JP2010215156A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control device capable of preventing a vehicle stopping on a slope from slipping down by gravity when a wakefulness level of a driver decreases. <P>SOLUTION: The vehicle control device controls so as to hold a braking force of the vehicle after brake operation is released. The vehicle control device includes a wakefulness level detecting means 11 for detecting the wakefulness level of the driver, and a set changing means 12 for changing starting condition or releasing condition of the control or targeted braking force when the wakefulness level detection means 11 detects the decrease in the wakefulness level of the driver. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control device that controls a braking force of a vehicle.

  2. Description of the Related Art Conventionally, as a vehicle control device that controls a braking force of a vehicle, a device that performs control (generally referred to as “hill hold control”) capable of holding the braking force of the vehicle after release of a brake operation is known ( For example, see Patent Documents 1 and 2). The vehicle control device starts hill hold control when the brake pedal is depressed more than a predetermined amount while the vehicle is stopped. As a result, the braking force is maintained even when the brake pedal is depressed gradually, so that it is possible to prevent the vehicle that is stopped on the slope from sliding down due to gravity.

  The vehicle control device described in Patent Document 1 includes a detection unit that detects a road surface gradient, and a road surface gradient in a direction in which the vehicle's own weight acts in the traveling direction (the road surface gradient is a downward gradient from the rear of the vehicle toward the front of the vehicle). In this case, the hill hold control is not performed because the driver expects the vehicle to travel along the gradient. Therefore, it is possible to suppress the driver from feeling uncomfortable.

  The vehicle control device described in Patent Literature 2 releases the hill hold control when the elapsed time after the release of the brake operation reaches a predetermined time or when the accelerator pedal is depressed. In addition, in the case of a manual transmission (MT) vehicle, the hill hold control is canceled even when the amount of depression of the clutch pedal becomes a predetermined amount or less in addition to the above conditions.

JP 2001-163199 A Japanese Patent Laid-Open No. 11-310119

  However, in the conventional vehicle control device, the driver's arousal level is not taken into consideration. When the driver's arousal level is lowered, the driver's thinking ability and exercise ability are lowered, and there is a possibility that the vehicle that is stopped on the hill is lowered by gravity.

  The present invention has been made in view of the above, and it is possible to prevent a vehicle that is stopped on a slope from falling down due to gravity when the driver's arousal level is low. The purpose is to provide.

In order to achieve the above object, the present invention provides a vehicle control device that performs control capable of maintaining a braking force of a vehicle after releasing a brake operation.
Wakefulness detection means for detecting the driver's wakefulness,
When the wakefulness detection means detects a decrease in the driver's wakefulness, the control is provided with a setting change means for changing the start condition or release condition of the control or the target braking force.

  ADVANTAGE OF THE INVENTION According to this invention, when the driver | operator's arousal level is falling, the vehicle control apparatus which can prevent the vehicle stopped on a slope from sliding down by gravity is obtained.

It is a block diagram which shows the vehicle-mounted system relevant to the control apparatus for vehicles of one Example of this invention. 2 is a diagram showing a hydraulic circuit of the brake device 20. FIG. It is a flowchart which shows an example of the process which ECU10 performs. FIG. 4 is a flowchart illustrating an example of a process executed by an ECU 10 following the process of FIG. 3.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing an in-vehicle system related to a vehicle control apparatus according to an embodiment of the present invention. The vehicle control device is configured around an electronic control unit 10 (hereinafter referred to as “ECU 10”) that controls the braking force of the vehicle. ECU10 is comprised as a microcomputer which consists of CPU, ROM, RAM, etc. which were mutually connected via the bus | bath which is not shown in figure. The CPU executes a program stored in the ROM or the like. Data generated during execution of the CPU is stored in a RAM or the like.

  The ECU 10 includes a brake device 20, various sensors 40, a driver monitor camera 50, a road surface gradient detection sensor 60, a distance sensor 70, a hazard lamp 82, a horn 84, and a communication device 86 via an in-vehicle network such as CAN or LIN. It is connected.

  FIG. 2 is a diagram illustrating a hydraulic circuit of the brake device 20. In FIG. 2, the arrow indicates the normal flow of the brake fluid when the brake pedal 22 is depressed by the driver. When the brake pedal 22 is depressed by the driver, the pedal force is converted into brake hydraulic pressure by the master cylinder 24. The master cylinder 24 is further connected to a wheel cylinder 28 of each wheel via a liquid passage 26 (only one wheel is shown).

  In the flow passage 26, a holding valve 32, a check valve 34, and a hydraulic pump 35 are provided. The holding valve 32 is an electromagnetic valve that is normally open and is closed when electric power is supplied to the internal electromagnetic coil. The check valve 34 is provided in parallel with the holding valve 32 and allows only a liquid flow from the master cylinder 24 to the wheel cylinder 28. The hydraulic pump 35 is provided on the downstream side of the holding valve 32 and the check valve 34 and is used to increase the pressure inside the wheel cylinder 28 (hereinafter referred to as “wheel cylinder pressure Ph”). Switching of the open / close state of the holding valve 32 and the on / off of the hydraulic pump 35 is controlled by the ECU 10 (mainly the braking force control unit 13).

  In normal times, when the brake pedal 22 is depressed by the driver, brake hydraulic pressure corresponding to the depression force is generated. The brake hydraulic pressure is supplied to the wheel cylinder 28 via the holding valve 32 and the check valve 34. The wheel cylinder 28 presses the friction pad 36 against the brake rotor 38 that rotates together with the wheel in accordance with the wheel cylinder pressure Ph. Thereby, braking force is expressed. When the depression of the brake pedal 22 is released, the brake fluid is collected from the wheel cylinder 28 to the master cylinder 24 via the holding valve 32, and the wheel cylinder pressure Ph is reduced. As a result, the friction pad 36 is separated from the brake rotor 38 and the braking force is released. Thus, during normal times, a braking force is generated according to the operation of the brake pedal 22.

  On the other hand, when the holding valve 32 is closed in a state where the brake pedal 22 is depressed (that is, when electric power is supplied to the electromagnetic coil inside the holding valve 32 under the control of the ECU 10), the wheel is turned on. The cylinder 28 and the master cylinder 24 are shut off. Therefore, even if the depression of the brake pedal 22 is released, the wheel cylinder pressure Ph is not reduced, so that the braking force is maintained. Therefore, it is possible to prevent the vehicle stopped on the slope from sliding down due to gravity.

  When the brake pedal 22 is further depressed while the braking force is maintained, the brake hydraulic pressure corresponding to the depression force is supplied to the wheel cylinder 28 via the check valve 34, so that the wheel cylinder pressure Ph is further increased. The Thus, the braking force can be maintained when the depression of the brake pedal 22 is released, and the braking force can be increased when the depression of the brake pedal 22 is performed.

  Further, when the hydraulic pump 35 is driven by the ECU 10 while the braking force is maintained, the wheel cylinder pressure Ph is further increased. As a result, when the depression of the brake pedal 22 is released, the braking force can be maintained and the braking force can be increased.

  Further, when the holding valve 32 is opened in a state where the braking force is held (that is, when the electrode supply to the electromagnetic coil inside the holding valve 32 is released under the control of the ECU 10), the brake fluid Is recovered from the wheel cylinder 28 to the master cylinder 24 via the holding valve 32, and the wheel cylinder pressure Ph is reduced. Thereby, holding | maintenance of braking force is cancelled | released.

  The various sensors 40 are sensors that acquire vehicle information. For example, the vehicle speed sensor 42 that detects the vehicle speed of the vehicle, the brake sensor 44 that detects the amount of depression of the brake pedal 22, and the amount of depression of an accelerator pedal (not shown). And a clutch sensor 48 for detecting the amount of depression of a clutch pedal (not shown). Various sensors 40 may have a known configuration. The vehicle information acquired by the various sensors 40 is supplied to the ECU 10 (mainly the braking force control unit 13) every predetermined time. If the vehicle subject to hill hold control is an automatic transmission (AT) vehicle, the clutch sensor 48 is naturally unnecessary.

  The driver monitor camera 50 is a camera that acquires driver information, and includes an infrared camera 52 that captures a driver's face image and an image processing device 54 that processes the face image. The image processing device 54 is configured by a microcomputer, and calculates the driver's closed eye duration by image processing. For example, the distance between the upper eyelid and the lower eyelid of the driver's eyes is measured by image processing, and the driver's eye duration time is calculated from the change in the distance. A decrease in the driver's arousal level can be detected using the calculated closed eye duration time and a map showing the relationship between the closed eye duration time and the arousal level stored in advance in a ROM or the like. The driver information acquired by the driver monitor camera 50 is supplied to the ECU 10 (mainly the arousal level detection unit 11) every predetermined time.

  The road surface gradient detection sensor 60 is a sensor that acquires road surface information around the vehicle, and is composed of, for example, a G sensor. The G sensor is a sensor that is mounted on a vehicle as a standard and detects acceleration in the longitudinal direction of the vehicle. When the vehicle stops on a slope, since the slope has a road surface gradient of angle θ, gravity acting on the vehicle is divided, and one of the component forces acts as a force for moving the vehicle along the road surface gradient. Therefore, by detecting the magnitude and direction of gravity component in the longitudinal direction of the vehicle (whether forward or backward), the road surface slope angle θ and direction (from the vehicle rear to the vehicle front It is possible to detect whether the slope is downhill). The road surface information acquired by the road surface gradient detection sensor 60 is supplied to the ECU 10 (mainly the braking force control unit 13) every predetermined time.

  In addition, although the road surface gradient detection sensor 60 of the present embodiment is configured by the G sensor, it may be configured by a navigation ECU (not shown). The navigation ECU recognizes the position of the vehicle based on a signal from a GPS satellite received via the GPS receiver and map data in the map database. The map data in the map database includes road information related to general roads and highways on which vehicles travel. The road information includes an angle θ and a direction of the road surface gradient. Therefore, the navigation ECU can detect the angle θ and the direction of the road gradient from the own vehicle position and the road information in the map database.

  The distance measuring sensor 70 is a sensor that acquires peripheral vehicle information such as a preceding vehicle and a succeeding vehicle. For example, the distance measuring sensor 70 is configured by a millimeter wave radar, a laser radar, an ultrasonic sensor, or the like, and transmits a radio wave or the like to a predetermined range (for example, a range within 100 m forward of the vehicle) in front of the vehicle or behind the vehicle. , The presence / absence of the preceding vehicle and the following vehicle, the distance between the preceding vehicle and the following vehicle, and the relative speed are detected. The surrounding vehicle information acquired by the distance measuring sensor 70 is supplied to the ECU 10 (mainly the braking force control unit 13) every predetermined time.

  A mode switch 88 is connected to the ECU 10. The mode switch 88 is provided in the passenger compartment and can be operated by the driver. The mode switch 88 is normally maintained in an off state, and is turned on by a driver's operation.

  Based on the output signal of the mode switch 88, the ECU 10 determines whether or not the driver needs brake assistance. That is, when the mode switch 88 is turned on, the ECU 10 starts a process for executing control (hereinafter referred to as “hill hold control”) that can maintain the braking force after the release of the brake operation.

  As shown in FIG. 1, the ECU 10 includes an arousal level detection unit (wake level detection unit) 11, a setting change unit (setting change unit) 12, a braking force control unit (braking force control unit) 13, and a warning notification unit (warning notification). Means) 14 and a communication control unit (communication control means) 15. ECU10 stores the program corresponding to each part 11-15 in ROM etc., makes CPU execute this program, and implement | achieves the function which each part 11-15 has. Hereinafter, functions of the respective units 11-15 will be described.

  The arousal level detection unit 11 has a function of detecting the driver's arousal level. The arousal level detection unit 11 inputs driver information from the driver monitor camera 50, for example, detects the driver's arousal level, sets the detection result (whether or not the awakening level is reduced), the setting change unit 12, and the warning notification unit 14 And a function of outputting to the communication control unit 15.

  The setting changing unit 12 has a function of changing the start condition or release condition of the hill hold control or the target braking force when the detection result of the arousal level detection unit 11 indicates a decrease in the driver's arousal level. The start condition or release condition before or after the change, or the target braking force is stored in advance in the ROM or the like, and is read out as necessary.

  The starting conditions are (1) the vehicle speed V is equal to or less than a predetermined value V0 (the predetermined value V0 is a value considering a measurement error of the vehicle speed V and may be substantially 0), and (2) the road surface gradient is If the slope is equal to or greater than the predetermined angle θ0, (3) the brake operation amount (depressed amount of the brake pedal 22) BV is equal to or greater than the first predetermined amount BV0, and (4) the host vehicle The vehicle-to-vehicle distance FL is within the first predetermined distance FL0, and (5) when the road surface gradient is an uphill gradient, the inter-vehicle distance BL between the host vehicle and the following vehicle is within the second predetermined distance BL0. Any one of the certain conditions may be used, or a condition obtained by combining any plural conditions with AND or OR.

  As the start condition, the start condition (1) and the start condition (3) are combined by AND, or the start condition (1), the start condition (3) and another start condition are combined by AND. Conditions are preferred. By combining the start condition (1) and the start condition (3) with AND, it is possible to reliably determine whether or not the vehicle is stopped.

  When a decrease in the driver's arousal level is detected, the predetermined angle θ0 is small, the first predetermined amount BV0 is small, the first predetermined distance FL0 is large, and the second predetermined distance BL0 is large. In the case of a condition in which a plurality of arbitrary conditions are combined by AND or OR, among the corresponding reference values (predetermined angle θ0, first predetermined amount BV0, first predetermined distance FL0, second predetermined distance BL0) It is sufficient that at least one of the reference values is changed.

  As described above, when a decrease in the driver's arousal level is detected, the start condition is generally changed when the driver's arousal level is decreased. Because. For example, when the driver's arousal level is low, the time from release of the brake operation to the accelerator operation is longer than usual, and the vehicle may slide down due to gravity even on a gentle road surface gradient. Set. In addition, when the driver's arousal level is low, the brake operation amount may be smaller than normal (the driver's pedaling force may be smaller than normal), so the first predetermined amount BV0 is set small. Furthermore, when the driver's arousal level is reduced, the time from the release of the brake operation to the accelerator operation is longer than usual, and the distance of sliding down becomes longer. Therefore, the first and second predetermined distances FL0 and BL0 are set as follows. Set larger. Accordingly, when the driver's arousal level is reduced, it is possible to prevent the vehicle that is stopped on the slope from sliding down due to gravity, and to prevent contact with a pedestrian or another vehicle.

  The release conditions are (1) the elapsed time T after release of the brake operation (after release of the operation of the brake pedal 22) is equal to or longer than the predetermined time T0, and (2) accelerator operation amount (depressed amount of the accelerator pedal). AV is equal to or greater than the second predetermined amount AV0, and (3) the clutch operation amount (the clutch pedal depression amount) CV is equal to or smaller than the third predetermined amount CV0. Alternatively, it may be a condition obtained by combining arbitrary plural conditions with AND or OR. When the vehicle subject to hill hold control is an automatic transmission (AT) vehicle, the release condition (3) is naturally not necessary.

  In the release condition (1), whether or not the brake operation is released is determined based on the brake operation amount BV. When the brake operation amount BV is equal to or less than the fourth predetermined amount BV1, the brake operation is released. It is determined that The elapsed time T is measured using a timer built in the ECU 10.

  When a decrease in the driver's arousal level is detected, the predetermined time T0 is set large, the second predetermined amount AV0 is set large, and the third predetermined amount CV0 is set small. In the case of a condition obtained by combining a plurality of arbitrary conditions with AND or OR, at least one of the corresponding reference values (predetermined time T0, second predetermined amount AV0, third predetermined amount CV0) is used. The value only needs to be changed.

  As described above, when a decrease in the driver's arousal level is detected, the cancellation condition is generally changed when the driver's arousal level is decreased. Because. For example, when the driver's arousal level is reduced, the time from the release of the brake operation to the accelerator operation may be longer than usual, so the predetermined time T0 is set to be large. In addition, when the driver's arousal level is low, the accelerator pedal depressing operation may become slow, so the second predetermined amount AV0 is set large. In addition, when the driver's arousal level is low, the stepping back operation of the clutch pedal may become slow, so the third predetermined amount CV0 is set small. Accordingly, when the driver's arousal level is reduced, it is possible to prevent the vehicle that is stopped on the slope from sliding down due to gravity, and to prevent contact with a pedestrian or another vehicle.

  The target braking force is set large when a decrease in the driver's arousal level is detected. When the driver's arousal level is low, the time from the release of the brake operation to the accelerator operation is longer than usual, and the braking force (wheel cylinder pressure Ph) to be held during that time may be released from the holding valve 32 or the like. Therefore, set a large target braking force. Accordingly, when the driver's arousal level is reduced, it is possible to prevent the vehicle that is stopped on the slope from sliding down due to gravity, and to prevent contact with a pedestrian or another vehicle.

  The setting changing unit 12 has a function to initialize the start condition or release condition of the hill hold control or the target braking force when the detection result of the arousal level detection unit 11 does not indicate a decrease in the driver's arousal level. Have.

  The braking force control unit 13 has a function of performing hill hold control based on the start condition and the release condition set after the detection of the driver's arousal level and the target braking force. The determination of whether the start condition and the release condition are satisfied is based on vehicle information supplied from various sensors 40, road surface information supplied from the road surface gradient detection sensor 60, and surrounding vehicle information supplied from the distance measuring sensor 70. To do.

  When the set start condition is satisfied, the braking force control unit 13 supplies power to the electromagnetic coil inside the holding valve 32 and closes the holding valve 32 to start hill hold control. When the target braking force is set large, in addition to closing the holding valve 32, the hydraulic pump 35 is driven (duty controlled) to obtain the target braking force (target wheel cylinder pressure). Based on this, the wheel cylinder pressure Ph is increased. Further, when the set release condition is satisfied during the hill hold control, the braking force control unit 13 releases the power supply to the electromagnetic coil inside the holding valve 32 and opens the holding valve 32. Then, release hill hold control.

  The warning notification unit 14 has a function of reporting a warning to the outside of the vehicle when the detection result of the wakefulness detection unit 11 indicates a decrease in the driver's wakefulness. The warning notification unit 14 notifies a warning to the outside of the vehicle via, for example, the hazard lamp 82 and the horn 84. By turning on the hazard lamp 82 and emitting an electronic sound from the horn 84, the driver and pedestrian of the vehicle ahead and the following vehicle can be alerted.

  If the detection result of the arousal level detection unit 11 indicates a decrease in the driver's arousal level, the communication control unit 15 issues an alarm to other vehicles (the preceding vehicle and the following vehicle) via the communication device 86. Send. The other vehicle that has received the warning from the communication device 86 outputs the warning through a display or a speaker (not shown) provided in the passenger compartment of the other vehicle. Thereby, it is possible to alert the driver of the preceding vehicle or the following vehicle.

  3 and 4 are flowcharts illustrating an example of processing executed by the ECU 10. For example, when the mode switch 88 is turned on, the ECU 10 executes the processing after S100 in FIG. 3 at predetermined time intervals.

  In S100 of FIG. 3, the arousal level detection unit 11 monitors the driver's arousal level. When the driver's arousal level is decreasing (S100, YES), the process proceeds to S102, and after the setting changing unit 12 changes the start and release conditions of the hill hold control and the target braking force, the process proceeds to S106. As starting conditions, the predetermined angle θ0 was small, the first predetermined amount BV0 was small, the first predetermined distance FL0 was large, and the second predetermined distance BL0 was large. Further, the release conditions were set such that the predetermined time T0 was large, the second predetermined amount AV0 was large, and the third predetermined amount CV0 was small. The target braking force was set large.

  On the other hand, in S100, when the driver's arousal level has not decreased (S100, NO), the process proceeds to S104, where the setting changing unit 12 initializes the start condition and the release condition of the hill hold control, and the target braking force, The process proceeds to S106.

  In S106, the braking force control unit 13 monitors whether the vehicle speed V of the vehicle is equal to or less than a predetermined value V0. The predetermined value V0 is a value that takes into account the measurement error of the vehicle speed V, and may be substantially zero. If the vehicle speed V exceeds the predetermined value V0 (S106, NO), since the vehicle is not stopped, the hill hold control is unnecessary and the current process is terminated. If the vehicle speed V is less than or equal to the predetermined value V0 (S106, YES), it is determined that the vehicle is stopped and the process proceeds to S108.

  In S108, the braking force control unit 13 checks whether or not the road surface gradient is equal to or greater than a predetermined angle θ0. When the road surface gradient is less than the predetermined angle θ0 (S108, NO), the road surface gradient is gentle and there is no possibility that the host vehicle slides down due to the influence of gravity. Is done. On the other hand, when the road surface gradient is equal to or greater than the predetermined angle θ0 (S108, YES), the process proceeds to S110.

  In S110, the braking force control unit 13 monitors whether the road gradient is a downward gradient or an upward gradient. If the road gradient is a downward gradient (S110, YES), the process proceeds to S112. On the other hand, in the case of an ascending slope (S110, NO), the process proceeds to S114.

  In S112, the braking force control unit 13 checks whether or not the inter-vehicle distance FL with the preceding vehicle is within the first predetermined distance FL0. When the inter-vehicle distance FL exceeds the first predetermined distance FL0 (S112, NO), the inter-vehicle distance FL is sufficient and there is no possibility of coming into contact with the preceding vehicle due to the own vehicle slipping down. This process is terminated. On the other hand, when the inter-vehicle distance FL is within the first predetermined distance FL0 (S112, YES), the process proceeds to S116.

  In S114, the braking force control unit 13 checks whether the inter-vehicle distance BL with the following vehicle is within the second predetermined distance BL0. When the inter-vehicle distance BL exceeds the second predetermined distance BL0 (S114, NO), since the inter-vehicle distance BL is sufficient, there is no possibility of coming into contact with the following vehicle due to the own vehicle slipping down. This processing is terminated. On the other hand, when the inter-vehicle distance BL is within the second predetermined distance BL0 (S114, YES), the process proceeds to S116.

  In S116, the braking force control unit 13 checks whether or not the brake operation amount BV is equal to or greater than the first predetermined amount BV0. When the brake operation amount BV is less than the first predetermined amount BV0 (S116, NO), no braking force to be held is generated, so that the hill hold control is unnecessary and the current process is terminated. On the other hand, when the brake operation amount BV is greater than or equal to the first predetermined amount BV0 (S116, YES), it is determined that the brake operation has started, and the process proceeds to S118.

  In S118, the braking force control unit 13 supplies power to the electromagnetic coil inside the holding valve 32, and closes the holding valve 32 to start the hill hold control, and proceeds to S120 in FIG. . When the target braking force is set to be large (that is, when the driver's arousal level is low), the braking force control unit 13 closes the holding valve 32 in addition to the hydraulic pump. 35 is driven to increase the wheel cylinder pressure Ph based on the target braking force (target wheel cylinder pressure).

  In S120 of FIG. 4, the warning notification unit 14 notifies a warning outside the vehicle, and the communication control unit 16 transmits a warning to the other vehicle. In addition, the warning alerting | reporting part 14 may alert | report a warning with respect to a driver | operator via the display and speaker (not shown) provided in the vehicle interior of the own vehicle.

  In S122, the braking force control unit 13 checks whether or not the elapsed time T after the release of the brake operation is equal to or longer than a predetermined time T0. Generally, when starting the running of the vehicle, the driver performs an accelerator operation after releasing the brake operation. Accordingly, if the elapsed time T is equal to or longer than the predetermined time T (S122, YES), the vehicle is predicted to start running, so the process proceeds to S128, the hill hold control is canceled, and the current process is terminated. On the other hand, when the elapsed time T is less than the predetermined time T0 (S122, NO), the process proceeds to S124.

  In S124, the braking force control unit 13 checks whether or not the accelerator operation amount AV is equal to or greater than the second predetermined amount AV0. If the accelerator operation amount AV is greater than or equal to the second predetermined amount AV0 (S124, YES), it is determined that the vehicle has started traveling, the process proceeds to S128, the hill hold control is canceled, and the current process ends. On the other hand, when the accelerator operation amount AV is less than the second predetermined amount AV0 (124, NO), the process proceeds to S126.

  In S126, the braking force control unit 13 checks whether or not the clutch operation amount CV is equal to or smaller than a third predetermined amount CV0. Generally, in a manual transmission (MT) vehicle, when the vehicle starts to travel, the driver releases the clutch operation after releasing the brake operation. If the clutch operation amount (clutch pedal depression amount) CV is equal to or smaller than the third predetermined amount CV0 (S126, YES), the vehicle is predicted to start running, so the process proceeds to S128 to cancel the hill hold control and This process is terminated. On the other hand, when the clutch operation amount CV exceeds the third predetermined amount CV0 (S126, NO), the process returns to S122, and the processing after S122 is continued.

  When the vehicle subject to hill hold control is an automatic transmission (AT) vehicle, S126 is naturally unnecessary, and when the accelerator operation amount AV is less than the second predetermined amount AV0 in S124 (NO in S124). , The process returns to S122, and the processes after S122 are continued.

  As described above, according to the vehicle control device of the present embodiment, when the decrease in the driver's arousal level is detected, the start condition or release condition of the hill hold control or the target braking force is changed. When the arousal level is low, it is possible to prevent the vehicle that is stopped on the slope from dropping due to gravity. Thus, contact with pedestrians and other vehicles can be prevented.

  As mentioned above, although one embodiment of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various modifications and substitutions can be made to the above-described embodiment without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the braking force control unit 13 supplies the electric power to the electromagnetic coil inside the holding valve 32 and keeps the wheel cylinder pressure Ph by closing the holding valve 32. However, the present invention is not limited to this. For example, when a hydraulic pump is provided on the upstream side of the holding valve 32 and the check valve 34, the braking force control unit 13 opens the holding valve 32 and drives the hydraulic pump so that the wheel cylinder The pressure Ph may be maintained.

  In the above-described embodiment, the start condition (4) is that the inter-vehicle distance FL between the host vehicle and the preceding vehicle is within the first predetermined distance FL0 when the road surface gradient is a downward gradient. In addition, the vehicle speed FV of the preceding vehicle may be a predetermined value FV0 or less. This is because when the vehicle speed FV of the vehicle ahead exceeds the predetermined value FV0, the vehicle ahead has already started running, and there is a low possibility that it will come into contact with the vehicle ahead due to the vehicle falling down.

  In the above-described embodiment, the release condition (1) is that the elapsed time T after release of the brake operation is equal to or greater than the predetermined time T0, but instead, the elapsed time after the start of the brake operation. T may be a predetermined time T0 or more. Whether or not the brake operation is started is determined based on the brake operation amount BV, and it is determined that the brake operation is started when the brake operation amount BV is equal to or greater than the first predetermined amount BV0.

  In the above-described embodiment, when a decrease in the driver's arousal level is detected as the release condition, the predetermined time T0 is set large, the second predetermined amount AV0 is large, and the third predetermined amount CV0 is set small. However, the present invention is not limited to this. For example, when a decrease in the driver's arousal level is detected as the release condition, the fourth predetermined amount BV1 may be set small. When the driver's arousal level is reduced, the stepping back operation of the brake pedal 22 may become slow, so the fourth predetermined amount BV1 is set small. Accordingly, when the driver's arousal level is reduced, it is possible to prevent the vehicle that is stopped on the slope from sliding down due to gravity, and to prevent contact with a pedestrian or another vehicle.

10 ECU
11 Arousal level detection unit (wake level detection means)
12 Setting change section (setting change means)
13 Braking force control unit (braking force control means)
14 Warning notification section (Warning notification means)
15 Communication control unit (communication control means)
DESCRIPTION OF SYMBOLS 20 Brake apparatus 32 Holding valve 34 Check valve 35 Hydraulic pump 40 Various sensors 50 Driver monitor camera 60 Road surface gradient detection sensor 70 Distance sensor 82 Hazard lamp 84 Horn 86 Communication apparatus

Claims (9)

In the vehicle control device that performs control capable of maintaining the braking force of the vehicle after releasing the brake operation,
Wakefulness detection means for detecting the driver's wakefulness,
A vehicle control device comprising: a setting change unit that changes a start condition or a release condition of the control or a target braking force when the arousal level detection unit detects a decrease in a driver's arousal level. The start condition includes that the road surface gradient is a predetermined angle or more,
The vehicle control device according to claim 1, wherein the setting change unit sets the predetermined angle to be small when the arousal level detection unit detects a decrease in the driver's arousal level. The start condition includes that the brake operation amount is equal to or greater than a first predetermined amount,
3. The vehicle control device according to claim 1, wherein the setting change unit sets the first predetermined amount to be small when the arousal level detection unit detects a decrease in the driver's arousal level. 4. The start condition includes that the inter-vehicle distance between the host vehicle and the preceding vehicle is within a first predetermined distance when the road surface slope is a downward slope. The vehicle control device according to any one of claims 1 to 3, wherein the first predetermined distance is set large when a decrease in the degree is detected. The start condition includes that an inter-vehicle distance between the host vehicle and the following vehicle is within a second predetermined distance when the road surface gradient is an uphill gradient. The vehicle control device according to any one of claims 1 to 4, wherein the second predetermined distance is set large when a decrease in the degree is detected. The release condition includes an elapsed time after release of the brake operation being a predetermined time or more,
The vehicle control device according to any one of claims 1 to 5, wherein the setting change unit sets the predetermined time to be large when the arousal level detection unit detects a decrease in the driver's arousal level. The release condition includes that the accelerator operation amount is equal to or greater than a second predetermined amount,
The vehicle control device according to any one of claims 1 to 6, wherein the setting change unit sets the second predetermined amount large when the arousal level detection unit detects a decrease in the driver's arousal level. The release condition includes that the clutch operation amount is equal to or less than a third predetermined amount,
The vehicle control device according to any one of claims 1 to 7, wherein the setting changing unit sets the third predetermined amount to be small when the arousal level detection unit detects a decrease in the driver's arousal level.   The vehicle control device according to any one of claims 1 to 8, wherein the setting change unit sets the target braking force to be large when the arousal level detection unit detects a decrease in the driver's arousal level.

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