Vehicle supply equipment apparatus and method

Abstract

Control system for controlling an electric vehicle supply equipment (EVSE) comprises a charging gun 202 connected to the EVSE by a charging cable 206, the control system with processor(s) configured t

Description

TECHNICAL FIELD The present disclosure relates to electric vehicle supply equipment. Aspects of the invention relate to a control system for controlling an electric vehicle supply equipment, to an electric vehicle supply equipment, to a computer-implemented method for controlling an electric vehicle supply equipment and to computer readable instructions. BACKGROUND It is known to provide an electric vehicle supply equipment at a home address, and a vehicle can be connected to the supply equipment and receive charge therefrom to charge an energy store of the vehicle. It is desirable to be able to intelligently control features of the supply equipment. 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, an electronic vehicle supply equipment, a computer-implemented method, and computer-readable instructions as claimed in the appended claims. According to an aspect of the present invention, there is provided a control system for controlling an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the control system comprising one or more processors collectively configured to: receive, as input, a retraction inhibition signal indicative of the charging gun being in a state in which retraction of the cable should be inhibited; determine, in dependence on the retraction inhibition signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. Advantageously, this can help to prevent retraction of the charging cable while it is not in a state appropriate for retraction, such as being held by a user. According to an aspect of the present invention, there is provided a control system for controlling an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the control system comprising one or more processors collectively configured to: receive, as input, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. Advantageously, this can help to prevent retraction of the charging cable while it is being held by a user. Therefore the user does not have to resist the retraction of the cable or retrieve the cable after retraction. 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, as input, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. The charging gun is the component through which the electric vehicle supply equipment connects to a vehicle. The charging gun may comprise a plug or socket for forming an electrical connection with a vehicle. The charging gun may comprise a handle. The charging cable is the component which connects the charging gun to a power supply. The charging cable may comprise one or more conductive wires surrounded by an insulator. The conductive wires may be connected to the charging gun at one end. According to an embodiment, the control system may be such that the charging cable is configured to automatically retract on expiration of a predetermined connection timer, the predetermined connection timer commencing upon determination of release of the charging gun from the electric vehicle supply equipment; and wherein the control system is configured to: determine to inhibit the retraction of the charging cable further in dependence of expiration of the predetermined connection timer. Advantageously, automatic retraction of the charging cable ensures that the cable is not in the way of the user or the vehicle, and the cable is also better protected from damage when it is retracted. Advantageously, putting the automatic retraction on a timer means that the cable is not retracted immediately, allowing a user to, for example, place the charging gun on a surface temporarily without it being immediately retracted. According to an embodiment, the control system may be configured to: receive a release signal indicative of release of the charging gun from the electric vehicle supply equipment; and determine, in dependence on the release signal, to commence the predetermined connection timer. Advantageously, starting the predetermined connection timer in response to a release signal ensures that the if the charging gun is released and not used, it can be retracted in a timely manner. According to an embodiment, the control system may be such that the charging gun comprises an accelerometer, and the control system may be configured to: receive accelerometer signalling from the accelerometer in response to release of the charging gun from the electric vehicle supply equipment; and determine, in dependence on the accelerometer signalling, that the charging gun is being held by a user. Advantageously, an accelerometer can be inserted anywhere in a charging gun and be used to help determine whether the charging gun is being held, since operation of an accelerometer does not depend upon proximity to a part of the user to provide information. The control system may be configured to: receive accelerometer signalling from the accelerometer; and determine, in dependence on the accelerometer signalling, that the charging gun is not being held by a user. The control system may be configured to determine, in dependence upon the accelerometer signalling, an orientation of the charging gun with respect to gravity. The control system may be configured to determine, in dependence upon the accelerometer signalling, a motion of the charging gun. Advantageously, both the orientation and the motion of the charging gun can be used to help determine whether the charging gun is being held by a user. For example, when the charging gun is in at least one predetermined orientation, the control system may determine that the charging gun is being held. In addition, when the charging gun is within a predetermined range of at least one predetermined orientation, the control system may determine that the charging gun is being held. Furthermore, when the charging gun is in motion, the control system may determine that the charging gun is being held. The control system may be configured to receive charging cable extension signalling indicative of the charging cable being extended. The control system may be configured to receive charging cable extension signalling indicative of the charging cable being retracted. Advantageously, charging cable extension signalling can be used to help determine whether the charging gun is being held. For example, when the charging gun is fully retracted, the control system may determine that the charging gun is not being held. According to an embodiment, the control system may be configured to determine one or more of: the charging gun lying on a surface in dependence on accelerometer signalling indicative of the charging gun being oriented in a lying position and charging cable extension signalling indicative of the charging cable being extended; and the charging gun being held by a user in dependence on accelerometer signalling indicative of the charging gun being oriented in a use position and charging cable extension signalling indicative of the charging cable being extended. Advantageously, the control system can therefore differentiate between the gun being held and the gun lying upon a surface. According to an embodiment, the control system may be such that the charging gun comprises a touch sensor, and the control system may be configured to: receive touch sensor signalling from the touch sensor in response to a user being in touch contact with the charging gun; and determine, in dependence on the touch sensor signalling, that the charging gun is being held by a user. Advantageously, a touch sensor can determine whether the charging gun is being held directly, through touch. The control system may be configured to: receive touch sensor signalling from touch sensor; and determine, in dependence on the touch sensor signalling, that the charging gun is not being held by a user. The touch sensor may be a pressure sensor. The touch sensor may be an infrared sensor. The touch sensor may be a passive infrared sensor. The touch sensor may be a capacitive sensor. The touch sensor may be an inductive sensor. The touch sensor may be a resistive touch sensor. The touch sensor may comprise a biometric sensor such as a fingerprint sensor. The touch sensor may be an optical sensor. Where the touch sensor is an optical sensor or an infrared sensor, the control system may determine that a change in sensed electromagnetic radiation indicates that the charging gun is being held. Where the touch sensor is an optical sensor, the control system may determine that a reduction in sensed electromagnetic radiation indicates that the charging gun is being held. According to an embodiment, the control system may be configured to: receive, following inhibition of retraction of the charging cable, a release signal indicative of the user releasing hold of the charging gun; determine, in dependence on the release signal, to permit retraction of the charging cable; and output a retract signal to cause retraction of the charging cable. Advantageously, this can lead to the retraction of the charging cable and charging gun in a prompt manner when the charging gun is released. According to an embodiment, the control system may be configured to permit retraction of the charging cable further in dependence on receipt of disconnection signalling indicative of the charging gun being disconnected from a vehicle. Advantageously, this may assist in retracting the charging gun once charging is completed and the gun is disconnected. According to an embodiment, the control system may be configured to output the retract signal following expiration of a pause period. The pause period may have a predetermined length. The pause period may begin when a release signal indicative of the user releasing hold of the charging gun is received. The pause period may begin when a disconnection signalling indicative of the charging gun being disconnected from a vehicle is received. Advantageously, the charging cable may therefore be retracted shortly after it is released or disconnected, so that it is out the way of the user and the vehicle, and further protected from damage. The control system may be configured to: receive, as input during the pause period, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. In response to the hold signal the pause period may be cancelled or reset. According to an embodiment, the control system is configured to inhibit retraction of the charging cable in dependence on receipt of connection signalling indicative of the charging gun being connected to a vehicle. Advantageously, this may help to prevent retraction of the charging gun during charging and while the gun is connected to a vehicle. The control system may be configured to: receive, as input, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to prevent provision of charge through the charging cable; and output a prevention signal to prevent provision of charge through the charging cable. The control system may be configured to: receive, as input from a vehicle distance sensor, a vehicle distance signal indicative of a distance between the charging gun and a vehicle; determine whether the distance is greater than a vehicle threshold distance; and output an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination. The control system may be configured to: receive, as input from a vehicle distance sensor, a vehicle distance signal indicative of a distance between the charging gun and a vehicle; determine, in dependence on the vehicle distance signal, whether the charging gun is being held; and, if it is determined that the charging gun is being held, output an inhibit signal to inhibit retraction of the charging cable. Advantageously, as the user uses and finishes using the charging gun the distance between the charging gun and a vehicle may change, and this may be used to determine whetherthe charging cable should be retracted. The control system may be configured to determine that the charging gun is being held if the distance between the charging gun and the vehicle is greater than a vehicle threshold distance. The control system may be configured to determine that the charging gun is not being held if the distance between the charging gun and the vehicle is less than the vehicle threshold distance. The control system may be configured to determine that the charging gun is being held if the distance between the charging gun and the vehicle is greater than the vehicle threshold distance and has not been less than the vehicle threshold distance since the charging gun was last released from the electric vehicle supply equipment. The control system may be configured to determine that the charging gun is not being held if the distance between the charging gun and the vehicle is greater than the vehicle threshold distance but has been less than the vehicle threshold distance at least once since the charging gun was last released from the electric vehicle supply equipment. Advantageously, when a user is first deploying the charging cable they may take some time to move it close to the vehicle, and in such a circumstance this embodiment can help to prevent a premature retraction of the cable. The vehicle distance sensor may comprise a wireless transceiver. The vehicle distance sensor may transmit and receive wireless signals from the vehicle, those wireless signals being used to determine a distance between the charging gun and the vehicle. The vehicle distance sensor may be provided in the charging gun. The control system may be configured to: receive, as input from an equipment distance sensor, an equipment distance signal indicative of a distance between the charging gun and another part of the electric vehicle supply equipment; determine whether the distance is greater than an equipment threshold distance; and output an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination. The control system may be configured to: receive, as input from an equipment distance sensor, an equipment distance signal indicative of a distance between the charging gun and another part of the electric vehicle supply equipment; determine, in dependence on the equipment distance signal, whether the charging gun is being held; and, if it is determined that the charging gun is being held, output an inhibit signal to inhibit retraction of the charging cable. Advantageously, as the user uses and finishes using the charging gun the distance between the charging gun and other parts of the electric vehicle supply equipment may change, and this may be used to determine whether the charging cable should be retracted. The another part of the electric vehicle supply equipment may be a housing, a reel or a motor. The control system may be configured to determine that the charging gun is being held if the distance between the charging gun and the another part of the electric vehicle supply equipment is less than an equipment threshold distance. The control system may be configured to determine that the charging gun is not being held if the distance between the charging gun and the another part of the electric vehicle supply equipment is more than the equipment threshold distance. The control system may be configured to determine that the charging gun is not being held if the distance between the charging gun and the another part of the electric vehicle supply equipment is less than the equipment threshold distance but has been greater than the equipment threshold distance at least once since the charging gun was last released from the electric vehicle supply equipment. Advantageously, again when a user is first deploying a charging cable they may take some time to move it far enough to connect to the vehicle, and in such a circumstance this embodiment can help to prevent a premature retraction of the cable. The equipment distance sensor may comprise a sensor arranged to detect how much cable has been released from the electric vehicle supply equipment. For example, the equipment distance sensor may comprise a sensor arranged to detect how many times a reel in the electric vehicle supply equipment has rotated. Alternatively, the equipment distance sensor may comprise a plurality of wireless transceivers provided in the charging gun and the another part of the electric vehicle supply equipment, which communicate in order to determine a distance. The control system may be such that the electric vehicle supply equipment comprises a camera. The control system may be arranged to: received, from the camera, one or more images; determine, in dependence on the one or more images, whether the one or more images show a user holding the charging gun; and output an inhibit signal to inhibit retraction of the charging cable if the one or more images show a user holding the charging gun. Advantageously, a camera may be used to determine whether a user is holding a charging gun without the need for additional sensors in the charging gun. The control system may be configured to retract the charging cable after a maximum hold time, even where a hold signal indicates that the charging cable is still being held. The maximum hold time may begin after the charging gun is released from the electric vehicle supply equipment. A timer timing the maximum hold time may pause or be reset to zero whenever it is detected that the charging gun is connected to a vehicle. Advantageously, this may cause retraction of the charging cable even where a hold signal is erroneous. According to another aspect of the invention, there is provided an electronic vehicle supply equipment comprising: a charging gun; a charging cable connecting the charging gun to the electronic vehicle supply equipment; and a control system as described above. In an embodiment, the invention electronic vehicle supply equipment comprises: a charging gun; a charging cable connecting the charging gun to the electronic vehicle supply equipment; and a control system. The control system comprises one or more processors collectively configured to: receive, as input, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. In an embodiment, the invention electronic vehicle supply equipment may further comprise a retraction mechanism configured to retract the charging cable when extended. The retraction mechanism may comprise a reel configured to wind and stored the charging cable and a motor configured to rotate the reel. An inhibit signal to inhibit retraction of the charging cable from the control system may inhibit the operation of the motor. The retraction mechanism may comprise a housing configured to contain the reel and motor, the housing being configured to retain the charging cable when the charging cable is retracted. The housing may be further configured to contain the charging gun when the charging cable is retracted. Advantageously, the retraction mechanism may enable automatic retraction of the charging cable. According to yet another aspect of the invention, there is provided a computer-implemented method for controlling an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the method comprising: receiving, as input, a hold signal indicative of the charging gun being held by a user; determining, in dependence on the hold signal, to inhibit retraction of the charging cable; and outputting an inhibit signal to inhibit retraction of the charging cable. According to a further aspect of the invention, there is provided computer-readable instructions which, when executed by one or more processors, cause the one or more processors to perform the computer implemented method as described above. In an embodiment, the invention computer-readable instructions are such that, when executed by one or more processors an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the computer-readable instruction cause the one or more processors to: receive, as input, a hold signal indicative of the charging gun being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. 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: Figures 1A, 1B and 1C show electric vehicle supply equipment according to embodiments of the invention; Figure 2 shows a control system according to embodiments of the invention; Figure 3 shows a flow chart showing a method which control systems disclosed herein are configured to perform for controlling an electric vehicle supply equipment according to embodiments of the invention; and Figure 4 shows schematically an example charging gun with example sensors according to embodiments of the invention. DETAILED DESCRIPTION It is known to provide an electric vehicle supply equipment at home address, and a vehicle can be connected to the supply equipment and receive charge therefrom to charge an energy store of the vehicle. Discussion herein of supply of electrical charge to the vehicle should be understood as a supply of electrical charge of an energy storage means of the vehicle e.g. a rechargeable battery. An electric vehicle supply equipment (or simply supply equipment) may be understood to be a “charger” or “home charger”, i.e. an apparatus which can be connected to a vehicle (and the electrical energy storage of that vehicle) for the provision of charge from the supply equipment to the vehicle, to recharge the electrical energy storage. The vehicle may be a battery electric vehicle or a hybrid vehicle, for example. The charging gun is connected by a charging cable to the body of a supply equipment. A charging cable and charging gun are for transferring electricity to the traction battery. The charging cable of the electric vehicle supply equipment has significant length such that the charging cable may be used with electric vehicles of varying configurations, shapes, and sizes and / or extend around obstacles. The charging cable may be stowed in the electric vehicle supply equipment when not in use. The charging cable may be extended, and may be automatically retracted in some circumstances to assist in tidying the charging cable away in the electric vehicle supply equipment. The supply equipment is configured to automatically retract (wind in) the charging cable to stow it away. This automatic retraction may be performed, for example, on detecting that the charging gun has been disconnected from a vehicle, or for example if the charging gun has been released from the body of the supply equipment, and left to hang but has not been connected to anything. There is a problem in the art that, if a user releases the charging gun and extends (winds out) the charging cable, for example with the intention of connecting it to a vehicle to charge the vehicle energy store, but then for some reason the user does not connect the charging gun, the supply equipment may aftera particular time period has passed (e.g. a five minute or 10 minute period) retract the charging cable, and if the user still has the charging gun in their hand this sudden automatic retraction is undesirable. For example, the user may release the charging gun and extend the cable intending to connect the charging gun to the vehicle, but then may be distracted by their phone ringing or notification on the smart phone drawing their attention, or may be distracted by someone calling their name, or any other reason. Examples disclosed herein provide improved supply equipment. Examples disclosed herein aim to overcome problems in the art by determining whether the charging gun, when the charging cable is extended, is suitable to be automatically retracted aftera predetermined time period has passed. For example, if the charging gun is determined to be held by a user, even when the predetermined time period has passed after which the cable would normally be retracted, embodiments of the invention prevent the automatic retraction of the cable because the charging gun is still being held any user’s hand, as this would be undesirable. Figure 1A shows electric vehicle supply equipment 200 according to embodiments of the invention. The electric vehicle supply equipment 200 comprises a control system 100 as discussed in relation to Figure 2. The electric vehicle supply equipment 200 comprises a charging gun 202 which can be connected to an electric vehicle and used to provide electrical charge from the electric vehicle supply equipment 200 to the vehicle (i.e. to a rechargeable energy store of the vehicle). In some examples the electric vehicle supply equipment 200 may comprise an output device 204 such as a display screen or visual indicator to indicate information to a user. The charging gun 202 is connected to the electric vehicle supply equipment 200 by a retractable charging cable 206 (not shown in Figure 1A). The electric vehicle supply equipment 200 may allow for the charging cable to be extended so that the charging gun 202 can be brought over to a vehicle and connected to the vehicle to charge it energy store. The electric vehicle supply equipment 200 may automatically retract the charging cable 206 when it is determined to no longer be in use and to be extended. Examples disclosed herein aim to more intelligently control the automatic retraction of the charging cable, in particular to avoid automatic retraction when it is determined that the charging gun is still being held by a user. The electronic vehicle supply equipment 200 comprises: a charging gun 202; a charging cable connecting the charging gun 202 to the electronic vehicle supply equipment 200; and the control system 100 as disclosed herein. The electronic vehicle supply equipment 200 may further comprise a retraction mechanism 208 configured to retract the charging cable when extended. The retraction mechanism 208 may comprise a reel for winding the charging cable 206 and a motor for rotating the reel. Figures 1B and 1C show a cross section of an electronic vehicle supply equipment according to the invention. In Figure 1B the charging cable 206 and the charging gun 202 are stowed / retracted within a housing 214. In Figure 1C the charging gun 202 is released from the housing 214 and the charging cable 206 is unspooled / extended so that the charging gun 202 can be connected to a vehicle for charging. Figure 2 shows a control system 100 according to embodiments of the invention which is for controlling an electric vehicle supply equipment 200. The control system 100 as illustrated in Figure 2 comprises one controller 110, although it will be appreciated that this is merely illustrative. The control system 100 may comprise a plurality of controllers. The controller 110 comprises processing means 120 and memory means 130. 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 150 of the controller 110. The control system 100 is for controlling an electric vehicle supply equipment 200. The electric vehicle supply equipment 200 comprises a charging gun 202 connected to the electric vehicle supply equipment 200 by a charging cable. It will be appreciated that the charging gun 202 being connected to the electric vehicle supply equipment 200 means the charging gun 202 is connected by the charging cable to the body of the supply equipment 200. The control system 100 comprises one or more processors 120 collectively configured to receive, as input, a hold signal indicative of the charging gun 202 being held by a user; determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable. In this way, retraction of the charging cable can be avoided when it is determined that the charging gun is being held by a user. The charging cable 202 may be configured to automatically retract on expiration of a predetermined connection timer. The predetermined connection timer commences upon determination of release of the charging gun 202 from the electric vehicle supply equipment 200. The control system 100 may be configured to receive a release signal indicative of release of the charging gun from the electric vehicle supply equipment; and determine, in dependence on the release signal, to commence the predetermined connection timer. For example, on detecting that the charging gun 202 has been released from the supply equipment 200, a predetermined connection timer of e.g. 5 minutes, or 10 minutes, may start. The control system 100 is configured to determine to inhibit the retraction of the charging cable further in dependence of expiration of the predetermined connection timer. For example, the predetermined connection timer may provide sufficient time for a user to release the charging gun 202 from the supply equipment, take it to their vehicle, and connected to the vehicle. If the charging gun 202 is released from the supply equipment but is not being used, it is desirable to automatically retract the charging cable and restow the charging gun away since it is not being used. However if the charging gun 202 is still being held by a user, it is desirable to prevent this automatic retraction. When the control system 100 receives a hold signal indicative of the charging gun 202 being held by a user, the control system 100 may be configured to reset or pause the predetermined connection timer. Figure 4 shows schematically a charging gun 202 with connected charging cable 206. The charging gun 202 which may contain, as discussed below, an accelerometer 402, and / or a touch sensor 404. The charging gun 202 may comprise an accelerometer 402. The control system 100 may be configured to receive accelerometer signalling from the accelerometer 402 in response to release of the charging gun from the electric vehicle supply equipment; and determine, in dependence on the accelerometer signalling, that the charging gun is being held by a user. It will be appreciated that determination from the accelerometer signalling that the charging gun 202 is being held provides the hold signal received by the control system 100. The control system 100 may be configured to determine the charging gun 202 is lying on a surface in dependence on accelerometer signalling indicative of the charging gun being oriented in a lying position and charging cable extension signalling indicative of the charging cable 206 being extended. For example the charging gun may have an approximately cylindrical shape whereby one end of the cylindrical-shaped gun connects to the vehicle for charging and the opposite end of the cylindrical shaped gun is connected to the charging cable 206. The charging gun therefore has a longitudinal axis 450 along the length of the cylinder. The accelerometer signalling can indicate that the longitudinal axis 450 is approximately parallel with the level of the ground, which is indicative of the charging gun lying on a surface such as the ground or a table or wall. This is therefore further indicative that the charging gun is not being held. The control system 100 may be configured to determine the charging gun is hanging from the charging cable 206 in dependence on accelerometer signalling indicative of the charging gun being oriented in a lying position and charging cable extension signalling indicative of the charging cable 206 being extended. For example, the charging gun may have a centre of gravity such that when hanging from the charging cable 206 without any other support the longitudinal axis 450 will be at a known angle with respect to gravity. The accelerometer signalling can indicate that the longitudinal axis 450 is at or within some range of the known angle with respect to gravity, which is indicative that the charging gun is hanging from the charging cable 206 and is therefore not being held. The control system 100 may be configured to determine the charging gun being held by a user in dependence on accelerometer signalling indicative of the charging gun being oriented in a use position and charging cable extension signalling indicative of the charging cable 206 being extended. The use position may be, for example, a set of positions whereby the charging gun is held at predefined angles with respect to gravity. The charging gun 202 may have a longitudinal axis 450 along the length of the cylinder. The accelerometer signalling can indicate that the longitudinal axis 450 is approximately perpendicular to the level of the ground and is thus being held by a user as opposed to lying on a surface (or at least is aligned in an upright position commensurate with the user holding the gun in their hand ready to connect it to a vehicle). The use position may be any position in which the charging gun is not lying on a surface or hanging from the charging cable 206. The charging gun 202 in some examples may comprise a touch sensor 404, and wherein the control system may be configured to: receive touch sensor signalling from the touch sensor 404 in response to a user being in touch contact with the charging gun; and determine, in dependence on the touch sensor signalling, that the charging gun is being held by a user. The touch sensor may be any suitable touch sensor configured to detect the presence of the user’s hand in contact with or proximal to the gun. Example such touch sensors include finger print sensors, capacitive proximity sensors, inductive sensors, touchscreen sensors, pressure sensors, optical sensors, infrared sensors, or any such sensor configured to determine a human touch and / or grip of the charging gun. The touch sensor 404 may comprise a pressure sensor located under a deformable cover, the deformable cover forming part of the outside of the pressure sensor. Then, when a user picks up the charging gun 202 the pressure of their grip may deform the deformable cover and apply pressure to the pressure sensor. The deformable cover may be elastically deformable. The deformable cover may comprise a plastic or rubber material. The touch sensor 404 may comprise a biometric sensor such as a fingerprint sensor. Where the touch sensor 404 comprises a biometric sensor, it may further be used to identify a user based on biometric readings. The control system 100 may be configured to determine, based on information received from the biometric sensor, that the user is an authorised user. The control system 100 may be configured to allow charging of a vehicle in the event that a user is determined to be an authorised user, and to not allow charging of the vehicle otherwise. The charging gun 202 may comprise a plurality of touch sensors 404, located at different places on the surface of the charging gun 202. The control system 100 may be configured to: receive, following inhibition of retraction of the charging cable 206, a release signal indicative of the user releasing hold of the charging gun 202; determine, in dependence on the release signal, to permit retraction of the charging cable 206; and output a retract signal to cause retraction of the charging cable 206. In this way the control system 100 can detect that the charging gun 202 is no longer being held by a user and can then act to automatically retract it. The control system 100 may be configured to determine to permit retraction of the charging cable 206 further in dependence on receipt of disconnection signalling indicative of the charging gun being disconnected from a vehicle. Therefore the automatic retraction can recommence not only based on determination that the user is not holding the charging on but also on determining that the charging gun is not connected to a vehicle. The control system may be configured to output the retract signal following expiration of a pause period. The control system 100 may be configured to permit retraction of the charging cable 206 after a further particular time period has passed (e.g. a 15 minute period or a 20 minute period) regardless of whether the hold signal indicates that the charging gun 202 is still being held. Therefore the charging gun may still be eventually retracted, even in the event that the hold signal is erroneous. The control system may be configured to inhibit retraction of the charging cable 206 in dependence on receipt of connection signalling indicative of the charging gun being connected to a vehicle. That is, the control system may prevent automatic retraction of the charging cable 206 when the charging gun 202 is determined to be connected to a vehicle. The control system may inhibit retraction of the charging cable in dependence on receipt of connection signalling indicative of the charging gun being connected to a vehicle even in the event that the particular time period or the further particular time period expire. When the control system 100 receives connection signalling indicative of the charging gun being connected to a vehicle, the control system 100 may be configured to reset or pause the predetermined connection timer. The charging gun 202 may further comprise a vehicle distance sensor 406. The vehicle distance sensor 406 may comprise a wireless transceiver which transmits and receives wireless signals from a vehicle in order to determine a distance between the charging gun 202 and the vehicle. The vehicle distance sensor may comprise a Bluetooth® or NFC device. The vehicle may be fitted with a complementary device. The control system 100 may be configured to: receive, as input from the vehicle distance sensor 406, a vehicle distance signal indicative of a distance between the charging gun and a vehicle; determine whether the distance is greater than a vehicle threshold distance; and output an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination. The control system 100 may determine that the charging gun 202 is being held in dependence upon a distance between the charging gun 202 and a vehicle. For example, the control system 100 may be configured to determine that the charging gun 202 is being held if the distance between the charging gun 202 and the vehicle is greater than a vehicle threshold distance, and determine that the charging gun 202 is not being held if the distance between the charging gun 202 and the vehicle is less than the vehicle threshold distance. The control system 100 may be configured to determine that the charging gun 202 is being held if the distance between the charging gun 202 and the vehicle is greater than the vehicle threshold distance and has not been less than the vehicle threshold distance since the charging gun 202 was last released from the electric vehicle supply equipment 200. The control system 100 may be configured to determine that the charging gun 202 is not being held if the distance between the charging gun 202 and the vehicle is greater than the vehicle threshold distance but has been less than the vehicle threshold distance at least once since the charging gun was last released from the electric vehicle supply equipment. In such embodiments, the user can pick up and hold the charging gun 202 while away from the vehicle but, if the user approaches the vehicle with the charging gun 202, for example to plug it in and then unplug it, and then either places the charging gun 202 away from the vehicle or drives off, the control system 100 will determine that the charging gun 202 is not being held and can then retract the charging gun 202. In an alternative embodiment, the control system may be configured to determine that the charging gun 202 is being held if the distance between the charging gun 202 and the vehicle is less than the vehicle threshold distance, and determine that the charging gun 202 is not being held if the distance between the charging gun 202 and the vehicle is greater than the vehicle threshold distance. This may be desirable depending on user’s style of use of the electric vehicle supply equipment 200. The electric vehicle supply equipment 200 may comprise an equipment distance sensor 210. The equipment distance sensor 210 may detect a distance between the charging gun 202 and another part of the electric vehicle supply equipment, such as the retraction mechanism 208, or a housing. The equipment distance sensor 210 may be a sensor arranged to measure the length of charging cable 206 which is dispensed by the electric vehicle supply equipment 200, for example by measuring rotations of a reel upon which the charging cable 206 is stored in the vehicle supply equipment 200. Alternatively, the equipment distance sensor 210 may comprise transceivers on the charging gun 202 and elsewhere on the electric vehicle supply equipment 200, which send and receive signals in orderto determine a distance between the charging gun 202 and the another part of the electric vehicle supply equipment 200. The equipment distance sensor 210 may comprise one or more Bluetooth® or NFC devices. The control system 100 may be configured to: receive, as input from the equipment distance sensor 210, an equipment distance signal indicative of a distance between the charging gun 202 and another part of the electric vehicle supply equipment 200; determine whether the distance is greater than an equipment threshold distance; and output an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination. The control system may be configured to determine that the charging gun is being held in dependence upon the distance between the charging gun 202 and the another part of the electric vehicle supply equipment 200 and, if it is determined that the charging gun is being held, output an inhibit signal to inhibit retraction of the charging cable. The control system 100 may be configured to determine that the charging gun 202 is being held if the distance between the charging gun 202 and the another part of the electric vehicle supply equipment 200 is less than an equipment threshold distance. The control system 100 may be configured to determine that the charging gun 202 is not being held if the distance between the charging gun 202 and the another part of the electric vehicle supply equipment is more than the equipment threshold distance. The control system 100 may be configured to determine that the charging gun 202 is not being held if the distance between the charging gun 202 and the another part of the electric vehicle supply equipment 200 is less than the equipment threshold distance but has been greater than the equipment threshold distance at least once since the charging gun 202 was last released from the electric vehicle supply equipment 200. Therefore, when a user has taken the charging gun 200 to the vehicle, but subsequently returned it nearer to the electric vehicle supply equipment 200, the control system 100 may determine that the user is finished using the charging gun 202 and is no longer holding it, and may therefore retract the charging cable 206. The electric vehicle supply equipment 200 may comprise a camera 212. The camera 212 may capture images of an environment around the electric vehicle supply equipment. The control system 100 may be arranged to: received, from the camera 212, one or more images; determine, in dependence on the one or more images, whether the one or more images show a user holding the charging gun 202; and output an inhibit signal to inhibit retraction of the charging cable 206 if the one or more images show a user holding the charging gun 202. The camera 212 may have other uses for example as a security device to identify a person who interferes with the electric vehicle supply equipment 200 or a vehicle which is located near the electric vehicle supply equipment 200. Figure 3 shows a flow chart showing a computer-implemented method 300 which control systems 100 disclosed herein are configured to perform for controlling an electric vehicle supply equipment 200. The method 300 may be performed by one or more processors executing computer-readable instructions. The method is for controlling an electric vehicle supply equipment 200, the electric vehicle supply equipment 200 comprising a charging gun 202 connected to the electric vehicle supply equipment 200 by a charging cable 206. The method 300 comprises, in step 302, receiving, as input, a hold signal indicative of the charging gun 202 being held by a user. The method 300 comprises, in step 304, determining, in dependence on the hold signal, to inhibit retraction of the charging cable 206. The method 300 comprises, in step 306, outputting an inhibit signal to inhibit retraction of the charging cable 206. The control system 100 may receive further signals and may either inhibit retraction of or retract the charging cable 206 based upon the further signals. For example, where sensors indicate that the charging gun 202 and the charging cable 206 were released from the housing 214 of the electric vehicle supply equipment 202, and then indicate that the charging gun 202 was held but is subsequently idle, i.e. does not move, for greater than a maximum idle time, the control system 100 may cause the charging cable 206 to be retracted. Signals from any one the sensors discussed above may be received by the control system 100, and in response to those 5 signals meeting predefined criteria the control system 100 may pause or reset a retraction timer. When the retraction timer expires, i.e. when the timer reaches a predetermined value, the control system 100 may cause the charging cable 206 to be retracted. The electric vehicle supply equipment 200 may comprise a plurality of different sensors to provide information 10 which may be used to determine the state of the charging gun 202, such as whether the charging gun 202 is being held. For example, the electric vehicle supply equipment may comprise any combination of the accelerometer 402, touch sensor 404, vehicle distance sensor 406 and equipment distance sensor 210 described above. 15 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 an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the control system comprising one or more processors collectively configured to:receive, as input, a hold signal indicative of the charging gun being held by a user;determine, in dependence on the hold signal, to inhibit retraction of the charging cable; and output an inhibit signal to inhibit retraction of the charging cable.

2. The control system of claim 1, wherein the charging cable is configured to automatically retract on expiration of a predetermined connection timer, the predetermined connection timer commencing upon determination of release of the charging gun from the electric vehicle supply equipment; and wherein the control system is configured to:determine to inhibit the retraction of the charging cable further in dependence of expiration of the predetermined connection timer.

3. The control system of claim 2, wherein the control system is configured to:receive a release signal indicative of release of the charging gun from the electric vehicle supply equipment; anddetermine, in dependence on the release signal, to commence the predetermined connection timer.

4. The control system of any preceding claim, wherein the charging gun comprises an accelerometer, and wherein the control system is configured to:receive accelerometer signalling from the accelerometer in response to release of the charging gun from the electric vehicle supply equipment; anddetermine, in dependence on the accelerometer signalling, that the charging gun is being held by a user.

5. The control system of claim 4, wherein the control system is configured to determine one or more of: the charging gun lying on a surface in dependence on accelerometer signalling indicative of the charging gun being oriented in a lying position and charging cable extension signalling indicative of the charging cable being extended; andthe charging gun being held by a user in dependence on accelerometer signalling indicative of the charging gun being oriented in a use position and charging cable extension signalling indicative of the charging cable being extended.

6. The control system of any preceding claim, wherein the charging gun comprises a touch sensor, and wherein the control system is configured to:receive touch sensor signalling from the touch sensor in response to a user being in touch contact with the charging gun; anddetermine, in dependence on the touch sensor signalling, that the charging gun is being held by a user.

7. The control system of any preceding claim, wherein the control system is configured to:receive, following inhibition of retraction of the charging cable, a release signal indicative of the user releasing hold of the charging gun;determine, in dependence on the release signal, to permit retraction of the charging cable; and output a retract signal to cause retraction of the charging cable.

8. The control system of claim 7, wherein the control system is configured to determine to permit retraction of the charging cable further in dependence on receipt of disconnection signalling indicative of the charging gun being disconnected from a vehicle.

9. The control system of claim 7 or claim 8, wherein the control system is configured to output the retract signal following expiration of a pause period.

10. The control system of any preceding claim, wherein the control system is configured to inhibit retraction of the charging cable in dependence on receipt of connection signalling indicative of the charging gun being connected to a vehicle.

11. The control system of any preceding claim, wherein the control system is configured to:receive, as input from a vehicle distance sensor, a vehicle distance signal indicative of a distance between the charging gun and a vehicle;determine whether the distance is greater than a vehicle threshold distance; andoutput an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination.

12. The control system of any preceding claim, wherein the control system is configured to:receive, as input from an equipment distance sensor, an equipment distance signal indicative of a distance between the charging gun and another part of the electric vehicle supply equipment;determine whether the distance is greater than an equipment threshold distance; andoutput an inhibit signal to inhibit retraction of the charging cable in dependence upon the determination.

13. An electronic vehicle supply equipment comprising:a charging gun;a charging cable connecting the charging gun to the electronic vehicle supply equipment;a retraction mechanism configured to retract the charging cable when extended; and the control system of any preceding claim.

14. A computer-implemented method for controlling an electric vehicle supply equipment, the electric vehicle supply equipment comprising a charging gun connected to the electric vehicle supply equipment by a charging cable, the method comprising:receiving, as input, a hold signal indicative of the charging gun being held by a user;determining, in dependence on the hold signal, to inhibit retraction of the charging cable; and outputting an inhibit signal to inhibit retraction of the charging cable.5 15. Computer-readable instructions which, when executed by one or more processors, cause the one ormore processors to perform the method according to claim 14.

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