system comprising a plurality of communication modules for controlling an auxiliary device for a vehicle according to claim 4.

6. The system of claim 5, further comprising one or more auxiliary devices according to any one of claims 1 to 3.

7. The system of any of claims 5 or 6, wherein the one or more instructions and the transmission time are received within the same signal, or wherein the one or more instructions and the transmission time are received within different signals.

8. The system of any of claims 5 to 7, wherein the transmission time is received via ultrawideband and the one or more instructions are transmitted via Bluetooth.

9. A vehicle comprising the system of any of claims 5 to 8.

10. A method of controlling an auxiliary device associated with a vehicle, the method comprising: receiving at the auxiliary device, via a wireless communication protocol, one or more instructions from a plurality of transmitters, wherein the one or more instructions comprise a command and a command location;calculating a distance of the auxiliary device from each of the plurality of transmitters based on a time of flight measurement for a signal received from each of the plurality of transmitters, wherein said signal comprises a transmission time;determining a location of the auxiliary device relative to the vehicle based on the calculated distances from each of the plurality of transmitters; andin accordance with a determination that the location matches the command location, performing the command.

11. The method of claim 10, further comprising:determining a geographical location of the vehicle;determining if the command is permitted for the geographical location; andin accordance with a determination that the command is not permitted for the geographical location, forgo performing the command.

12. The method of claim 10 or claim 11, comprising receiving the one or more instructions and a respective transmission time from each of four or more transmitters.

13. A method of controlling a communication module, the method comprising: receiving data signals from the vehicle;converting the data signals into one or more instructions, wherein the one or more instructions comprise a command and a command location; andtransmitting the one or more instructions and a transmission time to an auxiliary device using a wireless communication protocol.

14. The method of any of claims 10 to 13, wherein the one or more instructions and the transmission time are received within the same signal, or wherein the one or more instructions and the transmission time are received within different signals.

15. Computer readable instructions which, when executed by a computer, are arranged to perform a method according to any of claims 10 to 14.

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