Controlling a heating system for a vehicle sensor

Abstract

A control system 100 for controlling a heating system (195, Fig. 2b) for a sensor (190, Fig. 2b) of a vehicle (200, Fig 2b), the control system 100 comprising one or more processors 120 collectively configured to receive a first input signal 160 indicative of a first user interaction with the vehicle and output in response thereto a first control signal 170 to the heating system (195, Fig. 2b) to heat the sensor (190, Fig. 2b) for a first time period; The processors 120 are further configured to determine whether a second input signal 160 indicative of a second user interaction with the vehicle is received within the first time period, and output a second control signal 170 to the heating system; If the second input signal 160 is received within the first time period the second control signal 170 controls the heating system (195, Fig. 2b) to continue heating the sensor (190, fig. 2b), and if the second input signal 160 is not received within the first time period the second control signal 170 controls the heating system (195, Fig. 2b) to stop heating the sensor (190, Fig. 2b)

Description

TECHNICAL FIELD The present disclosure relates to controlling a heating system for a vehicle sensor. Aspects of the invention relate to a control system, a system, a vehicle, a method, and to computer readable instructions. BACKGROUND It is known that certain sensors on a vehicle require a period of pre-heating in order to operate accurately. However, this pre-heating period can cause undesirable delays in starting the vehicle. Additionally, pre-heating a sensor for extended periods can drain the vehicle battery. 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 a control system, a system, a vehicle, a method and to computer readable instructions as claimed in the appended claims. This disclosure provides a technique for pre-heating a sensor of a vehicle. The technique involves outputting a control signal to a heating system of the vehicle to heat the sensor based on a user interaction with the vehicle. The disclosure provides a control system for controlling the heating system, wherein the control system is configured to receive an input signal indicative of one or more driver interactions with the vehicle, and output, in response to the input signal, a control signal to heating system to heat the sensor for at least a first time period. The control system may also be configured to determine, in dependence on the input signal, the at least a first time period for operating the heating system to heat the sensor. According to an aspect of the invention, there is provided a control system for controlling a heating system for a sensor of a vehicle. The control system comprises one or more processors collectively configured to receive a first input signal indicative of a first user interaction with the vehicle, and output, in response to the first input signal, a first control signal to the heating system to heat the sensor for a first time period. The one or more processors are further collectively configured to determine whether a second input signal indicative of a second user interaction with the vehicle is received within the first time period, and output a second control signal to the heating system, wherein if the second input signal is received within the first time period the second control signal controls the heating system to continue heating the sensor, and if the second input signal is not received within the first time period the second control signal controls the heating system to stop heating the sensor. Certain sensors on a vehicle require a period of pre-heating in order to operate accurately. However, this pre-heating period can cause undesirable delays in starting the vehicle. Additionally, pre-heating the sensor for extended periods can drain the vehicle battery. By receiving an input signal indicative of a first user interaction with the vehicle, outputting a control signal to heat the sensor for a first time period in response to the first user interaction, and then deciding whether to continue heating beyond the first time period or to stop heating the sensor depending on whether the user interacts with the vehicle for a second time within that first time period (thus indicating that the vehicle will soon be started and operation of the sensor will be required), unnecessary depletion of the vehicle battery charge is avoided, whilst also ensuring that the sensor is suitably pre-heated and thereby mitigating undesirable delays in starting the vehicle. The control 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: receive a first input signal indicative of a first user interaction with the vehicle; output, in response to the first input signal, a first control signal to the heating system to heat the sensor for a first time period; determine whether a second input signal indicative of a second user interaction with the vehicle is received within the first time period; and output a second control signal to the heating system, wherein if the second input signal is received within the first time period the second control signal controls the heating system to continue heating the sensor, and if the second input signal is not received within the first time period the second control signal controls the heating system to stop heating the sensor. Optionally, the second user interaction with the vehicle is different than the first user interaction with the vehicle. In this way, a greater level of confidence that the user is ready to start the vehicle is provided. For example, it may be more indicative that a user is ready to start the vehicle if they open a door of the vehicle (first interaction) and then plug in their seatbelt (second interaction), compared to if they open a door of their vehicle and then re-open the door, which may suggest the user has left and returned to the vehicle and is still no closer to starting the vehicle. Optionally, a user interaction comprises one or more of: a change in a lock status of the vehicle; a change in a closure status of the vehicle; a fastening of a driver’s seatbelt; a key location within the vehicle; a user starting the vehicle; and a detection of a user in a driver’s seat of the vehicle. Optionally, the detection of a user in a driver’s seat of the vehicle may be provided by a pressure sensor in the driver’s seat and / or a camera within the vehicle that is configured to detect a user sat in the driver’s seat. In this way, the presence of a user in the driver’s seat can be reliably detected, indicative of an increased likelihood that the user intends to start the vehicle imminently. Optionally, the one or more processors are collectively configured to determine, in response to the first input signal, the first time period for operating the heating system to heat the sensor. Optionally, the one or more processors are collectively configured to determine, in response to the second input signal, a second time period for operating the heating system to heat the sensor. Optionally, the second time period is less than the first time period. In this way, if the user’s interactions with the vehicle indicate that the user is closer to starting the vehicle, heating of the sensor is continued, but for a smaller time period in order to minimise the depletion of the vehicle battery charge as a result of heating the sensor. Optionally, the one or more processors are collectively configured to determine whether a third input signal indicative of a third user interaction with the vehicle is received within the second time period; and output a third control signal to the heating system to: continue heating the sensor if the third input signal is received within the second time period, and to stop heating the sensor if the third input signal is not received within the second time period. In this way, heating of the sensor only continues if it is likely that the user will start the vehicle within the second time period. For example, if a user unlocks the vehicle (first interaction) and opens a door (second interaction) in the first time period, but does not interact further with the vehicle during the second time period (e g., by fastening their seatbelt), then heating of the sensor is stopped in order to preserve the vehicle battery charge and prevent damage to the sensor. If no further interaction with the vehicle occurs after a maximum time limit, no further heating of the sensor will occur until the vehicle is finally started, to thereby protect the sensor and preserve battery charge. In such cases, a message may be output to a human machine interface of the vehicle to inform the user that there may be delay starting the vehicle whilst the sensor is heated. Optionally, the one or more processors are collectively configured to, after receiving the first input signal: receive a state of charge signal indicative of a state of charge of a battery of the vehicle used to provide power to the heating system; determine, in dependence on the state of charge signal, whether the state of charge of the battery of the vehicle is below a state of charge threshold; and output a further control signal to the heating system to prevent heating of the sensor if the state of charge of the battery is below the state of charge threshold. In this way, the state of charge of the battery is maintained and risk of damage to the battery is mitigated. In such cases, a message may be output to a human machine interface of the vehicle to inform the user that there may be delay starting the vehicle. The further control signal may sometimes be referred to as an “override signal”. Optionally, the one or more processors are collectively configured to: receive a temperature signal indicative of an ambient temperature; determine, in dependence on the temperature signal, whether the ambient temperature is below an ambient temperature threshold; and output a further control signal to the heating system to prevent heating of the sensor if the ambient temperature is below the ambient temperature threshold. Cold temperatures may affect a battery’s ability to hold its charge. By preventing the heating of the sensor in cold temperatures until the battery temperature has increased, the battery charge may be preserved for other key uses, such as powering the starter motor of the engine. In such cases, a message maybe outputtoahuman machine interface of the vehicle to inform the user that there may be delay starting the vehicle. Optionally, the control system is for controlling the heating system for the sensor of the vehicle prior to cranking an engine of the vehicle. In this way, delays in cranking the engine of the vehicle are mitigated. Optionally, the sensor is exposed to ambient conditions. Optionally, the sensor is an exhaust sensor of the vehicle, optionally wherein the sensor is a universal exhaust gas oxygen, UEGO, sensor. By preheating an exhaust sensor of a vehicle, accurate combustion control may be provided, thereby allowing the vehicle engine to be in closed loop control as soon as possible after cold cranking. According to another aspect of the invention, there is provided a system comprising the control system as described above and a heating system for a sensor of a vehicle. According to a yet another aspect of the invention, there is provided a vehicle comprising the system as described above or the control system as described above. According to a further aspect of the invention, there is provided a method for controlling a heating system for a sensor of a vehicle, the method comprising: receiving a first input signal indicative of a first user interaction with the vehicle; outputting, in response to the first input signal, a first control signal to the heating system to heat the sensor for a first time period; determining whether a second input signal indicative of a second user interaction with the vehicle is received within the first time period; and outputting a second control signal to the heating system, wherein if the second input signal is received within the first time period the second control signal controls the heating system to continue heating the sensor, and if the second input signal is not received within the first time period the second control signal controls the heating system to stop heating the sensor. According to a still further aspect of the invention, there are provided computer readable instructions which, when executed by a computer, are arranged to perform a method as described above. 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 is a block diagram showing a control system according to an embodiment of the present invention; Figure 2a is a schematic illustration of a vehicle according to an embodiment of the present invention; Figure 2b is a schematic illustration of a rear-view of the vehicle of Figure 2a; Figure 3 is a first flowchart showing operations performed by the control system of Figure 1 according to an embodiment of the present invention; and Figure 4 is a second flowchart showing operations performed by the control system of Figure 1 according to an embodiment of the present invention. DETAILED DESCRIPTION With reference to Figure 1, there is illustrated a control system 100 for a vehicle. The control system 100 comprises one or more controller 110. The controller 110 comprises processing means 120 and memory means 1130. The processing means 120 may be one or more electronic processing device 120 which operably executes computer-readable instructions. The memory means 130 may be one or more memory device 130. The memory means 130 is electrically coupled to the processing means 120. The memory means 130 is configured to store instructions, and the processing means 120 is configured to access the memory means 130 and execute the instructions stored thereon. The controller 110 comprises an input means 140 and an output means 150. The input means 140 may comprise an electrical input 140 of the controller 110. The output means 150 may comprise an electrical output signal 170 of the controller 110. The input means 140 is arranged to receive a user interaction signal 160 from one or more sensors of the vehicle. The user interaction signal 160 is an electrical signal which is indicative of one or more user interactions with the vehicle, including but not limited to a change in a lock status of the vehicle, a change in closure status of the vehicle, a fastening of a driver’s seatbelt, a key location within the vehicle, a user starting the vehicle, and a detection of a user in a driver’s seat of the vehicle (e g., detected by a seat pressure sensor or camera), or any other suitable user interaction with the vehicle. The output 150 is arranged to output one or more control signals 170 to a heating system of the vehicle to control the heating of a sensor of the vehicle. Optionally, the sensor to be heated may be an exhaust sensor of the vehicle, and further optionally, a universal exhaust gas oxygen (UEGO) sensor. Conventionally, a UEGO sensor is heated by exhaust gases, leading to a period of time before the UEGO sensor is sufficiently heated, causing the vehicle engine to be in open loop control and thus controlling air-to-fuel ratios based on maps stored in an engine control module of the vehicle 200. Conversely, by pre-heating the UEGO sensor by other means to a required operating temperature, the vehicle engine can be placed into closed loop control as soon as possible after cold cranking of the engine occurs, allowing the engine control module to have enhanced combustion control. The input means 140 may be optionally arranged to receive a state of charge signal 162 from a battery sensor of the vehicle. The state of charge signal 162 maybe an electrical signal which is indicative of a state of charge of a battery of the vehicle, wherein said battery is operable to provide power to the heating system (among, for example, other components of the vehicle 200). The input means 140 may be further optionally arranged to receive a temperature signal 164 from a temperature sensor of the vehicle. The temperature signal 164 may be an electrical signal which is indicative of the ambient temperature in and around the vehicle. The output means 150 may also be optionally arranged to output a control signal 175 to a human machine interface (HMI) to provide information to the user, as will be described further below. Figure 2a illustrates a vehicle 200 according to an embodiment of the present invention. The vehicle 200 comprises a control system 100 as illustrated in Figure 1. The vehicle 200 may one or more user input sensors located within, and / or on an exterior surface of, the vehicle 200, the one or more user input sensors being configured to detect a user interaction with the vehicle 200 and provide an input signal indicative of a user interaction with the vehicle 200 to the input means 140 of the control system 100. In one illustrative example, the vehicle 200 may have a user input sensor 180 configured to detect a vehicle a change in a closure status of the vehicle, e.g., when a user opens a door of the vehicle 200. Alternatively, or additionally, the vehicle 200 may have user input sensors configured to detect an unlock signal provided when a user unlocks the vehicle 200 using a key, key fob or mobile device, a fastening of a driver’s seatbelt, a location of a key or key fob within the vehicle 200, a user starting the vehicle 200, and a presence of user in a driver’s seat of the vehicle 200 (e.g., as detected by a seat pressure sensor or camera device). As described above, the output 150 of the control system 100 is arranged to output a control signal 170 to control a heating system of the vehicle 200 to heat a sensor of the vehicle 200. The heating system may draw electrical energy from a battery of the vehicle (e.g., a 12V battery of the vehicle 200) to heat the sensor. The sensor may be a sensor that is exposed to ambient conditions. For instance, Figure 2b illustrates a rear-view of the vehicle 200 of Figure 2a and shows an example where the sensor is an exhaust gas sensor 190 located within an exhaust system 185 of the vehicle 200, the exhaust gas sensor 190 being heated by a heating system 195. In one illustrative example, the sensor is a universal exhaust gas oxygen (UEGO) sensor 190 that may be sealed within the exhaust system 185 of the vehicle 200 and is configured to measure an air-to-fuel ratio based on exhaust gases in the exhaust system 185. The sensor 190 may be exposed to ambient conditions within the exhaust system 185. Such UEGO sensors may require a period of pre-heating before the vehicle 200 is started (i.e., before cranking of the engine of the vehicle 200) in order to accurately measure the air-to-fuel ratio. However, such a need for a period of pre-heating can lead to undesirable delays in cranking the engine of the vehicle 200, such that there is a perceivable delay between the driver requesting to start the vehicle (e.g., by pressing a start button or turning the key) and the vehicle being ready to drive. Figure 3 is a flowchart 300 according to an embodiment of the invention. The flowchart 300 illustrates steps performed by the control system 100 in controlling a heating system 195 for a sensor 190 of the vehicle 200. In particular, the memory means 130 may comprise computer-readable instructions which, when executed by the processor 120, perform the method 300 according to an embodiment of the invention. At step 310, the processing means 120 of the control system 100 is configured to receive a first input signal indicative of a first user interaction with the vehicle 200. The first user interaction is received as input signal 160 at the input means 140 of the control system 100 and comprises data indicating that a user has interacted with the vehicle in some way. The input signal 160 may be received from a user input sensor 180 mentioned above, and may be indicative of one or more of a change in a closure status of the vehicle (i.e., a user opening the door of the vehicle 200), a change in lock status of the vehicle (i.e., a user unlocking the vehicle 200 using their key, key fob or mobile device), a fastening of a driver’s seatbelt, a location of a key or key fob within the vehicle 200, a user starting the vehicle 200, and a presence of user in a driver’s seat of the vehicle 200. At step 320, the processing means 120 is configured to output, in dependence on receipt of the input signal 160 at the input means 140, a first control signal 170 to the heating system 195 to heat the sensor 190 for a first time period. The first time period may be longer than is required to adequately pre-heat the sensor 190, such that the sensor 190 remains in a sufficiently heated state in order to allow for the vehicle 200 to be started without delays to cranking. However, in order to preserve the capacity of the battery of the vehicle 200, heating the sensor 190 for extended periods is undesirable. As an example, the first time period may be three minutes, however, it will be appreciated that the first time period may be any suitable time period depending on the heating requirements of the sensor 190. Optionally, the first time period may be stored in the memory means 130 and be accessed by the processing means 120, for example, upon receipt of the first input signal 160. Optionally, upon receipt of the first input signal 160, the processing means 120 may be configured to determine the first time period, for example, in dependence on the type of user interaction indicated in the first input signal 160. In this respect, certain user interactions may be indicative that the user is closer to starting the vehicle 200 than other interactions. For example, if the first user interaction indicates that the driver’s door has been opened, this may indicate that the user is closer to starting the vehicle 200 than if the first user interaction indicates that a rear door has been opened. As such, the first time period may be determined based on a balance between a likelihood that the user will crank start the vehicle 200 within a given duration after first interacting with the vehicle 200 and a need to preserve the capacity of the battery of the vehicle 200. At step 330, the processing means 120 is configured to determine whether a second input signal 160 indicative of a second user interaction with the vehicle 200 is received within the first time period. Like the first user interaction, the second user interaction may be received as an input signal 160 at the input means 140 of the control system 100 and comprise data indicating that the user has further interacted with the vehicle in some way. The second input signal 160 may be received from a user input sensor 180 mentioned above, and may be indicative of one or more of a change in a closure status of the vehicle, a change in lock status of the vehicle 200, a fastening of a driver’s seatbelt, a location of a key or key fob within the vehicle 200, a user starting the vehicle 200, and a presence of a user in a driver’s seat of the vehicle 200. The second user interaction may be different to the first user interaction. For example, the first user interaction may be indicative of a user opening a door of the vehicle 200, whereas the second user interaction may indicate that a user has placed their key fob (or mobile device) within an interior of the vehicle 200 (e.g., the second input signal 160 may be a signal received from the user’s key fob (or mobile device) when the user has placed their key fob (or mobile device) in a specified location within the vehicle 200). In another example, the second user interaction may indicate that a driver of the vehicle 200 has fastened their seatbelt (e.g., the second input signal 160 may be a signal received from a driver seatbelt sensor when the driver’s seatbelt is fastened). The second user interaction may also be a user sitting in a driver’s seat of the vehicle 200. For example, a camera system may be installed within the vehicle 200, and, upon detecting a user sat in the driver’s seat of the vehicle 200, the camera system may be configured to provide the second user interaction signal 160. Additionally, or alternatively, a sensing system may be provided in the driver’s seat and, upon detecting a user sat in the driver’s seat (e.g., via pressure sensor data), the sensing system may be configured to provide the second input signal 160. In general, the second user interaction being different to the first user interaction is indicative of an increased likelihood that the user intends to start the vehicle 200 imminently. For example, if the first user interaction is a user unlocking the vehicle 200, and the second user interaction is a user placing their key fob within the vehicle 200 or sitting in the driver’s seat of the vehicle 200, then it is probable that the user intends to start the vehicle 200 imminently. This is in comparison to, for example, a situation where the user unlocks and then locks the vehicle 200, or opens and then closes a door (in which case the first and second user interaction are the same type of interaction), suggesting that the user is less likely to start the vehicle 200 imminently, and may have in fact left the vehicle 200 altogether. At step 340, the processing means 120 is configured to output a second control signal 170 to the heating system 195 of the vehicle 200. If the second input signal 160 is received within the first time period (i.e., following the first user interaction), the second control signal 170 controls the heating system 195 to continue heating the sensor 190. However, if the second input signal 160 is not received within the first time period, the second control signal 170 controls the heating system 195 to stop heating the sensor 190. If the second input signal 160 is received within the first time period, then it can be deduced that there is a reasonable likelihood that the user intends to start the vehicle 200 imminently, and as such, that the avoidance of a delay in cranking the engine by continuing to heat the sensor 190 (by outputting the second control signal 170 to the heating system 195) justifies the additional power consumption from the vehicle battery. Furthermore, since the heating of the sensor 190 is likely to only continue for a short period of time, such heating is unlikely to cause any damage to the sensor 190. However, if the second input signal 160 is not received within the first time period, then it can be deduced that the likelihood of the user starting the vehicle 200 imminently is relatively low, then the second control signal 170 controls the heating system 195 to stop heating the sensor 190, thereby preserving the charge of the vehicle battery and protecting the sensor 190 from excessive heating. If the second input signal 160 is received within the first time period, the processing means 120 may be configured to determine a second time period for operating the heating system 195 to heat the sensor 190. Given that receiving the second input signal 160 within the first time period is indicative of a user’s intention to start the vehicle 200 imminently, the second time period may be less than the first time period in order to mitigate delays in cranking the engine of the vehicle 200 by continuing to heat the sensor 190 whilst minimising depletion of the vehicle’s battery. As an example, the second time period may be two minutes, however the skilled person would appreciate that the second time period may be any suitable duration that is less than the first time period. Optionally, the second time period may be stored in the memory means 130 and be accessed by the processing means 120, for example, upon receipt of the second input signal 160. Alternatively, upon receipt of the second input signal 160, the processing means 120 may be configured to determine the second time period, for example, in dependence on the type of user interaction indicated in the second user interaction signal 160. As such, if the first user interaction indicated that the driver’s door was opened, and the second user interaction indicates that the driver’s seatbelt has been fastened, it can be deduced that the driver is likely to start the vehicle 200 imminently and thus the sensor 190 will only require continued heating for a short period of time. Conversely, if the second user interaction indicates that a rear door has been opened, it can be deduced that the driver is not likely to start the vehicle 200 soon and thus the sensor 190 is likely to need continued heating for a longer period of time. In some situations, a user may leave and return to the vehicle 200 multiple times over an extended period, for example if making multiple trips to load items into a boot space of the vehicle 200, or if the user returns to their house to retrieve an item that has been forgotten. In such situations, the processing means 120 may be configured to determine whether a third input signal 160, indicative of a third user interaction with the vehicle 200, is received within the second time period. The third user interaction may be any of the examples of user interaction provided previously. In one example scenario, the first user interaction may be a user unlocking the vehicle, the second user interaction may be the user opening a door of the vehicle 200, and the third user interaction may be the user placing their key fob within the vehicle 200. In other words, with each of these user interactions, it becomes increasingly likely that the user intends to start the vehicle 200 imminently. If the third input signal 160 is received within the second time period, then the processing means 120 may output a third control signal 170 to control the heating system 195 to continue heating the sensor 190. The third control signal 170 may control the heating system 195 to continue heating the sensor 190 for a third time period, which may be less than the second time period. In one example, the third time period may be one minute, however the skilled person would appreciate that the third time period may be any suitable duration that is less than the second time period. In the event that the third input signal 160 is not received within the second time period, then the processing means 120 may output a third control signal 170 to the heating system 195 to stop heating the sensor 190. Optionally, the third time period may be stored in the memory means 130 and be accessed by the processing means 120, for example, upon receipt of the third user interaction signal 160. Alternatively, upon receipt of the third input signal 160, the processing means 120 may be configured to determine the third time period, for example, in dependence on the type of user interaction indicated in the third input signal 160. It will also be appreciated that the processing means 120 may be configured to continue receiving user interaction signals 160 and controlling the heating system 195 in dependence thereon, until one or more of the following conditions is met: the user starts the vehicle 200, a control signal 170 is output to the heating system 195 to stop heating the sensor 190 or a maximum time period of heating is reached. A maximum time period may be preset and stored in the memory means 130. If no further user interaction with the vehicle 200 occurs after the maximum time period has elapsed, then no further heating of the sensor 190 will occur until after the vehicle 200 has been started in order to preserve the charge of the vehicle battery and protect the sensor 190 from damage caused by overheating. In such situations, the processing means 120 may be configured to output a control signal 175 to a human machine interface (HMI) of the vehicle 200 to provide a message to a user of the vehicle 200, to inform the user that there will be a delay in starting the vehicle 200. In one example, the maximum time period is twelve minutes. However, the skilled person would appreciate that the maximum time period may be determined on a case-by-case basis depending on the heating requirements of the sensor 190 and the available charge of the vehicle battery. Figure 4 is a flowchart 400 according to an embodiment of the invention. The flowchart 400 illustrates steps performed by the control system 100 in controlling a heating system of the vehicle 200. Steps 310, 320, 330 and 340 are the same as illustrated in Figure 3 and their discussion is not repeated in detail for brevity. However, flowchart 400 illustrates additional step 315 at which the control system 100 is configured to, after receiving the first user interaction signal in step 310, receive a state of charge signal 162 indicative of a state of charge of the vehicle battery used to provide power to the heating system 195. The state of charge signal 162 may be received at the input means 140 of the controller 110. The processing means 120 may be configured to determine, in dependence on the state of charge signal 162, whether the state of charge of the battery of the vehicle 200 is below a state of charge threshold. For example, the processing means 120 may compare the state of charge signal 162 against a state of charge threshold stored in the memory means 130. The state of charge signal 162 may also be received concurrently with the first input signal 160. For example, the state of charge signal 162 may be received at the same time as a user opens a door of the vehicle 200, or unlocks the vehicle 200. In the event that the state of charge signal 162 indicates that the state of charge of the battery is below a state of charge threshold (e.g., 10% charge), the processing means 120 may output, via the output means 150, a further control signal 170 (which may be thought of as an “override signal”) to the heating system 195 to prevent heating of the sensor 190, in order to maintain the state of charge of the battery and mitigate the risk of damage to the battery. In such situations, a message may be conveyed to a user of the vehicle 200, for example, by outputting a control signal 175 to a human machine interface (HMl) of the vehicle 200, to inform the user that there will be a delay in starting the vehicle 200. Conversely, in the event that the state of charge signal indicates that the state of charge of the battery is above the state of charge threshold, then the control system 100 proceeds to step 320. After step 320 (i.e., after the processing means 120 has outputted the first control signal 170 to the heating system 195 to heat the sensor 190 for a first time period), the processing means 120 may be configured to continue to receive (e.g., at periodic intervals) further state of charge signals 162. In the event that any of the further state of charge signals 162 indicate that the state of charge of the battery is below the state of charge threshold, the processing means 120 may output, via the output means 150, a further control signal 170 to the heating system 195 to prevent heating of the sensor 190. Alternatively, or additionally, at step 315, the control system 100 may be configured to, after receiving the first input signal in step 310, receive a temperature signal 164 indicative of an ambient temperature (i.e., the ambient temperature around the vehicle 200). The temperature signal 164 may be received from one or more temperature sensors mounted on the vehicle 200, and may be received at the input means 140 of the controller 110. The processing means 120 may be configured to determine, in dependence on the temperature signal 164, whether the ambient temperature is below an ambient temperature threshold. For example, the processing means 120 may compare the ambient temperature signal 164 against an ambient temperature threshold stored in the memory means 130. The temperature signal 164 may also be received concurrently with the first input signal 160. For example, the temperature signal 164 may be received at the same time as a user opens a door of the vehicle 200, or unlocks the vehicle 200. The temperature signal 164 may also be received concurrently with the state of charge signal 162 mentioned above. In the event that the ambient temperature signal 164 indicates that ambient temperature is below an ambient temperature threshold, the processing means 120 may output, via the output means 150, a further control signal 170 (which maybe thought of as an “override signal”) to the heating system 195 to prevent heating of the sensor 190, in order to mitigate the risk of damage to the battery of the vehicle 200. In such situations, a message may be conveyed to a user of the vehicle 200, for example, by outputting a control signal 175 to a human machine interface (HMI) of the vehicle 200, to inform the user that there will be a delay in starting the vehicle 200. Conversely, in the event that the ambient temperature signal 164 indicates that the ambient temperature is above the ambient temperature threshold, then the control system 100 proceeds to step 320. After step 320 (i.e., after the processing means 120 has outputted the first control signal 170 to the heating system 195 to heat the sensor 190 for a first time period), the processing means 120 may be configured to continue to receive (e.g., at periodic intervals) further ambient temperature signals 164. In the event that any of the further ambient temperature signals 164 indicate that the ambient temperature is below the ambient temperature threshold, the processing means 120 may output, via the output means 150, a further control signal 170 to the heating system 195 to prevent heating of the sensor 190. 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. A control system for controlling a heating system for a sensor of a vehicle, the control system comprising one or more processors collectively configured to:receive a first input signal indicative of a first user interaction with the vehicle;output, in response to the first input signal, a first control signal to the heating system to heat the sensor for a first time period;determine whether a second input signal indicative of a second user interaction with the vehicle is received within the first time period; andoutput a second control signal to the heating system, wherein if the second input signal is received within the first time period the second control signal controls the heating system to continue heating the sensor, and if the second input signal is not received within the first time period the second control signal controls the heating system to stop heating the sensor.

2. The control system of claim 1, wherein the second user interaction with the vehicle is different than the first user interaction with the vehicle.

3. The control system of claim 1 or claim 2, wherein a user interaction comprises one or more of: a change in a lock status of the vehicle; a change in a closure status of the vehicle; a fastening of a driver’s seatbelt; a key location within the vehicle; a user starting the vehicle; and a detection of a user in a driver’s seat of the vehicle.

4. The control system of any preceding claim, wherein the one or more processors are collectively configured to: determine, in response to the first input signal, the first time period for operating the heating system to heat the sensor.

5. The control system of any preceding claim, wherein the one or more processors are collectively configured to: determine, in response to the second input signal, a second time period for operating the heating system to heat the sensor.

6. The control system of claim 5, wherein the second time period is less than the first time period.

7. The control system of claim 5 or claim 6, wherein the one or more processors are collectively configured to:determine whether a third input signal indicative of a third user interaction with the vehicle is received within the second time period; andoutput a third control signal to the heating system to:continue heating the sensor if the third input signal is received within the second time period, and to stop heating the sensor if the third input signal is not received within the second time period.

8. The control system of any preceding claim, wherein the one or more processors are collectively configured to, after receiving the first input signal:receive a state of charge signal indicative of a state of charge of a battery of the vehicle used to provide power to the heating system;determine, in dependence on the state of charge signal, whether the state of charge of the battery of the vehicle is below a state of charge threshold; andoutput a further control signal to the heating system to prevent heating of the sensor if the state of charge of the battery is below the state of charge threshold.

9. The control system of any preceding claim, wherein the one or more processors are collectively configured to:receive a temperature signal indicative of an ambient temperature;determine, in dependence on the temperature signal, whether the ambient temperature is below an ambient temperature threshold; andoutput a further control signal to the heating system to prevent heating of the sensor if the ambient temperature is below the ambient temperature threshold.

10. The control system of any preceding claim, wherein the sensor is exposed to ambient conditions.

11. The control system of any preceding claim, wherein the sensor is an exhaust sensor of the vehicle, optionally wherein thesensor is a universal exhaust gas oxygen, UEGO, sensor.

12. A system comprising the control system of any preceding claim and a heating system for a sensor of a vehicle.

13. A vehicle comprising the system of claim 12 or the control system of claims 1-11.

14. A method for controlling a heating system for a sensor of a vehicle, the method comprising:receiving a first input signal indicative of a first user interaction with the vehicle;outputting, in response to the first input signal, a first control signal to the heating system to heat the sensor for a first time period;determining whether a second input signal indicative of a second user interaction with the vehicle is received within the first time period; andoutputting a second control signal to the heating system, wherein if the second input signal is received within the first time period the second control signal controls the heating system to continue heating the sensor, and if the second input signal is not received within the first time period the second control signal controls the heating system to stop heating the sensor.

15. Computer readable instructions which, when executed by a computer, are arranged to perform a method according to claim 14.13

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