CONTROL SYSTEM FOR A DRIVER ASSISTANCE SYSTEM
TECHNICAL FIELD
The present disclosure relates to a control system for a driver assistance system. Aspects of the invention relate to a control system, a system, a vehicle, and computer readable instructions.
BACKGROUND
It is known to provide features in a vehicle which may provide an alert for a driver who is not in the most appropriate state for driving, such as being fatigued, distracted or unresponsive. For example, if a driver is detected as being in a fatigued or drowsy state, an audio, visual or haptic alert may be provided in response to alert the driver, so the driver may return their attention to driving or perhaps stop for a rest before continuing their journey. Further improvements to vehicle operation in view of a driver's detected state of responsiveness would be beneficial.
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, 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 a driver assistance system of a vehicle. The control system is configured to receive a driver attention level input signal indicative of a level of driver attention to controlling the vehicle, determine whether the level of driver attention is below a driver attention threshold, and, according to whether the determined level of driver attention is above or below the driver attention threshold, output a control signal to control the driver assistance system.
Advantageously, the DAS of the car can be controlled according to the attentiveness of the driver to driving the vehicle.
According to an aspect of the present invention there is provided a control system for controlling a driver assistance system of a vehicle, the control system comprising one or more processors collectively configured to: obtain a driver attention level input signal, the driver attention level input signal indicative of a determined level of driver attention to controlling operation of the vehicle; in dependence on the determined level of driver attention, determine whether the level of driver attention is below a driver attention threshold; and in response to the level of driver attention being determined to be below the driver attention threshold, output a driver assistance system control increase signal, the driver assistance system control increase signal to cause an increase in automatic driver assistance functionality to be provided by the driver assistance system.
Advantageously, the DAS of the car can be controlled to provide more automatic driving assistance if the driver is determined to be inattentive. A driver paying less attention to controlling the vehicle is detected as being less attentive and the DAS is automatically controlled to provide more driving assistance to compensate for the driver's inattentiveness. Automatic driver assistance functionality may be considered to be vehicle control functionality which is automatically activated in response to a determination that the current driver operation of the vehicle would benefit from the driver assistance functionality, to supports operation of the vehicle.
The control system may comprise 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: obtain a driver attention level input signal, the driver attention level input signal indicative of a determined level of driver attention to controlling operation of the vehicle; in dependence on the determined level of driver attention, determine whether the level of driver attention is below a driver attention threshold; and in response to the level of driver attention being determined to be below the driver attention threshold, output a driver assistance system control increase signal, the driver assistance system control increase signal to cause an increase in automatic driver assistance functionality to be provided by the driver assistance system.
Advantageously, the DAS of the vehicle can be controlled in response to input indicative of additional automatic driver support being beneficial due to the attention state of the driver, to provide an output to control the DAS to provide more automatic driving assistance if the driver is determined to be inattentive.
The driver attention level input signal may be further indicative of a determined category of driver attention.
The control system may be further configured to: in dependence on the determined category of driver attention, determine a type of driver assistance to be provided by the driver assistance system to provide the increase in automatic driver assistance functionality; and output the driver assistance system control increase signal to cause the increase in automatic driver assistance functionality according to the determined type of driver assistance to be provided.
Advantageously, the DAS can automatically provide increased driving assistance in a particular way to compensate for the way in which the driver is determined to be inattentive.
The category of driver attention may comprise one or more of: driver drowsiness; driver distraction; and driver unresponsiveness. Driver drowsiness may be indicated by detection that e.g. the driver's eyes are closed or close/open, the driver's head position is tilted forwards or backwards, or the driver's eye gaze is located downwards, indicative of sleep, microsleep or fatigue. Driver distraction may be indicated by detection that e.g. the driver's eye gaze direction is not sufficiently directed to the road ahead or to a region corresponding to a manoeuvre being performed such as in the rear view mirror when reversing, or the driver's eye gaze is directed to a point of distraction such as an infotainment screen or mobile phone. Driver unresponsiveness may be indicated by detection that e.g. the driver is turning the steering wheel later than a predetermined response time; the driver's manoeuvring, braking, accelerating to change the vehicle movement is faster or slower than an predetermined movement change time, or an alcohol level or drug level detected of the driver is indicative of a lower responsiveness than if the driver's alcohol or drug level was zero (or below a respective threshold level).
Advantageously, different categories of driver attention may be responded to in different ways by the DAS. For example, if the driver is determined to be drowsy then automatic lane assistance may be increased to compensate for the drowsy driver being more likely to drift out of lane. For example, if the driver is determined to be distracted or unresponsive then automatic forward braking sensitivity levels may be increased to automatically apply the brakes earlier in detecting an object ahead of the vehicle, to compensate for the distracted driver being more likely to not be observing the road ahead. Other examples include providing additional indicators or alerts to the driver to indicate the operation or increase in operation of a type of assistance provided by the DAS.
The control system may be configured to obtain the driver attention level input signal by receiving the determined level of driver attention from a facial analysis module configured to capture one or more images of a face of the driver and determine, in dependence on the one or more images, the level of driver attention.
Advantageously, facial analysis may be used to determine the attention state of the driver. Facial recognition can determine different attention states of the driver, for example by detecting how long eyelid closures last, and a user's eye gaze direction, to determine a level of sleepiness or distraction of the driver. An increase in DAS activity to automatically control the vehicle can then be provided corresponding to the determined attention state of the driver. As facial recognition techniques evolve, there is scope to determine driver emotions, for example, and increased DAS activity may be provided if the driver is determined to be experiencing an emotion which indicates they are likely to be less attentive, for example, high levels of anger or sadness. Also, there is the potential to determine a possible medical condition of the driver through facial recognition, for example a stroke or fit, and the DAS may be activated correspondingly to provide increased control of the vehicle appropriately in some examples.
The driver attention threshold may be dependent on one or more of whether the vehicle is performing a transfer of control event, and whether the vehicle is performing a minimum risk manoeuvre. "Transfer of control events" may be considered to be a change in the level of vehicle control performed automatically by the vehicle and performed manually by the driver. A "minimum risk manoeuvre" may be considered to be a procedure aimed, at mininsina risks in traffic, which is autornaticaq performed by the system after a transition demand without driver response.
Advantageously, the DAS can automatically provide increased driving assistance in a particular way to compensate for the way in which the vehicle is currently operating. When operating to transfer a control event, for example transitioning from autonomous to manual driving, a high DAS activity level may be appropriate at least until determination that the driver has full control of the vehicle.
The increase in automatic driver assistance functionality to be provided by the driver assistance system may comprise one or more of: lane assistance configured to control the vehicle to be located within a driving lane; forward collision warning provision indicative of a risk of forward collision of the vehicle; speed limit warning provision indicative of a road speed limit at the location of the vehicle; new speed limit notification provision indicative of a road speed limit ahead of the vehicle; and blind spot monitoring provision indicative of the presence of an object in a blind spot of the vehicle.
Advantageously, the DAS can automatically provide increased driving assistance in one or more different ways to most appropriately compensate for the way in which the driver is determined to be inattentive.
The control system may be configured to provide a driver assistance mode indicator signal to a driver output apparatus, the driver assistance mode indicator signal configured to cause the driver output apparatus to provide an indicator to indicate the driver assistance functionality being provided.
Advantageously, the DAS can automatically provide increased driving assistance in one or more different ways to most appropriately compensate for the way in which the driver is determined to be inattentive and the DAS operation can be communicated to the driver so they are aware of the DAS provision being made and the indicator prompts the driver to recognise a change in DAS activity is taking place.
The control system may be configured to: obtain a further driver attention level input signal, the further driver attention level input signal indicative of a further determined level of driver attention to controlling operation of the vehicle; in dependence on the further determined level of driver attention, determine whether the level of driver attention is above the driver attention threshold; and in response to the level of driver attention being determined to be above the driver attention threshold, output a driver assistance system control decrease signal, the driver assistance system control decrease signal to cause an decrease in automatic driver assistance functionality to be provided by the driver assistance system.
Advantageously, the control system can decrease the level of control provided by the DAS when the driver is determined to be more attentive.
The driver assistance system control decrease signal may be configured to cause the decrease in automatic driver assistance functionality to be provided by the driver assistance system, to return the automatic driver assistance functionality to a level of driver assistance functionality provided by the driver assistance system before the increase in driver assistance functionality provided in response to the level of driver attention being determined to be below the driver attention threshold.
Advantageously, the control system can decrease the level of control provided by the DAS when the driver is determined to be more attentive to revert back to the level of control provided by the DAS before the driver attention level was determined to be below the driver attention threshold. In this way the driver inattentiveness may be temporarily compensated for, and "normal" DAS activity resumed once the driver is sufficiently attentive again e.g. puts their phone away.
The driver assistance system may be configured to operate in a plurality of modes, wherein each of the plurality of modes provides a different level of automatic driver assistance functionality in a driver assistance. The control system may be configured to output the driver assistance system control increase signal to cause the driver assistance system to operate in a high assistance mode to thereby cause the increase in automatic driver assistance functionality.
Advantageously, there may be a discrete number of preprogramed modes and increasing the level of control by the DAS means a high level of control is provided. Previously the level of control may have been in a lower mode of control (e.g. a low mode or a custom mode providing less control than the high mode). Using a predetermined set of control modes means the driver may more easily understand how the vehicle is being automatically controlled. Moving the control mode to "high" means there is a predetermined set of control functionality which is activated as a group in response to the driver attention level falling below the driver attention threshold, which may be computationally more efficient than computing and activating a series of separate DAS functionality to particular levels of activity.
In an aspect there is provided a system for a vehicle, the system comprising: any control system disclosed herein; and a driver attention level determination module in communication with the control system, the driver attention level determination module configured to: receive driver attention state input indicative of the attention state of the driver; determine the driver attention level input signal in dependence on the driver attention state; and provide the driver attention level input signal to the control system.
Advantageously, the driver attention level determination module can use input from one or more systems which indicate how attentive the driver is, determine the driver attention level input to provide to the control system, and provide the driver attention level input to the control system to then use it in turn to control the DAS.
The driver attention state input may comprise one or more of: driver facial input obtained from an image capture device, the driver facial input indicative of one or more of: driver facial expression, driver eye gaze direction, driver eyelid position, and eyelid closure duration; and steering wheel contact input obtained from a steering wheel sensor, the steering wheel contact input indicative of the contact of a driver's hand with a steering wheel of the vehicle.
Advantageously, the driver attention level determination module can use input from an image capture device such as a steering wheel mounted driver facing camera or cameras, or a pressure or touch sensor on the steering wheel, for example, and use the input from one or more such devices to determine a driver attention level.
In an aspect there is provided a vehicle comprising any system disclosed herein, or any control system disclosed herein. Advantageously, a vehicle may be fitted with such control systems to provide an improved vehicle able to compensate for driver inattentiveness using the DAS which may usually be found on board the vehicle as a standard component of the vehicle.
In an aspect there is provided a method for controlling a driver assistance system of a vehicle, the method comprising: obtaining a driver attention level input signal, the driver attention level input signal indicative of a determined level of driver attention to controlling operation of the vehicle; in dependence on the determined level of driver attention, determining whether the level of driver attention is below a driver attention threshold; and in response to the level of driver attention being determined to be below the driver attention threshold, outputting a driver assistance system control increase signal, the driver assistance system control increase signal to cause an increase in automatic driver assistance functionality to be provided by the driver assistance system. Advantageously, there is a way to use control the DAS on board the vehicle to compensate for driver attention which does not reach the acceptable threshold for attentiveness without increased DAS activity.
In an aspect there is provided computer readable instructions which, when executed by a computer, are arranged to perform any method disclosed herein. Advantageously, the method may be implemented as computer code, such as a computer on board the vehicle, and operate with existing technology such as driver attention detection elements and DAS elements.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination.
That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
BRIEF DESCRIPTION OF THE DRAWINGS
One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a vehicle according to examples disclosed herein; Figure 2 shows a block diagram of control system according to examples disclosed herein; Figures 3A, 3B 3C each show a control system configured to perform a method according to examples disclosed herein; Figure 4 shows an example of driver attention categories and subsequent control increase signals according to examples disclosed herein; Figure 5 shows example automatic driver assistance functionalities controllable by control increase signals according to examples disclosed herein; Figure 6 shows an example driver attention level determination module and control system according to examples disclosed herein; and Figure 7 shows an example method according to examples disclosed herein.
DETAILED DESCRIPTION
It is known to provide for features in a vehicle which may detect if a driver is in an appropriate state to control the vehicle. In response, an alert may be provided to indicate to the driver that they should improve their attention state and an enhanced level of driver assistance functionality may be provided. For example, if a driver is detected as being in a drowsy state, an audio or visual alert may be provided in response to improve the driver's attention state and be more attentive or perhaps stop for a rest before continuing their journey. During the drowsy state, increased levels of driver assistance functionalities may be provided to increase driving assistance. Further improvements to vehicle operation in view of a driver's detected state of responsiveness would be beneficial.
Examples disclosed herein may provide an improved way to control a Driver Assistance System (DAS) of a vehicle in response to a determined driver state (i.e. attentiveness) of the driver to controlling the vehicle. A Driver Assistance System (DAS), sometimes called an Advanced Driver Assistance System (ADAS), is a system or group of systems which autonomously operate to support control of a vehicle. In this way, the DAS system, which is usually a standard vehicle component (i.e., is not necessarily an additional specific system to be fitted to the vehicle for the examples disclosed to be realised) may be controlled to account for a detected driver attention level to improve the control of the vehicle.
Examples disclosed herein may also account for particular operations during driving which may warrant increased control of the vehicle and thus which may compensate in a targeted way for less appropriate driver attention states that may benefit from increased levels of driver assistance. For example, during a transfer of control event (i.e., when the vehicle is transitioning between two different levels of autonomous control, such as handing full control back to the driver after at least partially autonomous control, or transitioning from full autonomous control to partially autonomous and partial driver control) it may be particularly advantageous to account for driver attentiveness during the process of transferring the control of the vehicle to the driver. As another example, during a minimum risk manoeuvre (e.g. when the vehicle is autonomously brought to a stop) it may be particularly advantageous to account for driver attentiveness to provide increased assistance when the driver may not be fully in control of the driving task.
Examples disclosed herein may also support provision of high levels of DAS functionality during a period of driver inattentiveness, particularly in respect of scenarios which benefits from high levels of vehicle control when the desired vehicle control is determined to be high (for example, during an emergency mitigation process such as determination of an obstacle ahead of the vehicle or a determination of emergency braking being required). If the driver attention level is determined not to meet the high desired vehicle control level, the DAS system may be controlled to compensate for a potentially absent level of driver control to automatically provide control so that together, the driver and DAS control provide the high level of vehicle control desirable in the situation.
Figure 1 shows a vehicle 10 according to examples disclosed herein comprising the systems or control systems discussed below. The vehicle may be fitted with such systems or control systems 100 to provide an improved vehicle able to compensate for driver inattentiveness using the DAS which may commonly be found on board.
With reference to Figure 2, there is illustrated a control system 100 for controlling a DAS of a vehicle 10. The control system 100 is configured to receive a driver attention level input signal 165, for example from a driver attention level determination module 160, and determine whether the level of driver attention is below a driver attention threshold. The control system 110 may then output a control signal 155 to control an DAS 170 according to whether the level of driver attention is above or below the driver attention threshold, e.g. to identify that the driver is fatigued, distracted or unresponsive.
The control system 100 comprises one or more controller 110. The control system comprises one or more processors 120, collectively configured to obtain a driver attention level input signal 165. The driver attention level input signal 165 is indicative of a determined level of driver attention to controlling operation of the vehicle. In dependence on the determined level of driver attention, the control system 100 is configured to determine whether the level of driver attention is below a driver attention threshold. In response to the level of driver attention being determined to be below the driver attention threshold, the control system 100 is configured to output a DAS control increase signal 155. The DAS control increase signal 155 is to cause an increase in automatic driver assistance functionality to be provided by the DAS. Automatic driver assistance functionality may be considered to be vehicle control functionality which is automatically activated and configured in higher sensitivity levels in response to a determination that the current driver operation of the vehicle would benefit from the driver assistance functionality, to supports operation of the vehicle.
The control system 100 as illustrated in Figure 1 comprises one controller 110, although it will be appreciated that this is merely illustrative. 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 input 140 is arranged to receive a driver attention level input signal 165 from a from a driver attention level determination module 160. The driver attention level input signal 165 is an electrical signal which is indicative of determined level of driver attention to controlling operation of the vehicle. The output 150 is arranged to output a DAS control increase signal 155 which is indicative of an increase in automatic driver assistance functionality and is for controlling the DAS 170 to provide the increase in automatic driver assistance functionality provided by the DAS 170.
Figure 3A illustrates a control system 100 such as that described above in relation to Figure 2 configured to perform a method 300 according to an embodiment of the invention. The control system 100 is for controlling a DAS of a vehicle. The control system 100 is configured to obtain 302 a driver attention level input signal 310. The driver attention level input signal 310 is indicative of a determined level of driver attention to controlling operation of the vehicle. The driver attention level input signal 310 may, for example, be obtained from a driver-facing camera, or a computer module configured to receive data from a driver-facing camera and determine a level of driver attentiveness, for example using facial or emotion recognition software.
In dependence on the determined level of driver attention, the control system 100 is configured to determine 304 whether the level of driver attention is below a driver attention threshold. In response to the level of driver attention being determined to be below the driver attention threshold (indicated by a "Y" for yes in Figure 3A), the control system 100 is configured to output a DAS control increase signal 306. The DAS control increase signal 306 is to cause an increase in automatic driver assistance functionality to be provided by the DAS.
Advantageously, the DAS can be controlled to provide more automatic driving assistance if the driver is determined to be inattentive. A driver paying less attention to controlling the vehicle than a predetermined acceptable threshold of attention can be detected, and the DAS is automatically controlled by the control system to provide more driving assistance to compensate for the driver's inattentiveness.
Automatic driver assistance functionality may be considered to be the provision of one or more electronic technologies that assist drivers to perform driving and parking tasks of the vehicle in their control. Automatic driver assistance functionality may be considered to be one or more functions provided by the vehicle to assist the driver in controlling the vehicle, and the one or more functions are provided automatically in response to a sensed condition indicative of the one or more functions causing improvement in the operation of the vehicle.
That is, if a condition of poor steering control is sensed, then driver assistance may be automatically deployed to steer the vehicle to remain in a lane. As another example, if a condition of poor driver reactions to obstacles in the path of the vehicle is sensed, then driver assistance may be automatically deployed to cause the vehicle to provide an indicator to the driver to alert the driver to the presence of the obstacle. The indicator may be provided, compared with no previously provided indicator being provided, if no such indicator was previously provided, or, if such an indicator was previously provided, the indicator may be provided earlier than previously provided. In some examples, the alert could be supplemented with a vehicle intervention. For instance, with the provision of autonomous braking assistance to mitigate a potential collision.
Figure 3B illustrates a control system 100 such as that described above in relation to Figure 2 and Figure 3A configured to perform a method 300 according to an embodiment of the invention, with additional possible functionality and possible connection of the control system 100 to additional elements 400, 410, 200, 510 indicated. Figure 3B shows a system 1000 for a vehicle, the system 1000 comprising any control system 100 as disclosed herein; and a driver attention level determination module 400 in communication with the control system 100. The driver attention level determination module 400 may be part of a larger driver state sensing system 410 such as a facial recognition system or steering wheel-pressure sensing apparatus, for example. This is described in more detail in relation to Figure 6. Also shown in Figure 3B is a driver output apparatus 510 which is configured to provide an indicator to indicate the driver assistance functionality being provided. Also shown in Figure 3B is a DAS 200 which is connected to and at least partially controlled by the control system 100.
Figure 3B shows that, in response to the level of driver attention being determined to be below the driver attention threshold (indicated by a "Y" for yes in Figure 3B), the control system 100 is configured to output a DAS control increase signal 306. Conversely, if the level of driver attention meets, or is above, the driver attention threshold (indicated by a "N" for no in Figure 3B), then in response the control system 100 may be configured to do nothing and return back 308 to the step 302 of obtaining a (further) driver attention level input signal 310. In some examples, if the level of driver attention meets, or is above, the driver attention threshold, then in response the control system 100 may be configured to output a DAS maintain operation signal (not shown) to cause the DAS 200 to maintain the same level of automatic driver assistance functionality provided by the DAS, for example. The control system 100 may return 308 to check the level of driver attention again by obtaining 302 another driver attention level input signal 310 at a later time.
Figure 3B also illustrates that the control system 100 may be configured to obtain the driver attention level input signal 310 by receiving the driver attention level input signal 310 indicative of the determined level of driver attention from a facial analysis module 400. The facial analysis module 400 may be configured to capture one or more images of a face of the driver and determine, in dependence on the one or more images, the level of driver attention. For example, facial recognition technology may be able to determine, from an image of images of the driver's face, head, or upper body, an attention status of the driver and report this to the control system in the driver attention level input signal 310. Facial recognition can determine different attention states of the driver, for example by detecting how long eyelid closures last, and/or a user's eye gaze direction, to determine a level of sleepiness or distraction of the driver, or to determine that the driver does not have the hands on the wheel, or to determine that the driver is not responding to fatigue or distraction alerts. An increase in DAS 200 activity to automatically control the vehicle can then be provided corresponding to the determined attention state of the driver. As facial recognition techniques evolve, there is scope to determine driver emotions, for example, and increased DAS 200 activity may be provided if the driver is determined to be experiencing an emotion which means they are likely to be less attentive to the road, for example, high levels of anger or sadness. Also, there is the potential to determine a possible medical condition of the driver through facial recognition, for example a stroke or fit, and the DAS 200 may be activated correspondingly to provide increased control of the vehicle appropriately. Of course as well as facial recognition, more broadly, image recognition may also be employed, for example to determine hand positioning, head posture, or other indicator of driver attentiveness.
Advantageously, the driver attention level determination module 400 can use input from one or more systems 410 which indicate how attentive the driver is, determine the driver attention level input 310 to provide to the control system 100, and provide the driver attention level input 310 to the control system 100 to then use it in turn to control the DAS 200.
In some examples, as well as controlling the operation of the DAS, there may be an indication of the operation (or change in operation) of the DAS 200 to the driver, so the driver is aware that the vehicle has moved to being automatically operated in a different way. The control system 100 may, as shown in Figure 3B, be configured to provide a driver assistance mode indicator signal 500 to a driver output apparatus 510. The driver assistance mode indicator signal 500 may be configured to cause the driver output apparatus 510 to provide an indicator to indicate the driver assistance functionality being provided. For example, if lane assistance of the DAS 200 is activated, then an icon may be illuminated in the dashboard panel 510 of the vehicle to indicate that lane assistance has been activated to make the driver aware of how the vehicle is operating. As another example, an audio indicator such as a tone, beep, or spoken word indicator, may be provided via an audio output device 510 (e.g. a speaker) inside the vehicle cabin to indicate the change in operation of a DAS, for example, announcing "blind spot sensing activated". Of course other examples and combinations of indicators may be envisaged dependent on the DAS functionality being provided. Advantageously, DAS 200 operation can be communicated to the driver, so they are aware of the DAS 200 provision being made and the indicator prompts the driver to recognise a change in DAS 200 activity is taking place.
Figure 3C illustrates a control system 100 such as that described above in relation to Figure 2, Figure 3A or Figure 3B, configured to perform a method 300 according to an embodiment of the invention, which illustrates that continuous or periodic monitoring of the level of driver attention can take place to adjust the DAS 200 functionality provided according to the level of driver attention determined throughout a journey or drive cycle, for example. The control system 100 is configured to obtain 332 a further driver attention level input signal 330. The further driver attention level input signal 330 is indicative of a further determined level of driver attention to controlling operation of the vehicle. In dependence on the further determined level of driver attention 330, the control system 100 is configured to determine 334 whether the level of driver attention is above the driver attention threshold. The driver may have become more attentive to driving since a previous determination of insufficient attentiveness causing an increase in DAS 200 functionality provided. For example, enabling lane assistance, or providing a voice prompt that blind spot monitoring has been enabled, may cause the driver to become more attentive (e.g. by no longer looking at their phone, or by re-focussing on the road ahead rather than looking at the climate controls or other control device for the vehicle).
In response to the level of driver attention being determined to be above the driver attention threshold, the control system 100 may be configured to output a DAS control decrease signal 336, the DAS control decrease signal 336 to cause a decrease in automatic driver assistance functionality to be provided by the DAS 200. That is, the DAS system may return to the previous settings state in response to the control system, which continues to measure the driver's attention state, determining that the driver has returned to a higher level of attentiveness or lower level of fatigue or responsive to the driving task, for example. Thus, in the event that a previously inattentive driver is later sufficiently attentive (to be detected as having appropriate road attention, fatigue and responsiveness levels, so the level of driver attention is above the driver attention threshold) the DAS 200 functionality provided may be correspondingly reduced. Advantageously, the control system can decrease the level of control provided by the DAS 200 when the driver is determined to be more attentive. In some examples, in response to the level of driver attention being determined to remain below the driver attention threshold, the control system 100 may be configured to provide no DAS control decrease signal 336, or output a DAS maintain operation signal (not shown) to cause the DAS 200 to maintain the same level of automatic driver assistance functionality provided by the DAS, and then return 338 to check the level of driver attention again by obtaining 332 another further driver attention level input signal 330 at a later time.
In some examples, the DAS control decrease signal 336 may be configured to cause the decrease in automatic driver assistance functionality to be provided by the DAS 200, to return the automatic driver assistance functionality to a level of driver assistance functionality provided by the DAS 200 before the increase in driver assistance functionality provided in response to the level of driver attention being determined to be below the driver attention threshold. Advantageously, the control system 100 can decrease the level of control provided by the DAS 200 when the driver is determined to be more attentive (e.g. less fatigued or more responsive) to revert back to the level of control provided by the DAS 200 before the driver's attention state was determined to be less appropriate. In this way the driver's inattentiveness may be temporarily compensated for and "normal" DAS 200 activity resumed once the driver is sufficiently attentive again.
In some examples, the driver may be able to override the system and return the DAS control level to a reduced sensitivity level, to cause the decrease in automatic driver assistance functionality to be provided by the DAS 200. This feature may be enabled through the driver providing a particular "DAS decrease" or "DAS revert" input, which is not possible or easy to perform by a rapid or simple input, such as the momentary press of a button. It may be possible, for example, by the driver providing an input which is indicative of a deliberate input, such as a long press on a button or by at least two button presses, or by selecting an option from a menu which must first be displayed by the driver and the option subsequently selected, possibly with a confirmatory further input being made, to help ensure the DAS functionality is not reduced unintentionally.
In some examples, the driver attention threshold is a dynamic threshold which varies dependent on the behaviour of the vehicle. The driver attention threshold may be dependent on whether the vehicle is performing a transfer of control event in some examples.
A 'transfer of control request" or "transition demand" may be considered to be a request that the vehicle makes to the driver to take full control of the driving task and may be called a "transfer of control event", i.e., the driver needs to take control of pedals and the steering of the vehicle. When operating a transfer of control request, for example transitioning from autonomous to manual driving, and when the driver is in an inattentive state, the control system 100 may be triggered to provide a high DAS 200 sensitivity level at least until determining that the driver has full control of the vehicle or until the vehicle stops.
The driver attention threshold may be dependent on whether the vehicle is performing a minimum risk manoeuvre in some examples. A "minimum risk manoeuvre" may be considered to be a procedure aimed at minirnisThg risks in traffic and aimed to stop the vehicle in a state of minimum risk condition. This may be automatically performed by the system after a transition demand without driver response. For example, when transitioning from autonomous driving control to manual driving control, or when undergoing a change in the level of autonomous driving control. During a minimum risk manoeuvre, the driver attention threshold may be changed, e.g. increased, so that the driver is for example, less fatigued, more attentive or responsive and more able to carry out the driving task, otherwise the control system 100 may be triggered to provide additional DAS 200 functionality. Advantageously, the DAS 200 can automatically provide increased driving assistance in a particular way to compensate for the way in which the vehicle is currently operating. When operating to transfer a control event, for example transitioning from autonomous to manual driving, a high DAS 200 activity level may be appropriate at least until determination that the driver has full control of the vehicle.
Figure 4 illustrates an example driver attention level input signal 310 which indicates a determined category of driver attention 312, 314, 316. The categories of driver attention 312, 314, 316 may comprise, for example, one or more of: driver drowsiness 312; driver distraction 314; and driver unresponsiveness 316. For example, driver drowsiness 312 may be determined due to detection of the driver's eyelids being closed, the driver's eyelids being closing and opening more often than a threshold number of eyelid closures e.g. a number of blinks per minute, the driver's eyelids being closed for longer than a predetermined time before opening (e.g. longer than 1 second, 3 seconds, or another time period), the driver's head position being tilted forwards or backwards indicative of drowsiness, the driver's eye gaze being located downwards, at least for a threshold period, any or all of which may be indicative of sleep, microsleep (i.e. sleep for a duration over the order of seconds e.g. 15 seconds or less) or fatigue. For example, driver distraction 314 may be determined due to detection of the driver's eye gaze direction not being sufficiently directed to the road ahead; the driver's eye gaze direction not being sufficiently directed to a region corresponding to a manoeuvre being performed, such as in the rear view mirror when reversing; detection of the driver's eye gaze being directed to a point of distraction such as an infotainment screen for a specified amount of time (e.g. more than 4 seconds) or mobile phone use detection, or detection of the noise level within the cabin being above a threshold noise volume, for example due to high music output volume or children or other occupants making a high volume of noise which may be distracting. For example, driver unresponsiveness 316 may be determined due to detection of the driver turning the steering wheel later than a predetermined response time; or the driver's manoeuvring, braking, or accelerating to change the vehicle movement being faster or slower than a predetermined movement change time; or the driver not responding to distraction or fatigue alerts. Driver unresponsiveness 316 may be determined if an alert or indicator is output and the driver does not respond to it after a predetermined time has passed. For example, if a distraction alert is provided and the driver is determined to remain in a distraction state and continues to drive without looking back to the road, this may be considered to indicate driver unresponsiveness.
The control system 100 may be configured to, in dependence on the determined category of driver attention 312, 314, 316, determine a type of driver assistance to be provided by the DAS 200 to provide the increase in automatic driver assistance functionality; and output the DAS control increase signal (306a-d) to cause the increase in automatic driver assistance functionality according to the determined type of driver assistance to be provided. This is illustrated as the driver attention level input signal 310 providing different type of DAS 200 functionality. In the example shown, driver attention of the driver drowsiness 312 type leads to a first type of DAS control increase signal 306a, driver attention of the driver distraction 314 type leads to a second type of DAS control increase signal 306b, driver attention of the driver unresponsiveness 316 type leads to a third type of DAS control increase signal 306c, and a combination of driver distraction 314 type and driver unresponsiveness 316 type leads to a fourth type of DAS control increase signal 306d. An illustrative example is shown in Figure 4, but other combinations and options may be implemented. Advantageously, in some examples there may be a tiered approach to controlling the DAS in response to a determined combination of driver attention states. For example, there may be a first level of increase in the control provided by the DAS via a first DAS control increase signal in response to a specific driver state indicated by the driver state input signal 310 being determined as a first less appropriate state; and a second level of increase in the control provided by the DAS via a second DAS control increase signal in response to the driver state indicated by the input signal 310 being determined as a second less appropriate state, a worse state than the first threshold. For example, on determining that a driver is distracted for a first period of time (e.g., 5 seconds), an indicator may be provided by the DAS to play an audio alert to attract the driver's attention to make them realise they are distracted and to focus on driving. On later determining that a driver is still distracted (e.g., for 15 seconds in total), the indicator may still be provided by the DAS alongside automatic "stay in lane" vehicle control provided by the DAS to try and get the driver to realise they are distracted, as well as partially controlling the steering of the driver to stay in lane.
In some examples, the response provided by the DAS 200 system may be to provide a type of DAS 200 increased functionality during a minimum risk manoeuvre. This action may be considered to be a final escalation of control provided by the DAS in response to low driver attention and make take place, for example, if the driver does not respond to warning alerts of their lack of attention, or if the driver is requested to take an action such as facing the road ahead or place their hands on the steering wheel and the requested action is not detected as taking place.
Figure 5 illustrates that the DAS control increase signal 306 may comprise, for instance, one or more different assistive functions 322, 324, 326, 328, 330. For example, the increased DAS 200 functionality may comprise lane assistance 322 configured to control the vehicle to be located within a driving lane; forward collision warning, and/or autonomous emergency braking provision 324 indicative of a risk and a possible mitigation of a potential forward collision with another road user; speed limit warning provision 326 indicative of a road speed limit at the location of the vehicle; new speed limit notification provision 328 indicative of a road speed limit change ahead of the vehicle; and blind spot monitoring provision 330 indicative of the presence of an object in a blind spot on any of the vehicle sides. Figure 5 shows an illustrative example, but other options of increased DAS 200 functionality may be implemented. Advantageously, the DAS 200 can automatically provide increased driving assistance in one or more different ways to most appropriately compensate for a less appropriate driver attention state. For example, by activating specific assistive functions in an increasing sensitivity level to provide earlier assistance.
Different categories of driver attention 312, 314, 316 may be responded to in different ways by the DAS. For example, if the driver is determined to be drowsy 312 then automatic lane assistance 322 with a specific feedback modality combination (e.g., audio, visual or haptics) may be provided to compensate for the drowsy driver being more likely to drift out of lane. For example, if the driver is determined to be distracted 314 then forward collision warning provision 324 may be provided earlier in the alert process and/or autonomous braking may intervene earlier when an object is detected ahead of the vehicle, to compensate for the distracted driver being more likely to not be observing the road ahead. Other examples include providing additional indicators or alerts to the driver to indicate the operation or increase in operation of a type of assistance provided by the DAS. Thus, the DAS 200 can be controlled to automatically provide increased driving assistance in a particular way to compensate for the way in which the driver is determined to be inattentive.
In some examples, the DAS 200 may be configured to operate in a plurality of driver assistance modes, wherein each of the plurality of modes provides a different level of automatic driver assistance functionality. Each driver assistance mode may provide one or more DAS functionalities set to a particular sensitivity level of operation together or as a group. In some examples, the control system 100 may be configured to output the DAS control increase signal 306 to cause the DAS 200 to operate in a high driver assistance mode to thereby cause the increase in automatic driver assistance functionality. Advantageously, there may be a discrete number of preprogramed driver assistance modes of operation of the DAS, and increasing the level of control provided by the DAS 200 means a high level of assistive control is provided. Previously, the level of control provided by the DAS 200 may have been in a lower mode of control (e.g. a low mode or a custom mode providing less assistive control than the high mode). Using a predetermined set of driver assistance control modes means the driver may more easily understand how the vehicle is being automatically controlled.
Moving the DAS control mode to a "high" (or higher mode) means there is a predetermined set of control functionality which is activated as a group in response to the driver attention level falling below the driver attention threshold. The use of driver assistance modes may be computationally more efficient than computing and activating a series of separate DAS 200 functionalities to particular levels of activity. In other examples the DAS may be moved to operate in another mode, such as a low mode or custom mode (offering less DAS functionality than the high mode); or the DAS may stay in a 'temporary override mode' where the current driver assistance mode is configured to provide specific driver assistance functionalities and sensitivity levels without changing modes; and/or moved to an emergency driver assistance mode (offering more DAS functionality than the high mode) in dependence on a more severe determined level of driver attentiveness.
The "high" DAS control mode may, in an example, be for the DAS system to automatically provide: a) forward collision alert and autonomous emergency braking are switched on and in an "early" sensitivity level (i.e. the forward collision alert is provided at an earlier time ahead of reaching an obstacle or determined point in the road which is longer in time than a lower sensitivity level whereby the alert is provided later; b) front cross traffic support is switched on (that is, the forward collision alert/autonomous emergency braking is switched on and set in the early sensitivity level in response to detection of traffic crossing ahead of the vehicle); c) lane departure warning (i.e. detection of the vehicle moving in a way indicative of a likelihood of the vehicle leaving the road lane) is turned on; d) steering assist is turned on (where the responsiveness of the steering is increased to enable easier driver steering of the vehicle); and e) emergency lane keep assist (whereby the vehicle is automatically controlled by the DAS to remain in the road lane when moving to the road edge or when moving to a lane with oncoming vehicles) turned on.
In other examples a different combination of at least some of these DAS systems, possibly in combination with one or more other DAS systems or settings of these or other systems, may be provided. Other such DAS systems may comprise a) blind spot monitoring being turned on (e.g. enabling detection of the presence of a potential obstacle in the blind spot on the vehicle sides); b) low speed emergency braking turned on; and c) rear cross traffic support (similar to front cross traffic support noted above but to the rear of the vehicle) enabled to provide an alert to the driver and corresponding braking assist turned on.
Figure 6 shows an example driver attention level determination module 400 and control system 100. The driver attention level determination module 400 may be part of a larger driver state sensing system 410. The driver attention level determination module 400 as shown may be configured to receive driver attention state input 402 indicative of the attention state of the driver. The driver attention state input may for example comprise an image of the drivers eyes, head, face, hands, arms or upper body, or sensor input indicative of the users hand position and applied pressure or rotation of the steering wheel or gearstick, for example. That is, the driver attention state input 402 may comprise driver facial input obtained from an image capture device, the driver facial input indicative of one or more of: driver facial expression, driver eye gaze direction, driver eyelid position, driver head inclination/tilt or eyelid closure duration. The driver attention state input 402 may also comprise steering wheel contact input obtained from a steering wheel sensor, the steering wheel contact input indicative of the contact or rotation of a driver's hand with the steering wheel of the vehicle.
The driver attention level determination module 400 may be configured to determine 404 the driver attention level input signal 306 in dependence on the driver attention state. For example, input 402 showing the driver having closed eyes may be determined to indicate that the driver is drowsy. The driver attention level determination module 400 may then be configured to provide 406 the driver attention level input signal 306 to the control system 100.
Advantageously, the driver attention level determination module 400 can use input from an image capture device such as a steering wheel mounted driver facing camera or cameras, or a pressure or touch sensor on the steering wheel, for example, and use the input from one or more such devices to determine a driver attention level.
Figure 7 illustrates a method 700 according to an embodiment of the invention. The method 700 is a method for controlling a DAS of a vehicle 10, such as the vehicle 10 illustrated in Figure 1. The method 700 may be performed by the control system 100 illustrated in Figure 2. In particular, the memory 130 may comprise computer-readable instructions which, when executed by the processor 120, perform the method 700 according to an embodiment of the invention. The method 700 comprises obtaining 702 a driver attention level input signal, the driver attention level input signal indicative of a determined level of driver attention to controlling operation of the vehicle; in dependence on the determined level of driver attention, determining 704 whether the level of driver attention is below a driver attention threshold; and in response to the level of driver attention being determined to be below the driver attention threshold, outputting 706 a DAS control increase signal, the DAS control increase signal to cause an increase in automatic driver assistance functionality to be provided by the DAS. Advantageously, there is a way to use control the DAS on board the vehicle to compensate for driver attention which does not reach the acceptable threshold for attentiveness without increased DAS activity. Advantageously, the method may be implemented as computer code, such as a computer on board the vehicle, and operate with existing technology such as driver attention detection elements and DAS elements.
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.