Apparatus and method for visual alert of a vehicle occupant

Abstract

Aspects of the present invention relate to a control system or controlling a light projector of a vehicle. The control system comprises one or more processors collectively configured to: receive an ab

Description

TECHNICAL FIELD The present disclosure relates to a control system and method for controlling a light projector of a vehicle. Aspects of the invention relate to a control system, to a system, to a vehicle, to a method, and to computer readable instructions. BACKGROUND If a child, pet, or other occupant is left unattended in a vehicle, it can be a problem, for example by the occupant panicking, or potentially suffering ill health through heat stroke. 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 computer-implemented method, and a computer readable medium as claimed in the appended claims. According to an aspect of the present invention there is provided a control system for controlling a visual output device of a vehicle, the control system comprising one or more processors collectively configured to: receive an abandoned occupant signal indicative an abandoned occupant detected inside the vehicle; and control, in dependence on the abandoned occupant signal, the visual output device to output an image indicative of detection of the occupant inside the vehicle. Advantageously, if an occupant is detected as being abandoned in the vehicle, the visual output device can provide a visual indicator to attract the attention of people nearby the vehicle to the vehicle, and the abandoned occupant can receive assistance. According to an aspect of the present invention there is provided a control system for controlling a light projector of a vehicle, the control system comprising one or more processors collectively configured to: receive an abandoned occupant signal from an occupant presence sensor, the abandoned occupant signal indicative of detection of an occupant left inside the vehicle; and control, in dependence on the abandoned occupant signal, the light projector to operate in an occupant alert mode whereby the light projector projects an image indicative of detection of the occupant inside the vehicle, the light projector projecting the image onto a surface external to the vehicle. Advantageously, if an occupant is detected as being abandoned in the vehicle, the light projector of the vehicle can provide a visual indicatorto attract the attention of people nearby the vehicle to the vehicle, and the abandoned occupant can receive assistance. The occupant presence sensor may comprise one or more of: a visual sensor (e.g. a camera), a pressure sensor, a movement sensor, an audio sensor, and a temperature sensor. The abandoned occupant signal may be indicative of an abandoned child, an abandoned animal, or an abandoned adult. The light projector may be configured to operate in plural modes, the plural modes comprising at least the occupant alert mode; and a default mode, wherein the light projector operating in the default mode projects a default non-occupant-indicative image onto the surface external to the vehicle. The light projector may already be part of the vehicle or a retrofitted part and can operate in a default light projector mode, and is configured as described herein to include an additional mode to provide the occupant alert as well and so provide the functionality described herein. Therefore additional or new hardware may not be necessary to provide the occupant alert. The light projector may be configured to operate in the default mode in response to one or more of a door of the vehicle being unlocked; and a door of the vehicle being opened. The default mode operation of the light projector may be to illuminate the area around the vehicle in response to a vehicle door being unlocked, or opened, for example in a dark environment such as an underground car park or at night time. The light projector operating in the default mode may project an image of a logo of the vehicle onto the surface external to the vehicle. Additionally, the default light projection can be customised to the vehicle, providing a personalised user experience, as well as offering functionality to alert of an abandoned occupant. The control system may be configured to control the light projector to operate in the occupant alert mode further in dependence on receipt of a journey completion signal transmitted in response to determination of the end of a drive cycle and closure of a driver’s door of the vehicle. Advantageously, the light projector can operate in the occupant alert mode in response to the end of the drive cycle, indicating the end of journey, and the driver’s door being closed, indicating exiting of the driver from the vehicle, as an additional validation that the situation is indicative of the occupant being abandoned in the vehicle. The control system may be configured to control the light projector to operate in the occupant alert mode further in dependence on expiration of a pause period of a predetermined duration, the pause period commencing on the closure or locking of a driver’s door of the vehicle. Advantageously, the light projector can operate in the occupant alert mode after a period of time following the end of the drive cycle and the driver exiting the vehicle, for example a period of time to allow the driver to move around to the passenger or backseat and help the occupant to exit the vehicle, so the light projector is not activated in the occupant alert mode immediately and to give the driver time to assist the occupant to exit the vehicle. The image indicative of detection of an abandoned occupant inside the vehicle may convey information that an abandoned occupant is detected inside the vehicle. The image may comprise one or more of a pictorial image representative of an abandoned occupant, and a textual message stating the presence of an abandoned occupant. Advantageously, information particular to the determination of an abandoned occupant can be conveyed clearly in the projected image provided by the light projector, to better attract the attention of a passer-by or the nearby driver. The information that an abandoned occupant is detected inside the vehicle may comprise an indication of the occupant type. For example, the pictorial image may comprise an image of the occupant type, e.g. a baby, young child, adult, dog, cat, or small animal. Advantageously, information about the abandoned occupant can be clearly conveyed in the projected image to help attract the attention of the passers-by, for example an image of a baby is likely to attract attention and assistance to assist the abandoned baby. This is as opposed to alert which does not provide any information about the reason for sounding or providing the alert and hence may be ignored, for example, the vehicle detecting the occupant and sounding the vehicle horn and / or flashing the vehicle’s hazard lights, may be ignored as it may be mistaken for an erroneous vehicle security alarm being triggered as if to indicate an attempted unauthorised entry. The control system may be configured to: receive an abandonment time signal indicative of a time of detection of the occupant being left inside the vehicle; determine an abandonment duration in dependence on the time of detection and a current time; if the abandonment duration is below a predetermined abandonment duration threshold, control the light projector to operate in a first occupant alert mode to project a first image; and if the abandonment duration is at or above the predetermined abandonment duration threshold, control the light projector to operate in a second occupant alert mode to project a second image different from the first image. Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned. This is in line with the regulations for providing an alert in response to a suspected abandoned child. The light projector may provide a more noticeable or more urgent warning when operating in the second occupant alert mode when the abandonment duration is above the abandonment time threshold. For example in a first occupant alert mode, an image of a child may be projected, and in the second occupant alert mode, the image of the child may be projected with an additional message stating “child abandoned” and / or a symbol representing urgency, such as an exclamation mark. The control system may be configured to receive an abandonment time signal indicative of a time of detection of the occupant left inside the vehicle; and determine an abandonment duration in dependence on the time of detection and a current time. The abandoned occupant signal may comprise a time of detected abandonment. The determined output image may comprise an indication of one or more of the time of detected abandonment and the duration of abandonment of the occupant. Advantageously, the length of time for which the occupant has been detected as being abandoned may be indicated in the signal provided by the light projector, to assist a passerby in understanding the situation and perform an appropriate response, for example calling out for the driver, or calling the emergency services. In the first occupant alert mode, the control system may be configured to control the light projector to project an image in a first dominant colour. In the second occupant alert mode, the control system may be configured to control the light projector to project an image in a second dominant colour. Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned. This is in line with the regulations for providing an alert in response to a suspected abandoned child, for example. For example in the first occupant alert mode the image may be projected with white light, but in the second occupant alert mode the image may be projected in a colour associated with danger or a warning, such as red. The projected image may comprise an animation, and the control system may be configured to: determine, in dependence on the abandoned occupant signal, one or more of: an alert image representative of an abandoned occupant; a textual message representative of the abandoned occupant; an alert colour indicative of the abandoned occupant; and an alert animation indicative of the abandoned occupant; and control the light projector to project the image indicative of detection of an abandoned occupant inside the vehicle. The image comprising one or more of the alert image, textual message, alert colour, and alert animation. Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned in different ways. The control system may be further configured to control, in dependence on the abandoned occupant signal, a further alert element to operate in a further occupant alert mode whereby the further alert element outputs a further alert indicative of detection of the occupant inside the vehicle. Advantageously, an additional alert mechanism may also be triggered to supplement the image projected by the light projector. The additional alert mechanism may be of a different nature, such as a sound alert, or may be of the same nature but different mechanism of provision, such as lights emitted by the hazard lights or headlights of the vehicle. The further alert element may be one or more of: an audio output system, a vehicle light, a vehicle horn, an in-vehicle console, and a remote communication device. The further alert may be one or more of: an audio message, vehicle light illumination, vehicle horn sounding, in-vehicle console display output, and a message output by the external communication device. In response to receipt of one or more a door unlocking signal indicative of a vehicle door being unlocked, and a door opening signal indicative of a vehicle door being opened, the control system may be configured to control the light projector to cease operation in the occupant alert mode. Advantageously, the image projected by the light projector may be switched off in response to the vehicle being unlocked and / or a door opened, as this is representative of someone returning to the vehicle and accessing it, to assist the abandoned occupant. The control system may be further configured to: receive an ambient light signal indicative of an ambient light level in the environment of the vehicle; determine, in dependence on the ambient light signal, a light projector brightness level, wherein the light projector operating at the light projector brightness level projects, onto the surface external to the vehicle, the image indicative of detection of the abandoned occupant inside the vehicle at a visible brightness level; and control the light projector to project the image indicative of detection of the abandoned occupant inside the vehicle at the determined light projector brightness level. Advantageously, the light may be projected at a brightness commensurate with the ambient light levels, so that a visible alert can be projected, while not unnecessarily using up power projecting an image at a higher brightness than necessary, for example if the environment is dark. Therefore the alert may be provided in a way which does not unnecessarily use up power of the vehicle, to allow the alert to be provided for longer, and to help avoid the vehicle, if it is a battery electric vehicle and the battery power powers the vehicle as well as light projector, from running out of power. The light projector may be configured to project the image at a resolution of 1080p (i.e. 1920 x 1080 pixels) or greater. The light projector may be configured to project the image at a brightness between 0.001 lux and 10 lux. Advantageously, the light projector is able to project a range of images at high enough resolution for a clear meaningful message to be conveyed in the projected image, and is able to project an image at a brightness which is sufficient to be seen in daytime as well as in a dark environment e.g. at nighttime or adjust the brightness according to the environment for e.g. different brightness levels for daytime and night time. In an aspect there is provided a system comprising: any control system disclosed herein; and a light projector. Optionally, the system may further comprise an occupant presence sensor. Advantageously, a light projector may be controlled by a control system as above. The system may also include the occupant presence sensor so that the system is able to detect an abandoned occupant and provide an alert that there is an abandoned occupant. The light projector may be operable to project a plurality of images. Advantageously, the light projector may already be present as part of the vehicle and be used for other purposes, such as illuminating the environment around vehicle e.g. for ease of access in the dark environment, and so additional hardware is not required to put the invention into effect. The light projector may be configured to project the image on a floor on which the vehicle is located. The light projector may be located on a door of the vehicle. Optionally, the light projector may be located on a mirror e.g. a wing mirror. Advantageously, the light projector may be a puddle light and illuminate the ground in the environment of the vehicle, to assist navigating in the environment around the vehicle. The light projector may comprise: a first light projector unit located on a first door of the vehicle, optionally on a mirror of the first door; and a second light projector unit located on a second door of the vehicle, the second door laterally opposite the first door; optionally on a mirror of the second door. Advantageously, the light projector may be a puddle light on a door wing mirror, and illuminate the ground in the environment of the vehicle, to assist navigating in the environment around the vehicle. In an aspect of the present invention, there is provided a vehicle comprising any control system disclosed herein or any system disclosed herein. In an aspect of the present invention, there is provided a computer-implemented method for controlling a light projector of a vehicle, the method comprising: receiving an abandoned occupant signal from an occupant presence sensor, the abandoned occupant signal indicative of detection of an occupant left inside the vehicle; and controlling, in dependence on the abandoned occupant signal, the light projectorto operate in an occupant alert mode whereby the light projector projects an image indicative of detection of the occupant inside the vehicle, the light projector projecting the image onto a surface external to the vehicle. In an aspect of the present invention, there are provided computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform any method disclosed herein. In an aspect of the present invention, there is provided a computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of any method disclosed herein. Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in anyway and / or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and / or incorporate any feature of any other claim although not originally claimed in that manner. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a vehicle according to an embodiment of the invention; Figure 2 shows a control system according to an embodiment of the invention; Figure 3 shows a control system configured to account for a pause period according to an embodiment of the invention; Figure 4 shows a control system configured to operate in plural occupant alert modes according to an embodiment of the invention; Figure 5 shows a control system configured to account for ambient light according to an embodiment of the invention; Figure 6 shows a system according to an embodiment of the invention; and Figure 7 shows a method according to an embodiment of the invention. DETAILED DESCRIPTION If a child, pet, or any other occupant is left unattended in a vehicle it can be a problem. An attempt to alert the driver (if nearby the vehicle) or other passer-by by, for example, the vehicle detecting the occupant and sounding the vehicle horn or flashing the vehicle’s hazard lights risks, may be ignored as it may be mistaken for an erroneous vehicle security alarm being triggered as if to indicate an attempted unauthorised entry. There is a European New Car Assessment Programme (NCAP) implementation aimed towards improving safety for children who may be left unintentionally in a vehicle, for example by a distracted or tired parent. Even if the child (or in other examples, a pet) is left in a vehicle for a short while, it can cause distress and health issues such as heat-stroke and in extreme cases, death. It is an aim of the present invention to provide an improved system and method of indicating the presence of an occupant left in a vehicle who may be unable to signal for help or exit the vehicle themselves. Examples aim to make use of existing hardware to provide specific visual signalling of the occupant detected within the vehicle and to draw the attention of the driver and / or passers-by in an improved way. For example, by displaying an indicator which specifically shows that a child or pet is left within the vehicle may be more likely to encourage intervention and assisting the occupant to safety than a more generic alert of flashing vehicle hazard lights and / or sounding the vehicle horn. A vehicle 100 in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figure 1. As shown in Figure 1, the vehicle 100 is a land-going i.e. wheeled vehicle, and the vehicle may be any vehicle in which there may be an occupant other than the driver present and which may have a light projector 250 (i.e. a light / image output device). It should be noted that the present invention is not limited to the vehicles already having a light projector and in case the vehicle does not have an in-built light projector, the light projector can be retrofitted to the vehicle The vehicle 100 shown in Figure 1 is a passenger vehicle having a plurality of doors and seats therein, although embodiments of the invention may be used with other types of the vehicle. The light projector 250 of the vehicle 100 is shown operating in an occupant alert mode, and so is projecting light 252 which forms an image 254 indicative of detection of the occupant inside the vehicle. The projected image 254 is projected onto a surface external to the vehicle 100, in this case, the floor. The light projector 250 may be configured to project the image at a resolution of 1080p (i.e. 1920 x 1080 pixels) or greater, though in other examples the light projector may have a different resolution. The light projector may be configured to project the image at a brightness between 0.001 lux and 10 lux. Advantageously, the light projector is able to project a range of images at high enough resolution for a clear meaningful message to be conveyed in the projected image. Further, the light projector is able to project an image at a brightness which is sufficient to be seen in daytime as well as in a dark environment e.g. at night time. The light projector 250 may be operable to project a plurality of images, for example, a logo of the vehicle 100, and an image 254 indicative of detection of the occupant inside the vehicle. The different images may be projected dependent on a mode of operation of the light projector 250. In vehicles already with a light projector 250 which can cause images to be displayed e.g. for ease of access in the dark environment, advantageously, the light projector 250 may be configured for the purposes of providing an occupant alert image 254. In such vehicles, additional hardware is not required to put the invention into effect as the existing light projector 250 can be reconfigured for the purposes of providing an alert of an abandoned occupant in the vehicle. As shown in Figure 1, the light projector 250 may be configured to project the image 254 on a floor on which the vehicle 100 is located. The light projector 250 may be located on a door of the vehicle. Optionally, the light projector may be located on a mirror, e.g. a wing mirror, as illustrated. The light projector 250 may be a puddle light, which can illuminate the ground in the environment of the vehicle 100 to assist navigating in the environment around the vehicle. Figure 1 shows a light projector 250 on one wing mirror of the vehicle 100 as an example. In some examples, the light projector 250 may comprise: a first light projector unit located on a first door of the vehicle (e.g. on a mirror of the first door), and a second light projector unit located on a second door of the vehicle (e.g. on a mirror of the second door). The second door (e.g. a front passenger door) may be laterally opposite the first door (e.g. a driver’s door). Figure 2 illustrates a control system 200 according to an embodiment of the invention. The control system 200 is for controlling a light projector 250 of a vehicle 100 as in Figure 1. The control system 200 may comprise one or more controllers 210; in the example shown there is one controller 210. The controller 210 as illustrated in Figure 2 comprises processing means 212 and memory means 214. The processing means 212 may be one or more electronic processing device or processors which operably executes computer-readable instructions. The memory means 214 may be one or more memory device or memory. The memory 214 is electrically coupled to the processing means or processor 212. The memory 214 is configured to store instructions, and the processor 212 is configured to access the memory 214 and execute the instructions stored thereon. The memory 214 may also store data for operation by a process executing on the processor 212. It will be understood that the controller 210 may be implemented by more than one processor 212 and memory 214. The controller 210 comprises an input means 216 and an output means 218. The input means 216 may comprise an electrical input 216 of the controller 210. The output means 218 may comprise an electrical output of the controller 210. The control system 200 is configured to receive an abandoned occupant signal 220 from an occupant presence sensor. In Figure 2, the input 216 is arranged to receive the abandoned occupant signal 220. The abandoned occupant signal 220 is indicative of detection of an occupant left inside the vehicle. The occupant presence sensor may comprise a visual sensor such as a camera. There may be an image processor module configured to receive images captured by the visual sensor and image recognition to determine if there is an occupant and, if so, whether the occupant appears to be an adult, a child, an animal, or any other occupant. The occupant presence sensor may comprise a pressure sensor, which may be configured to detect a pressure and / or variations in pressure applied to a seat of the vehicle and determine whether there is an occupant presenton the seat, and / or whetherthe occupant as an adult, child, an animal, or other occupant. The occupant presence sensor may comprise a movement sensor which may detect movement within the vehicle and determine whether there is an occupant present on the seat, and / or whether the occupant is an adult, child, an animal, or any other occupant. The occupant presence sensor may comprise an audio sensor, and / or a temperature sensor. Other occupant presence sensors may be envisaged which are able to determine the presence of an abandoned occupant in the vehicle. The abandoned occupant signal may be indicative of an abandoned child, an abandoned animal, or an abandoned adult. The control system 200 is configured to control, in dependence on the abandoned occupant signal 220, the light projector 250 to operate in an occupant alert mode, whereby the light projector 250 is controlled to project an image indicative of detection of the occupant inside the vehicle. The light projector 250 projects the image onto a surface external to the vehicle, such as the floor. The control system 200 may output a light projector operation signal 230 to cause the light projector 250 to project the image indicative of detection of the occupant inside the vehicle. In Figure 2, the output means 218 may be arranged to provide the output signal 230 to the light projector 250. Advantageously, if an occupant is detected as being abandoned in the vehicle 100, the light projector 250 of the vehicle 100 can provide a visual indicator to attract the attention of people nearby the vehicle 100 to the vehicle 100, and the abandoned occupant can receive assistance. The light projector 250 may be configured to operate in plural modes. The plural modes may comprise at least the occupant alert mode, and a default mode. The light projector 250 operating in the default mode projects a default non-occupant-indicative image onto the surface external to the vehicle. The default image may be, for example, a uniform pool of light, a logo or image representative of the vehicle, or other default image. The light projector 250 may be configured to operate in the default mode in response to one or more of a door of the vehicle being unlocked; and a door of the vehicle being opened. The default operation of the light projector may be to illuminate the area around the vehicle in response to a vehicle door being unlocked, or opened, for example in a dark environment such as an underground car park at night time. Advantageously, the light projector 250 may already be part of the vehicle 100 and can be configured to operate in a default light projector mode, and is configured as described herein to include an additional mode to provide the occupant alert as well. Therefore additional or new hardware may not be necessary to provide the occupant alert functionality described herein. The control system 200 may be configured to control the light projector 250 to operate in the occupant alert mode further in dependence on receipt of a journey completion signal transmitted in response to determination of the end of a drive cycle and a driver departing the vehicle. That is, the light projector 250 can operate in the occupant alert mode after it is determined that the vehicle has completed a journey and the driver has exited the vehicle or the driver door has opened and closed after the end of the drive cycle. Accounting for these further factors may be advantageous in determining that a remaining occupant in the vehicle is an abandoned occupant because it indicates the vehicle is no longer being driven and that the driver is not present in the vehicle. The control system 200 may be configured to control the light projector 250 to operate in the occupant alert mode further in dependence on receipt of signalling indicating opening and closing of a driver’s door of the vehicle. This may take place in the middle of a journey and without the end of a drive cycle, in some examples. Further, the light projector 250 can operate in the occupant alert mode after it is determined that an occupant has entered the vehicle and closed the door as well as after receiving the abandoned occupant signal. For example, a parent may unlock a vehicle in preparation for loading the vehicle before a journey such as a holiday or a day trip, and a child may enter the vehicle without the parent being aware. Accounting for the operation of the vehicle doors as well as receipt of the abandoned occupant signal may be advantageous in determining the presence of an occupant in the vehicle who may need assistance, or who should not be unsupervised in the vehicle, and that the driver or person in charge of the vehicle should be aware of. The image 254 indicative of detection of an abandoned occupant inside the vehicle may convey information that an abandoned occupant is detected inside the vehicle. For example, the image 254 may comprise a pictorial image representative of an abandoned occupant, and / or a textual message stating the presence of an abandoned occupant. In examples where the type of occupant is determined, for example a child or a dog, then the image may indicate that it is a child, or a dog, which has been detected as abandoned in the vehicle. Advantageously, information particular to the determination of an abandoned occupant can be conveyed clearly in the projected image provided by the light projector, to better attract the attention of a passer-by or the nearby driver. A passerby may be more likely to take notice and action that a baby has been left in a vehicle on seeing the projected image of a baby or a message stating “baby in vehicle”, in contrast to simply seeing flashing hazard lights on a vehicle. Figure 3 shows a control system 200 which is further configured to account for a pause period 302. It may be appropriate to allow the driver a short period of time to assist any occupants out of the vehicle 100 before a determination is made that the occupant has been abandoned. The control system 200 in this example is configured to control the light projector 250 to operate in the occupant alert mode further in dependence on expiration of a pause period of a predetermined duration. The pause period 302 commences on the closure or locking of a driver’s door of the vehicle for example (and this information may be indicted to the control system 200 by a signal 304 indicative of the driver departing the vehicle). That is, the control system 200 may receive the abandoned occupant signal 220, and may wait until the expiration of a pause period 302 before providing an output signal 230 to the light projectorto provide an image indicative of detection of an abandoned occupant in the vehicle. Advantageously, a period of time may be considered, to allow the driver to move around to the passenger or backseat and help the occupant to exit the vehicle, so the light projector is not activated in the occupant alert mode immediately and give the driver time to assist the occupant to exit the vehicle. Figure 4 shows a control system configured to operate in plural occupant alert modes. It may be advantageous to provide different types of alert depending on the context of determining that an occupant has been abandoned in the vehicle 100. For example, the length of time since the occupant has been determined to have been abandoned may be detected and used to cause different images to be projected dependent on the length of time. As another example, the current temperature fore.g. of a vehicle or ambient temperature, may be detected / measured and may be taken into account when controlling the light projector, for example to indicate a risk of heat stroke if the temperature is above the threshold temperature. It will be appreciated that other contextual factors may be detected and used to determine what type of visual output is provided by the light projector. The control system 200 as shown in Figure 4 is configured to receive an abandonment time signal 402 indicative of a time of detection of the occupant being left inside the vehicle. The abandoned occupant signal 220 is also received as before. In some examples the abandoned occupant signal 220 may comprise the time of detected abandonment 402. The control system 200 can determine (404) an abandonment duration in dependence on the time of detection 402 and a current time. If the abandonment duration is below (408) a predetermined abandonment duration threshold, the control system 200 controls the light projector 250 to operate in a first occupant alert mode to project a first image. If the abandonment duration is at or above (406) the predetermined abandonment duration threshold, the control system 200 controls the light projector 250 to operate in a second occupant alert mode to project a second image different from the first image. Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned. The light projector 250 may provide a more noticeable or more urgent warning when operating in the second occupant alert mode when the abandonment duration is above the abandonment time threshold. Some examples are described below but others may be envisaged. In the first occupant alert mode, the control system 200 may be configured to control the light projector 250 to project an image in a first dominant colour, such as amber or yellow. In the second occupant alert mode, the control system may be configured to control the light projector to project an image in a second dominant colour, such as red (or another colour or colour combination associated with urgency or danger). Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned. The determined output image 254 may comprise an indication of the time of detected abandonment, and / or the duration of abandonment of the occupant in some examples. Advantageously, the length of time for which the occupant has been detected as being abandoned may be indicated in the information provided by the light projector, to assist a passerby in understanding the situation and perform an appropriate response, for example calling out for the driver, or calling the emergency services. The projected image 254 may comprises an animation. The control system 200 may be configured to determine, in dependence on the abandoned occupant signal 220, an alert image representative of an abandoned occupant; a textual message representative of the abandoned occupant; an alert colour indicative of the abandoned occupant; and / or an alert animation indicative of the abandoned occupant. The control system 200 may then control the light projector 250 to project the image 254 indicative of detection of an abandoned occupant inside the vehicle wherein the image comprises the alert image, textual message, alert colour, and / or alert animation. Advantageously, the nature of the alert can be escalated dependent on the time that the occupant has been detected as being abandoned in different ways. In some examples, there may be one or more other elements which are configured to provide an indication of an abandoned occupant. The control system 220 may be configured to control, in dependence on the abandoned occupant signal 220, a further alert element to operate in a further occupant alert mode, whereby the further alert element outputs a further alert indicative of detection of the occupant inside the vehicle. Advantageously, an additional alert mechanism may also be triggered to supplement the image projected by the light projector. It may be that in a first occupant alert mode, the light projector 250 is controlled to provide an alert, and in the second occupant alert mode, one or more additional alerts are provided by other alert element(s). The additional alert mechanism may be of a different nature, such as an audio alert (e.g. a horn or other audio warning), or may be of the same nature but different mechanism of provision, such as lights emitted by the hazard lights or headlights of the vehicle. The use of a further alert element may be used to escalate the provided warning in dependence on the length of time of abandonment (or other factor affecting the urgency with which the vehicle should be attended to assist the occupant, such as external temperature or a determination that all the windows are closed). The further alert element 260 may be operated in the second occupant alert mode for example. In some examples, in response to receipt of a door unlocking signal indicative of a vehicle door being unlocked, and / or in response to receipt of a door opening signal indicative of a vehicle door being opened, the control system 200 may be configured to control the light projector 250 to cease operation in the occupant alert mode. These signals are indicative of a return to the vehicle by the driver or other authorised user able to unlock the vehicle and assist the occupant(s). Figure 5 shows a control system 200 configured to account for ambient light. The control system 200 in this example is configured to receive an ambient light signal 510 indicative of an ambient light level in the environment of the vehicle. The control system 200 can then determine (502), in dependence on the ambient light signal 510, a light projector brightness level. The light projector 250 operating at the light projector brightness level will project, onto the surface external to the vehicle, the image indicative of detection of the abandoned occupant inside the vehicle at a visible brightness level. The control system 200 is configured to then control the light projector (via a control signal 230) to project the image indicative of detection of the abandoned occupant inside the vehicle at the determined light projector brightness level. In this way a visible alert can be projected, while not unnecessarily using up power projecting an image at a higher brightness than necessary. Figure 6 shows a system 600 which comprises any control system 200 as disclosed herein, and a light projector 250. In some examples as noted above there may be two light projectors 250, 270, for example one on each wing mirror of the vehicle. The system 600 may further comprise an occupant presence sensor 610, such as a camera, pressure sensor, movement sensor, temperature sensor, or other sensor configured to detect the presence of an occupant. The system 600 may comprise one or more further alert elements 260 as discussed above. Figure 7 shows a method 700 which may be performed by the control system 200 or the system 600 described above. The method 700 is a computer-implemented method 700 for controlling a light projector 250 of a vehicle 100. The method 700 comprises at step 702, receiving an abandoned occupant signal from an occupant presence sensor, the abandoned occupant signal indicative of detection of an occupant left inside the vehicle. At step 704, controlling, in dependence on the abandoned occupant signal, the light projector to operate in an occupant alert mode whereby the light projector projects an image indicative of detection of the occupant inside the vehicle, the light projector projecting the image onto a surface external to the vehicle. Also covered in this disclosure are computer readable instructions which, when executed by one or more processors (e.g. the processor 212 of Figure 2), cause the one or more processors to perform the method 700 or any method disclosed herein. Also covered in this disclosure is a computer readable medium (e.g. a non-transient medium) comprising computer readable instructions that, when executed by a processor (e.g. the processor 212 of Figure 2), cause performance of the method 700 or of any method disclosed herein. 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 light projector of a vehicle, the control system comprising one or more processors collectively configured to:receive an abandoned occupant signal from an occupant presence sensor, the abandoned occupant signal indicative of detection of an occupant left inside the vehicle; andcontrol, in dependence on the abandoned occupant signal, the light projector to operate in an occupant alert mode whereby the light projector projects an image indicative of detection of the occupant inside the vehicle, the light projector projecting the image onto a surface external to the vehicle.

2. The control system of claim 1, wherein the light projector is configured to operate in plural modes, the plural modes comprising at least:the occupant alert mode; anda default mode, wherein the light projector operating in the default mode projects a default non-occupant-indicative image onto the surface external to the vehicle.

3. The control system of claim 1 or claim 2, wherein the control system is configured to control the light projector to operate in the occupant alert mode further in dependence on expiration of a pause period of a predetermined duration, the pause period commencing on the closure or locking of a driver’s door of the vehicle.

4. The control system of any preceding claim, wherein the control system is configured to:receive an abandonment time signal indicative of a time of detection of the occupant being left inside the vehicle;determine an abandonment duration in dependence on the time of detection and a current time;if the abandonment duration is below a predetermined abandonment duration threshold, control the light projector to operate in a first occupant alert mode to project a first image; andif the abandonment duration is at or above the predetermined abandonment duration threshold, control the light projector to operate in a second occupant alert mode to project a second image different from the first image.

5. The control system of any preceding claim, wherein the control system is further configured to:control, in dependence on the abandoned occupant signal, a further alert element to operate in a further occupant alert mode whereby the further alert element outputs a further alert indicative of detection of the occupant inside the vehicle.

6. The control system of any preceding claim, further configured to:receive an ambient light signal indicative of an ambient light level in the environment of the vehicle;determine, in dependence on the ambient light signal, a light projector brightness level, wherein the light projector operating at the light projector brightness level projects, onto the surface external to the vehicle, the image indicative of detection of the abandoned occupant inside the vehicle at a visible brightness level; andcontrol the light projector to project the image indicative of detection of the abandoned occupant inside the vehicle at the determined light projector brightness level.

7. A system comprising:the control system of any preceding claim; anda light projector;optionally, wherein the system further comprises an occupant presence sensor.

8. The system of claim 7, wherein the light projector is operable to project a plurality of images.

9. The system of claim 7 or claim 8, wherein the light projector is configured to project the image at a resolution of 1080p or greater.

10. The system of any of claims 7 to 9, wherein the light projector is configured to project the image on a floor on which the vehicle is located.

11. The system of any of claims 7 to 10, wherein the light projector is located on a door of the vehicle, optionally on a mirror.

12. The system of claim 11, wherein the light projector comprises:a first light projector unit located on a first door of the vehicle, optionally on a mirror of the first door; anda second light projector unit located on a second door of the vehicle, the second door laterally opposite the first door; optionally on a mirror of the second door.

13. A vehicle comprising the control system of any of claims 1 to 6, or the system of any of claims 7 to 12.

14. A computer-implemented method for controlling a light projectorof a vehicle, the method comprising: receiving an abandoned occupant signal from an occupant presence sensor, the abandoned occupant signal indicative of detection of an occupant left inside the vehicle; andcontrolling, in dependence on the abandoned occupant signal, the light projector to operate in an occupant alert mode whereby the light projector projects an image indicative of detection of the occupant inside the vehicle, the light projector projecting the image onto a surface external to the vehicle.

15. A computer readable medium comprising computer readable instructions that, when executed by a processor, cause performance of the method of claim 14.s

Images