Vehicle control device, vehicle control method, and computer program for vehicle control

Abstract

To provide a vehicle control device capable of preventing a driver from ignoring a request for hand-on operation.SOLUTION: A vehicle control device comprises: a holding request section 32 which notifies a driver of a request to hold a steering wheel through a notification device 5 when a predetermined warning condition is met while operation control of a vehicle 10 is executed without the driver holding the steering wheel, and alerts the driver that the steering wheel is not being held through the notification device 5; a holding determination section 33 which determines whether or not the driver has held the steering wheel based on an in-vehicle sensor signal from in-vehicle sensors (3 and 4) detecting behavior of the driver; and a warning control section 34 which continues to warn the driver until the driver is determined to have held the steering even though the predetermined warning condition is no longer met after being notified of the request to hold the steering wheel.SELECTED DRAWING: Figure 3

Description

Technical Field

[0004] ,

[0001] The present invention relates to a vehicle control device, a vehicle control method, and a computer program for vehicle control.

Background Art

[0002] Depending on the level of autonomous driving control applied to a vehicle, the driver may be allowed to take their hands off the steering wheel during the vehicle's autonomous driving control. When such a level of autonomous driving control is applied to a vehicle, a technique has been proposed to request the driver to hold the steering wheel according to the situation (see Patent Document 1).

[0003] When the driving support device disclosed in Patent Document 1 determines that the driver is in an inappropriate state for vehicle surrounding monitoring, it warns the driver via a notification device and notifies the driver of a request to grip the steering wheel via the notification device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In some cases, after a request to hold the steering wheel (hereinafter sometimes referred to as a hands - on request or a hold request) is made, the factor that led to the notification of the hands - on request may be eliminated before the driver holds the steering wheel. In such a case, if the vehicle control device cancels the hands - on request and解除 the hands - off warning even when the driver does not hold the steering wheel, the driver may learn that the hands - off warning is解除 without holding the steering wheel and may stop following the hands - on request.

[0006] It should be noted that there seems to be an incorrect character "解除" in the original Japanese text which is translated as "解除" in the above translation. It might be a misspelling or an incorrect expression. It should be checked and corrected in the original content for a more accurate translation.Therefore, the present invention aims to provide a vehicle control device that can prevent the driver from ignoring hands-on requests. [Means for solving the problem]

[0007] According to one embodiment, a vehicle control device is provided. This vehicle control device includes: a determination unit that determines whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions when the vehicle's driving control is being performed without the driver holding the steering wheel; a hold request unit that, when the predetermined warning conditions are met, notifies the driver via a notification device of a hold request requesting the driver to hold the steering wheel, and also notifies the driver via the notification device of a warning that the driver is not holding the steering wheel; a hold determination unit that determines whether the driver has held the steering wheel according to in-vehicle sensor signals from in-vehicle sensors that detect the driver's actions; and a warning control unit that, after a hold request has been notified, continues to issue a warning until it is determined that the driver has held the steering wheel, even if the predetermined warning conditions are no longer met.

[0008] In this vehicle control device, the hold request unit increases the intensity of the warning as the elapsed time since the hold request was notified increases, and the warning control unit preferably stops the warning even if the driver is not holding the steering wheel if the predetermined warning conditions are no longer met while the warning intensity is at a first intensity, while continuing the warning even if the predetermined warning conditions are no longer met while the warning intensity is at a second intensity which is stronger than the first intensity, until it is determined that the driver is holding the steering wheel.

[0009] Furthermore, it is preferable that this vehicle control device further includes a vehicle control unit that controls the vehicle to stop if the driver does not maintain steering within a predetermined grace period after the warning intensity is changed to a second intensity.

[0010] Another embodiment provides a vehicle control method. This vehicle control method includes determining whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions when the vehicle's driving control is being performed without the driver holding the steering wheel, notifying the driver via a notification device of a hold request requiring the driver to hold the steering wheel if the predetermined warning conditions are met, notifying the driver via the notification device of a warning that the driver is not holding the steering wheel, determining whether the driver has held the steering wheel based on in-vehicle sensor signals from in-vehicle sensors that detect the driver's actions, and continuing the warning until it is determined that the driver has held the steering wheel, even if the predetermined warning conditions are no longer met after the hold request has been notified.

[0011] In yet another embodiment, a computer program for vehicle control is provided. The computer program for vehicle control includes instructions to cause a processor installed in the vehicle to perform the following actions when the vehicle is being controlled without the driver holding the steering wheel: determine whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions; if the predetermined warning conditions are met, notify the driver via a notification device of a hold request requesting the driver to hold the steering wheel; notify the driver via the notification device of a warning that the driver is not holding the steering wheel; determine whether the driver has held the steering wheel based on in-vehicle sensor signals from in-vehicle sensors that detect the driver's actions; and continue the warning even after the hold request has been notified, until it is determined that the driver has held the steering wheel. [Effects of the Invention]

[0012] The vehicle control device described herein has the effect of preventing the driver from ignoring hands-on requests. [Brief explanation of the drawing]

[0013] [Figure 1]This is a schematic diagram of the vehicle control system in which the vehicle control device is implemented. [Figure 2] This is a hardware configuration diagram of an electronic control unit. [Figure 3] This is a functional block diagram of the processor in an electronic control unit related to vehicle control processing. [Figure 4] Figures (a) to (c) illustrate the transitions in the hands-free warning notification process. [Figure 5] This is an operation flowchart of the vehicle control process. [Modes for carrying out the invention]

[0014] The following describes the vehicle control device, the vehicle control method executed on the vehicle control device, and the computer program for vehicle control, with reference to the diagram. After notifying the driver of a hands-on request, the vehicle control device continues to issue a warning (hereinafter referred to as a hands-off warning) that the driver is not holding the steering wheel, even after the cause of the hands-on request has been resolved, until the driver actually holds the steering wheel.

[0015] Figure 1 is a schematic diagram of a vehicle control system on which a vehicle control device is implemented. Figure 2 is a hardware diagram of an electronic control device, which is one embodiment of the vehicle control device. In this embodiment, the vehicle control system 1, which is mounted on and controls the vehicle 10, includes a camera 2, a driver monitor camera 3, a touch sensor 4, a notification device 5, and an electronic control unit (ECU) 6, which is an example of a vehicle control device. The vehicle control system 1 may further include a distance measuring sensor (not shown) such as LiDAR or radar for measuring the distance to objects in the vicinity of the vehicle 10. The vehicle control system 1 may also further include a satellite positioning device (not shown) such as a GPS receiver.

[0016] The camera 2 is an example of an external vehicle sensor, and is mounted, for example, inside the passenger compartment of the vehicle 10 so as to face the front of the vehicle 10. The camera 2 captures a predetermined area around the vehicle 10 at each predetermined imaging cycle to generate an image in which the predetermined area is shown, and outputs the generated image to the ECU 6.

[0017] The driver monitoring camera 3 is an example of an in-vehicle sensor that detects the driver's behavior, and is mounted, for example, on the instrument panel or in the vicinity thereof facing the driver so that the head of the driver sitting on the driver's seat of the vehicle 10 is included in the imaging target area. Then, the driver monitoring camera 3 captures the driver at each predetermined imaging cycle to generate an image in which the driver is shown (hereinafter referred to as a driver image), and outputs the generated driver image to the ECU 6. The driver image is an example of an in-vehicle sensor signal.

[0018] The touch sensor 4 is another example of an in-vehicle sensor, is attached to the steering wheel, and outputs a detection signal indicating that the driver has held the steering wheel to the ECU 6 when detecting that the driver has held the steering wheel. The detection signal is another example of an in-vehicle sensor signal.

[0019] The notification device 5 is provided inside the passenger compartment of the vehicle 10, and is a device that gives a predetermined notification to the driver by light, voice, vibration, character display, or image display. For this purpose, the notification device 5 has, for example, at least one of a speaker, a light source, a vibrator, or a display device. Then, when the notification device 5 receives a notification signal representing a predetermined warning such as a hands-on request to the driver from the ECU 6, it notifies the driver of the warning by voice from the speaker, emission or blinking of the light source, vibration of the vibrator, or display of a message on the display device. Note that the notification may be given by the notification device 5 via each of two or more types of devices.

[0020] The ECU 6 controls the automatic driving of the vehicle 10 or assists the driver in driving the vehicle 10. Further, when the ECU 6 is executing the automatic driving control of the vehicle 10 while the driver is not holding the steering wheel, if a predetermined warning condition is satisfied, the ECU 6 notifies the driver of a hands-on request via the notification device 5.

[0021] As shown in FIG. 2, the ECU 6 includes a communication interface 21, a memory 22, and a processor 23. The communication interface 21, the memory 22, and the processor 23 may each be configured as separate circuits, or may be integrally configured as one integrated circuit.

[0022] The communication interface 21 has an interface circuit for connecting the ECU 6 to other devices. The communication interface 21 transmits images, driver images, detection signals, etc. received from the camera 2, the driver monitoring camera 3, and the touch sensor 4 to the processor 23. Further, the communication interface 21 outputs the notification signal received from the processor 23 to the notification device 5.

[0023] The memory 22 is an example of a storage unit and has, for example, a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in the vehicle control process executed by the processor 23. Further, the memory 22 temporarily stores various data generated during the vehicle control process.

[0024] The processor 23 includes one or more CPUs (Central Processing Units) and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logical arithmetic unit, a numerical arithmetic unit, or a graphic processing unit. The processor 23 executes vehicle control processing for the vehicle 10 at a predetermined cycle.

[0025] Figure 3 is a functional block diagram of the processor 23 related to vehicle control processing. The processor 23 includes a determination unit 31, a hold request unit 32, a hold determination unit 33, a warning control unit 34, and a vehicle control unit 35. Each of these parts of the processor 23 is, for example, a functional module realized by a computer program running on the processor 23. Alternatively, each of these parts may be a dedicated arithmetic circuit provided on the processor 23.

[0026] The determination unit 31 determines whether predetermined warning conditions are met when the vehicle 10 is being controlled without the driver holding the steering wheel, and whether it would be inappropriate for the ECU 6 to continue controlling the vehicle 10 without the driver holding the steering wheel. The driver's holding of the steering wheel is determined by the holding determination unit 33, which will be described later.

[0027] For example, the determination unit 31 determines whether the conditions surrounding the vehicle 10 meet predetermined warning conditions. As an example, the determination unit 31 determines that predetermined warning conditions are met when the distance between the vehicle 10 and the lane markings that demarcate the vehicle's lane while the vehicle 10 is traveling falls below a predetermined distance.

[0028] The determination unit 31 inputs the image obtained by the camera 2 into the classifier to detect the left and right lane markings that demarcate the vehicle's own lane as shown in the image. The determination unit 31 then estimates the position of the lane markings corresponding to the reference position on the image, relative to the camera 2, based on the reference position of the pixels representing the left and right lane markings at a position close to the bottom edge of the image, and parameters such as the focal length, shooting direction, and installation height of the camera 2. The determination unit 31 then determines the distance from the vehicle 10 to the left and right lane markings based on the estimation result and the mounting position of the camera 2.

[0029] The determination unit 31 can detect lane markings by inputting the image into a classifier that has been pre-trained to detect lane markings from the image. The determination unit 31 can use a deep neural network (DNN) with a convolutional neural network (CNN) architecture, such as a Single Shot MultiBox Detector, as such a classifier. Alternatively, the determination unit 31 may use a classifier based on other machine learning methods, such as an AdaBoost classifier. Such a classifier is pre-trained using a large number of training images showing lane markings according to a predetermined learning method such as backpropagation, so as to detect the lane markings to be detected from the image.

[0030] Furthermore, the determination unit 31 may determine that a warning condition is met when the distance between the vehicle 10 and surrounding vehicles traveling around the vehicle 10 falls below a predetermined distance. In this case, the determination unit 31 detects surrounding vehicles by inputting the image into the classifier and estimates the distance between the vehicle 10 and the surrounding vehicles based on the position of the lower edge of the area where the surrounding vehicles are represented in the image and the parameters of the camera 2. Alternatively, if the vehicle 10 is equipped with a distance measuring sensor (not shown), the determination unit 31 may estimate the distance measured by the distance measuring sensor as the distance between the vehicle 10 and the surrounding vehicles, with respect to the direction corresponding to the center of gravity of the area where the surrounding vehicles are represented.

[0031] Furthermore, the determination unit 31 may determine whether the driver's condition meets predetermined warning conditions. For example, the determination unit 31 may determine that a warning condition is met if the driver's face is facing in a direction different from the direction of travel of the vehicle 10.

[0032] The determination unit 31 inputs the driver image into a classifier that has been pre-trained to detect the driver's face from the image, thereby detecting the region in the driver image where the driver's face is visible (hereinafter referred to as the face region), and also detecting multiple feature points of the driver's face, such as the outer corners of the eyes, inner corners of the eyes, tip of the nose, and corners of the mouth. In this process, the determination unit 31 inputs the driver image into a classifier that has been pre-trained to detect the face region and feature points of the face represented in the image, thereby detecting the face region and feature points of the face. As such a classifier, the determination unit 31 can use, for example, a DNN with a CNN-type architecture, a support vector machine, or an AdaBoost classifier. The determination unit 31 may also detect the face region and feature points of the face from the driver image according to other methods for detecting face regions and feature points of the face, such as template matching.

[0033] The determination unit 31 fits the individual feature points of the detected face to a 3D face model representing the 3D shape of the face. The determination unit 31 then detects the orientation of the face in the 3D face model that best fits each feature point to the 3D face model as the orientation of the driver's face. Alternatively, the determination unit 31 may detect the orientation of the driver's face based on the driver image using other methods for determining the orientation of the face represented in the image.

[0034] The determination unit 31 determines that the driver is facing a direction different from the direction of travel of the vehicle 10 if the detected orientation of the driver's face falls outside a predetermined allowable range centered on the direction of travel of the vehicle 10. The determination unit 31 may also determine that the driver is facing a direction different from the direction of travel of the vehicle 10 even if it cannot detect a face region from the driver image. The determination unit 31 only needs to detect the orientation of the driver's face as described above each time it acquires a driver image. The determination unit 31 then determines that the warning condition has been met if the duration for which the driver is facing a direction different from the direction of travel of the vehicle 10 exceeds a predetermined time threshold.

[0035] Furthermore, the determination unit 31 may determine the driver's alertness level based on a plurality of driver images obtained in a time series, and if the alertness level is below a predetermined threshold, it may determine that the warning condition is met. In this case, the determination unit 31 can determine the driver's alertness level according to a known method for determining the alertness level from a plurality of driver images obtained in a time series.

[0036] The determination unit 31 notifies the retention request unit 32 and the warning control unit 34 of the determination result of whether or not a predetermined warning condition is met.

[0037] When the holding request unit 32 receives a determination result from the determination unit 31 indicating that predetermined warning conditions have been met, it notifies the driver of a hands-on request via the notification device 5. The holding request unit 32 then notifies the warning control unit 34 and the vehicle control unit 35 that it has started notifying the hands-on request. Furthermore, simultaneously with the start of the hands-on request notification, or after a predetermined time has elapsed since the start of the notification, the holding request unit 32 notifies the driver of a hands-off warning via the notification device 5.

[0038] Furthermore, the holding request unit 32 increases the intensity of the hands-off warning as the elapsed time since the start of the hands-off warning notification increases. For example, the holding request unit 32 notifies the hands-off warning at a first intensity until the elapsed time reaches a predetermined switching time, and then notifies the hands-off warning at a second intensity that is stronger than the first intensity after the elapsed time reaches the predetermined switching time. Alternatively, the holding request unit 32 may switch the intensity of the warning in three or more stages depending on the elapsed time since the start of the hands-off warning notification.

[0039] The hold request unit 32 continues to notify the hands-off warning until it receives a stop instruction from the warning control unit 34 to stop notifying the hands-off warning, and then stops notifying the hands-off warning once it receives the stop instruction. In addition, after notifying the hands-on request, the hold request unit 32 continues to notify the hands-on request until it receives a release instruction, and then stops notifying the hands-on request once it receives the release instruction. Furthermore, if a stop instruction is not notified even after a predetermined grace period has passed since the intensity of the hands-off warning has been changed to the second intensity, the hold request unit 32 notifies the driver via the notification device 5 of an emergency stop warning to bring the vehicle 10 to an emergency stop.

[0040] The hold request unit 32 increases the volume of the warning sound from the speaker of the notification device 5, for example, as the intensity of the hands-off warning increases. Alternatively, the hold request unit 32 increases the brightness of the warning display from the display device or light source of the notification device 5 as the intensity of the hands-off warning increases. Alternatively, the hold request unit 32 may shorten the flashing interval of the warning display from the display device or light source of the notification device 5 as the intensity of the hands-off warning increases. Furthermore, the hold request unit 32 may increase the vibration of the vibrator of the notification device 5 as the intensity of the hands-off warning increases. Furthermore, if the notification device 5 has multiple devices, the hold request unit 32 may increase the number of devices that issue the warning as the intensity of the hands-off warning increases.

[0041] The holding determination unit 33 determines whether the driver is holding the steering wheel. For example, when it receives a detection signal from the touch sensor 4, the holding determination unit 33 determines that the driver is holding the steering wheel. Alternatively, the holding determination unit 33 may determine whether the driver is holding the steering wheel based on the driver image. In this case, the holding determination unit 33 detects the driver's hands and the steering wheel by inputting the driver image into a classifier that has been pre-trained to detect the driver's hands and the steering wheel from the driver image. The holding determination unit 33 then determines that the driver is holding the steering wheel if the detected position of the driver's hands overlaps with the detected position of the steering wheel. The holding determination unit 33 can use the same classifier as the determination unit 31 used for detecting the face region as the classifier for detecting the driver's hands and the steering wheel.

[0042] The holding determination unit 33 may determine that the driver is holding the steering wheel if it continuously receives a detection signal from the touch sensor 4 for a predetermined period of time or longer. Alternatively, the holding determination unit 33 may determine that the driver is holding the steering wheel if, for each of the multiple driver images obtained within the most recent predetermined period, the detected position of the driver's hand overlaps with the detected position of the steering wheel.

[0043] When the holding determination unit 33 determines that the driver is holding the steering wheel, it notifies the warning control unit 34 and the vehicle control unit 35 of the determination result.

[0044] The warning control unit 34 controls whether or not to continue notifying the hands-off warning. Specifically, when the warning control unit 34 receives a determination result from the holding determination unit 33 that the driver has held the steering wheel, it notifies the holding request unit 32 of a stop instruction and a release instruction. As a result, the notifications for the hands-off warning and the hands-on request are stopped. Furthermore, after the hands-on request has been notified, when the warning control unit 34 receives a determination result from the determination unit 31 that the warning conditions are no longer met, it notifies the holding request unit 32 of a release instruction.

[0045] Furthermore, when the intensity of the hands-off warning is at the first intensity, if the warning control unit 34 is notified that the warning condition is no longer met, it notifies the hold request unit 32 of a stop command, even if it has not received a determination that the driver has held the steering wheel.

[0046] On the other hand, even if the determination unit 31 notifies that the warning condition is no longer met when the intensity of the hands-off warning is stronger than the first intensity (second intensity or higher), the warning control unit 34 will not notify the hold request unit 32 of a stop command until it receives a determination result from the hold determination unit 33 that the driver has held the steering wheel. The warning control unit 34 may also refrain from notifying a release command until it receives a determination result that the driver has held the steering wheel. Therefore, when the intensity of the hands-off warning is stronger than the second intensity, the notification of the hands-off warning will not stop until the driver holds the steering wheel. In this way, the system switches whether or not it is essential for the driver to hold the steering wheel in order to stop the warning, depending on the intensity of the warning, so the warning control unit 34 can prevent the driver from ignoring the hands-on request without compromising the driver's convenience.

[0047] The vehicle control unit 35 controls the vehicle 10 according to the level of automatic driving control applied to the vehicle 10. The level of automatic driving control applied to the vehicle 10 can be a level that allows hands-free driving, such as Level 2 as defined by the Society of Automotive Engineers (SAE). Furthermore, if the vehicle control unit 35 does not receive notification from the steering wheel holding determination unit 33 that the driver has held the steering wheel even after a predetermined grace period has elapsed since the intensity of the hands-free warning was changed to the second intensity, the vehicle control unit 35 activates the Emergency Driving Stop System (EDSS) function. That is, the vehicle control unit 35 controls the vehicle 10 to decelerate to a predetermined slow speed and then to a stop. To this end, the vehicle control unit 35 sets the accelerator opening or brake amount to achieve a preset deceleration. The vehicle control unit 35 then controls the power mechanism of the vehicle 10, such as the engine or motor, according to the set accelerator opening. In addition, the vehicle control unit 35 outputs a control signal to the brakes of the vehicle 10 according to the set brake amount. When the vehicle 10 comes to a stop, the vehicle control unit 35 controls various parts of the vehicle 10 to maintain the stopped state. That is, the vehicle control unit 35 controls the brakes so that the amount of braking is such that the vehicle 10 does not move. Furthermore, the vehicle control unit 35 may control the shift control mechanism so that the shift position becomes the parking position, or it may activate the parking brake.

[0048] In this way, if the driver does not maintain steering control even after a predetermined grace period has elapsed since the hands-off warning intensity was changed to the second intensity, the vehicle control unit 35 will bring the vehicle 10 to an emergency stop. This allows the processor 23 to teach the driver that ignoring the hands-on request is detrimental. Therefore, the processor 23 can more effectively prevent the driver from ignoring the hands-on request.

[0049] Furthermore, once the EDSS function is activated, the processor 23 may limit the level of autonomous driving control applicable to the vehicle 10 to a level that requires the driver to hold the steering wheel, until the ignition switch is turned off.

[0050] Figures 4(a) to 4(c) illustrate the transitions in the hands-off warning notification process. In Figures 4(a) to 4(c), the horizontal axis represents elapsed time. Furthermore, charts 401 to 404 represent the status of fulfillment of the warning conditions, the driver's state regarding steering wheel retention, the notification status of the hands-on request, and the notification status of the warning, respectively. In the example in Figure 4(a), the warning conditions remain met after the start of the hands-on request notification, and the driver continues not to hold the steering wheel. As shown in charts 401 and 403, at time t0, the warning conditions are met and the hands-on request notification begins. Subsequently, as shown in chart 404, the hands-off warning notification begins at the first intensity (weak warning). Then, at time t1, the intensity of the hands-off warning changes from the first intensity to the second intensity (strong warning). As shown in Chart 402, since the driver does not continue to hold the steering wheel, at time t2, when the grace period from time t1 has elapsed, the notification switches from a hands-off warning to an emergency stop warning, and then vehicle 10 is brought to an emergency stop.

[0051] In the example in Figure 4(b), the warning condition is resolved while the hands-off warning intensity is at the first intensity (weak warning). In this example as well, as shown in Charts 401 and 403, the hands-on request notification begins at time t0. Furthermore, as shown in Chart 404, the hands-off warning notification begins at the first intensity. Then, as shown in Chart 402, the driver continues to keep their hands off the steering wheel. However, in this example, as shown in Chart 401, the warning condition is resolved at time ta before the transition time has elapsed. As a result, the hands-on request and hands-off warning notifications stop after time ta.

[0052] In the example in Figure 4(c), the hands-off warning intensity is changed to the second intensity (strong warning) before the warning condition is resolved. In this example as well, as shown in Charts 401 and 403, the notification of the hands-on request begins at time t0. Also, as shown in Chart 404, the notification of the hands-off warning begins at the first intensity. Furthermore, at time t1, the intensity of the hands-off warning is changed from the first intensity to the second intensity. Subsequently, at time tb, the warning condition is resolved. However, after time t1, as shown in Charts 402 and 404, even if the warning condition is resolved, the notification of the hands-off warning continues as long as the driver does not hold the steering wheel. If the driver does not hold the steering wheel at time t2, the notified warning switches from a hands-off warning to an emergency stop warning, and then the vehicle 10 makes an emergency stop.

[0053] Figure 5 is an operation flowchart of the vehicle control process. The processor 23 should execute the vehicle control process according to the operation flowchart below.

[0054] The determination unit 31 determines whether or not the warning condition is met (step S101). If the warning condition is not met (step S101-No), the vehicle control unit 35 continues to control the vehicle 10 according to the level of automatic driving control applied to the vehicle 10. On the other hand, if the warning condition is met (step S101-Yes), the hold request unit 32 notifies the driver of a hands-on request via the notification device 5 (step S102). Furthermore, after a predetermined time has elapsed since the start of the hands-on request notification, the hold request unit 32 notifies the driver of a hands-off warning at a first intensity via the notification device 5 (step S103).

[0055] Subsequently, the holding determination unit 33 determines whether or not it has detected that the driver has held the steering wheel (step S104). If it is detected that the driver has held the steering wheel (step S104-Yes), the warning control unit 34 stops notifying the holding request unit 32 of the hands-off warning and hands-on request (step S105). Subsequently, the vehicle control unit 35 continues to control the vehicle 10 according to the level of automatic driving control applied to the vehicle 10.

[0056] On the other hand, if it is not detected that the driver has held the steering wheel (step S104-No), the hold request unit 32 determines whether the switching time has elapsed since the start of the hands-off warning notification (step S106). If the switching time has elapsed (step S106-Yes), the hold request unit 32 changes the intensity of the hands-off warning from the first intensity to the second intensity (step S107). Furthermore, the processor 23 determines whether the grace period has elapsed since the intensity of the hands-off warning was changed to the second intensity (step S108). If the grace period has not elapsed (step S108-No), the processor 23 repeats the processing from step S104 onwards.

[0057] If the grace period has elapsed (step S108-Yes), the hold request unit 32 notifies the driver of an emergency stop warning via the notification device 5 (step S109). Subsequently, the vehicle control unit 35 controls the vehicle 10 to bring it to a stop (step S110).

[0058] Furthermore, in step S106, if the switching time has not elapsed (step S106-No), the determination unit 31 determines whether the warning condition has been resolved (step S111). If the warning condition has been resolved (step S111-Yes), the processor 23 executes the process in step S105. On the other hand, if the warning condition has not been resolved (step S111-No), the processor 23 executes the processes from step S104 onwards.

[0059] As explained above, this vehicle control system can prevent the driver from ignoring hands-on requests.

[0060] In a modified version, the warning control unit 34 may count the number of times the hands-off warning is automatically canceled when the warning condition is no longer met while the intensity of the hands-off warning is at the first intensity, and the driver does not hold the steering wheel. When the number of automatic cancellations exceeds a certain level, the hold request unit 32 may set the intensity of the hands-off warning to the second intensity from the beginning. In this case, the hands-off warning notification will continue from immediately after the notification starts, unless the driver holds the steering wheel.

[0061] In a modified version, the hold request unit 32 may set the intensity of the hands-off warning to a constant level, regardless of the elapsed time since the start of the hands-off warning notification. In this case, after the hands-on request is notified, the warning control unit 34 may not notify an instruction to stop the hands-off warning even if the warning conditions for notifying the hands-on request are no longer met, unless it receives a determination result from the hold determination unit 33 that the driver has held the steering wheel. Therefore, in this case, similar to the case in the above embodiment where the intensity of the hands-off warning is the second intensity, the hands-off warning notification continues until the driver holds the steering wheel, even if the warning conditions are no longer met after the hands-on request is notified.

[0062] The computer program that realizes the functions of the processor 23 of the ECU 6 according to the above embodiment or modification may be provided in the form of being recorded on a computer-readable portable recording medium such as semiconductor memory, magnetic recording medium, or optical recording medium.

[0063] As described above, those skilled in the art can make various modifications within the scope of the present invention to suit the implemented form. [Explanation of symbols]

[0064] 1. Vehicle control system 10 vehicles 2 cameras 3. Driver Monitor Camera 4 Touch Sensors 5 Notification device 6. Electronic Control Unit (ECU) 21 Communication Interface 22 memory 23 processors 31 Judgment section 32 Hold request part 33 Holding judgment section 34 Warning Control Unit 35 Vehicle Control Unit

Claims

1. When the vehicle's driving control is being performed without the driver holding the steering wheel, a determination unit determines whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions, When the predetermined warning conditions are met, the Hold Request Unit notifies the driver via a notification device of a Hold Request request, instructing the driver to hold the steering wheel, and also notifies the driver via the notification device of a warning that the driver is not holding the steering wheel. A holding determination unit determines whether the driver is holding the steering wheel based on in-vehicle sensor signals from in-vehicle sensors that detect the driver's actions, A warning control unit that, after the aforementioned holding request has been notified, continues the warning until it is determined that the driver has held the steering wheel even if the predetermined warning conditions are no longer met, It has, The retention request unit increases the intensity of the warning as the elapsed time since the retention request was notified increases. The warning control unit stops the warning even if the driver is not holding the steering wheel if the predetermined warning conditions are no longer met while the warning intensity is at a first intensity, while continuing the warning even if the predetermined warning conditions are no longer met while the warning intensity is at a second intensity which is stronger than the first intensity, until it is determined that the driver is holding the steering wheel. Vehicle control system.

2. The vehicle control device according to claim 1, further comprising a vehicle control unit that controls the vehicle to stop if the driver does not maintain steering within a predetermined grace period after the intensity of the warning is changed to the second intensity.

3. When the vehicle's driving control is being performed without the driver holding the steering wheel, it is determined whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions. When the predetermined warning conditions are met, the driver is notified via the notification device of a hold request requiring them to hold the steering wheel, and a warning is also issued via the notification device if the driver is not holding the steering wheel. Whether or not the driver is holding the steering wheel is determined based on the in-vehicle sensor signals from the in-vehicle sensors that detect the driver's actions. After the aforementioned request to hold the steering wheel is notified, the warning continues until it is determined that the driver has held the steering wheel, even if the predetermined warning conditions are no longer met. This includes, The notification of the driver not holding the steering wheel via the notification device includes increasing the intensity of the warning as time elapses since the request to hold the steering wheel was notified. Continuing the warning until it is determined that the driver is holding the steering wheel, even if the predetermined warning conditions are no longer met, includes stopping the warning even if the driver is not holding the steering wheel, if the predetermined warning conditions are no longer met while the warning intensity is at a first intensity, and continuing the warning until it is determined that the driver is holding the steering wheel, even if the predetermined warning conditions are no longer met while the warning intensity is at a second intensity which is stronger than the first intensity. Vehicle control method.

4. When the vehicle's driving control is being performed without the driver holding the steering wheel, it is determined whether the conditions around the vehicle or the driver's condition meet predetermined warning conditions. When the predetermined warning conditions are met, the driver is notified via the notification device of a hold request requiring them to hold the steering wheel, and a warning is also issued via the notification device if the driver is not holding the steering wheel. Whether or not the driver is holding the steering wheel is determined based on the in-vehicle sensor signals from the in-vehicle sensors that detect the driver's actions. After the aforementioned request to hold the steering wheel is notified, the warning continues until it is determined that the driver has held the steering wheel, even if the predetermined warning conditions are no longer met. This includes instructions to cause the processor mounted on the vehicle to perform the following: The notification of the driver not holding the steering wheel via the notification device includes increasing the intensity of the warning as time elapses since the request to hold the steering wheel was notified. Continuing the warning until it is determined that the driver is holding the steering wheel, even if the predetermined warning conditions are no longer met, includes stopping the warning even if the driver is not holding the steering wheel, if the predetermined warning conditions are no longer met while the warning intensity is at a first intensity, and continuing the warning until it is determined that the driver is holding the steering wheel, even if the predetermined warning conditions are no longer met while the warning intensity is at a second intensity which is stronger than the first intensity. Computer programs for vehicle control.

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