Vehicle control device

Abstract

A vehicle control device is provided with: an automatic brake control unit that performs automatic brake control for applying a braking force to a host vehicle and automatically stopping the host vehicle; a stop / hold control unit that implements stop / hold control for holding the vehicle in a stopped state by applying a braking force to the vehicle in the stopped state by the automatic brake control unit; and a stop-holding release control unit that, when the stop-holding control is implemented, terminates the stop-holding control and releases the stop-holding state of the vehicle when a predetermined stop-holding release condition is satisfied. The driver condition acquisition unit acquires a driver condition, which is a condition of a driver of the vehicle, and the stop-hold release control unit changes a stop-hold release condition in accordance with the driver condition acquired by the driver condition acquisition unit.

Description

Technical Field

[0001] The present disclosure relates to a control device for a vehicle. Background Art

[0002] For example, Japanese Unexamined Patent Application Publication No. 2021-109504 discloses the following device: the vehicle is stopped by automatic braking, stop hold control for holding the stopped vehicle in a stopped state is implemented, and when a predetermined time has elapsed since the start of the stop hold control, the stop hold control is ended to release the stop hold state of the vehicle. Summary of the Invention

[0003] If the stop hold control is uniformly ended based on "a predetermined time has elapsed since the start of the stop hold control", there is a possibility of secondary damage occurring due to the release of the stop hold when the driver of the vehicle cannot appropriately grasp the surrounding information.

[0004] The present disclosure has been made to solve the above problems. That is, one of the objects of the present disclosure is to effectively reduce the risk of occurrence of secondary damage caused by the release of the stop hold.

[0005] The control device for a vehicle according to the present disclosure includes:

[0006] An automatic braking unit that, when it is determined that a predetermined automatic stop condition is satisfied, implements automatic braking control to apply a braking force to the vehicle itself to automatically stop the vehicle itself;

[0007] A stop hold unit that implements stop hold control to hold the vehicle itself in a stopped state by applying a braking force to the vehicle itself so that the vehicle itself that has been stopped by the automatic braking unit neither moves forward nor backward; and

[0008] A stop hold release unit that, when the stop hold control is being implemented by the stop hold unit, ends the stop hold control to release the stop hold state of the vehicle itself when a predetermined stop hold release condition is satisfied,

[0009] The control device for the vehicle includes a driver condition acquisition unit that acquires the condition of the driver of the vehicle itself, that is, the driver condition,

[0010] The stop hold release unit changes the stop hold release condition according to the driver condition acquired by the driver condition acquisition unit. Brief Description of the Drawings

[0011] Hereinafter, the features, advantages, and technical and industrial significance of the exemplary embodiments of the present invention will be described with reference to the drawings, in which the same reference numerals denote the same elements, and in which:

[0012] Figure 1 is a schematic diagram showing the hardware configuration of a vehicle according to the present embodiment;

[0013] Figure 2 is a schematic diagram showing the software configuration of the control device involved in this embodiment;

[0014] Figure 3 This is a flowchart for explaining a routine of stop and hold control and a process for releasing the stop and hold control executed by the control device according to the present embodiment. DETAILED DESCRIPTION

[0015] Hereinafter, a vehicle control device according to the present embodiment will be described with reference to the drawings.

[0016] Hardware composition

[0017] Figure 1 Schematic diagram showing the hardware configuration of the vehicle SV according to the present embodiment. Hereinafter, the vehicle SV may also be referred to as the own vehicle when it is necessary to distinguish it from other vehicles or the like.

[0018] The vehicle SV has an ECU (Electronic Control Unit) 10. The ECU 10 includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an interface device 14, and the like. The CPU 11 is a processor that executes various programs stored in the ROM 12. The ROM 12 is a non-volatile memory that stores data and the like required for the CPU 11 to execute various programs. The RAM 13 is a volatile memory that provides a work area that is expanded when various programs are executed by the CPU 11. The interface device 14 is a communication device for communicating with an external device.

[0019] ECU10 is a device that serves as a hub for driving assistance such as Pre-Crash Safety Control (hereinafter referred to as PCS control). Driving assistance is a concept that includes automatic driving. An internal sensor device 20, an external sensor device 30, a drive device 40, a steering device 41, a brake device 50, a driver monitoring device 60, and an HMI (Human Machine Interface) 90 are connected to ECU10 in a communicative manner.

[0020] The in-vehicle sensor device 20 is a group of sensors that acquire the state of the vehicle SV. The in-vehicle sensor device 20 includes a vehicle speed sensor 21, an accelerator sensor 22, a brake sensor 23, a steering angle sensor 24, a steering torque sensor 25, a yaw rate sensor 26, and the like.

[0021] The vehicle speed sensor 21 detects the traveling speed (vehicle speed V) of the vehicle SV. The accelerator sensor 22 detects the operation amount of an accelerator pedal (not shown) by the driver. The brake sensor 23 detects the operation amount of a brake pedal (not shown) by the driver. The steering angle sensor 24 detects the rotation angle (steering angle) of a steering wheel or a steering shaft (not shown). The steering torque sensor 25 detects the rotation torque (steering torque) of a steering wheel or a steering shaft (not shown). The yaw rate sensor 26 detects the yaw rate of the vehicle SV. The in-vehicle sensor device 20 transmits the state of the vehicle SV detected by each of the sensors 21 to 26 to the ECU 10 at a predetermined cycle.

[0022] The external sensor device 30 is a group of sensors that identify target object information related to target objects around the vehicle SV. The external sensor device 30 includes a radar sensor 31, a camera (imaging) sensor 32, and the like. Here, as the target object information, for example, surrounding vehicles, white lines on the road, signs, etc. can be cited.

[0023] The radar sensor 31 detects target objects existing around the vehicle SV. The radar sensor 31 includes a millimeter-wave radar and / or a lidar. The millimeter-wave radar emits millimeter-wave band radio waves and receives the millimeter waves reflected by target objects existing within the emission range. The millimeter-wave radar obtains the relative distance, relative speed, etc. between the vehicle SV and the target object based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, and the time from transmitting the millimeter waves to receiving the reflected waves. The lidar sequentially scans pulsed laser light having a wavelength shorter than that of millimeter waves in multiple directions, and obtains the shape of the target object detected in front of the vehicle SV, the relative distance, relative speed, etc. between the vehicle SV and the target object by receiving the reflected light reflected by the target object.

[0024] The camera sensor 32 captures images of the surroundings of the vehicle SV, and obtains target object information around the vehicle SV by processing the captured image data. As the camera sensor 32, for example, a digital camera having an imaging element such as a CMOS or a CCD can be used. The target object information is information indicating the type of the target object detected around the vehicle SV, the relative distance, relative speed, etc. between the vehicle SV and the target object. The type of the target object can be identified, for example, by machine learning such as pattern matching.

[0025] The external sensor device 30 repeatedly transmits the acquired target information to the ECU 10 at predetermined time intervals. The external sensor device 30 does not necessarily need to include both the radar sensor 31 and the camera sensor 32, and may include only the radar sensor 31 or only the camera sensor 32, for example.

[0026] The drive device 40 generates a driving force to be transmitted to the driving wheels of the vehicle SV. As the drive device 40, for example, an electric motor and an engine can be cited. The vehicle SV can be any one of a hybrid electric vehicle, a plug-in hybrid vehicle, a fuel cell electric vehicle, a battery electric vehicle, and an engine vehicle. The steering device 41 applies a steering force to the wheels of the vehicle SV.

[0027] The brake device 50 is, for example, a disc brake device, which applies a braking force to the wheels of the vehicle SV. The brake device 50 includes a brake actuator 51, a brake mechanism 52, and the like. The brake actuator 51 is provided in a hydraulic circuit between a master cylinder (not shown) that pressurizes the working oil by the pedal force of the brake pedal and the brake mechanism 52. The brake mechanism 52 includes a brake disc 53 fixed to the wheel and a brake caliper 54 fixed to the vehicle body. The brake actuator 51 adjusts the hydraulic pressure supplied to the wheel cylinder built into the brake caliper 54 according to instructions from the ECU 10, and operates the wheel cylinder by the hydraulic pressure. As a result, the brake actuator 51 presses the brake pad against the brake disc 53 to generate a friction braking force. In addition, the brake device 50 may also be a drum brake device, and the like.

[0028] The driver monitoring device 60 is a device for obtaining the state of the driver of the vehicle SV, and is provided with a driver camera 61, for example. The driver camera 61 mainly captures the driver's face, and detects the driver's facial orientation, line of sight, eye opening state, etc. based on the captured facial image. The driver monitoring device 60 sends the driver's state (hereinafter referred to as driver state information) obtained based on the detection result of the driver camera 61 to the ECU 10 at a predetermined period. In addition, the driver monitoring device 60 is not limited to the driver camera 61, and may also include other sensors that can obtain the driver's state information, such as a physiological measuring device for detecting the driver's heart rate and pulse rate, and a seat sensor for detecting the driver's seat.

[0029] The HMI90 is an interface for input and output of information between the ECU10 and the driver, and is equipped with an input device and an output device. Examples of the input device include a touch panel, a switch, a sound collection microphone, etc. Examples of the output device include a display device 91, a speaker 92, etc. The display device 91 is, for example, a center display, a multi-information display, a head-up display, etc. The speaker 92 is, for example, a speaker of an audio system or a navigation system.

[0030] Software configuration

[0031] Figure 2 It is a schematic diagram showing the software configuration of the control device according to this embodiment.

[0032] As Figure 2 shown, the ECU10 has functional elements such as a driver condition determination unit 100, a PCS control unit 110, a stop hold control unit 120, a stop hold release control unit 130, etc. The above-mentioned functional elements 100 to 130 are realized by the CPU11 of the ECU10 reading the program stored in the ROM12 into the RAM13 and executing it. In addition, all or part of the functional elements 100 to 130 may also be provided in another ECU separated (independent) from the ECU10, or an information processing device of a facility (such as a management center) capable of communicating with the vehicle SV.

[0033] The driver condition determination unit 100 determines whether the driver is in an abnormal state where the vehicle SV cannot be driven normally due to looking aside (side vision), drowsiness, confusion (panic), etc., based on the driver state information sent from the driver monitoring device 60. The driver condition determination unit 100 obtains, for example, the driver's line of sight direction, eye opening state, etc., based on the driver state information sent from the driver monitoring device 60. The driver condition determination unit 100 determines the driver to be in an abnormal state when the state where the driver's line of sight direction deviates from a predetermined range including the front of the vehicle SV, the state where the driver's eyes are closed, etc. continues for a predetermined time. When the driver condition determination unit 100 determines the driver to be in an abnormal state, it sends a "driver abnormal signal" indicating that the driver is in an abnormal state to the stop hold release control unit 130 described later.

[0034] The PCS control unit 110 performs PCS control for avoiding a collision between the host vehicle SV and a preceding target object or reducing the damage caused by the collision. The PCS control unit 110 acquires the coordinate information of an object existing in front of the host vehicle SV based on the target object information transmitted from the external sensor device 30. In addition, the PCS control unit 110 calculates the turning radius of the host vehicle SV based on the detection results of the vehicle speed sensor 21, the steering angle sensor 24, and the yaw rate sensor 26, and calculates the trajectory of the host vehicle SV based on the turning radius. The PCS control unit 110 determines whether a moving object and a stationary object in front of the host vehicle SV are obstacles that may collide with the host vehicle SV. When the object is a moving object, the PCS control unit 110 calculates the trajectory of the moving object based on the coordinate information of the moving object, and determines the moving object as an obstacle when the trajectory of the moving object intersects the trajectory of the host vehicle SV. In addition, when the object is a stationary object, the PCS control unit 110 determines the stationary object as an obstacle when the trajectory of the host vehicle SV intersects the current position of the stationary object.

[0035] When the PCS control unit 110 determines an object as an obstacle, it calculates the time to collision (hereinafter referred to as TTC) until the host vehicle SV collides with the obstacle based on the distance L from the host vehicle SV to the obstacle and the relative speed Vr of the obstacle with respect to the host vehicle SV. TTC is an index value indicating the possibility of a collision between the host vehicle SV and the obstacle. TTC can be obtained by dividing the distance L from the host vehicle SV to the obstacle by the relative speed Vr (TTC = L / Vr). When TTC is equal to or less than a predetermined determination threshold, the PCS control unit 110 determines that the possibility of a collision between the host vehicle SV and the obstacle is high. When the PCS control unit 110 determines that the possibility of a collision is high, it performs an alarm based on the speaker 92 and / or the display device 91, and performs automatic braking control. The automatic braking control is a control for decelerating the host vehicle SV in such a manner that the deceleration of the host vehicle SV matches a predetermined target deceleration by controlling the operation of the brake actuator 51. Thus, the host vehicle SV can be forcibly decelerated without the driver's brake pedal operation.

[0036] When the host vehicle SV stops due to the automatic braking control by the PCS control unit 110, the stop hold control unit 120 controls the operation of the brake actuator 51 so as to hold the host vehicle SV in a stopped state (the host vehicle SV neither moves forward nor backward). When the stop hold control unit 120 confirms that the vehicle SV has stopped due to the automatic braking control, it controls the operation of the brake actuator 51 and supplies the hydraulic pressure set for stop hold to the wheel cylinders of the brake mechanism 52. Thereby, the stopped state of the host vehicle SV is maintained. Hereinafter, "maintaining the stopped state of the host vehicle SV" is referred to as "stop hold", and "the braking force control for maintaining the stopped state of the host vehicle SV" is referred to as "stop hold control".

[0037] The stop hold release control unit 130 determines whether a preset release condition is satisfied. When the release condition is satisfied, it ends the control of the brake actuator 51 for stop hold by the stop hold control unit 120. The release condition for stop hold is satisfied, for example, when the duration T of the stop hold control reaches a predetermined set time Tref1. The set time Tref1 is not particularly limited and is, for example, several seconds. When the release condition for stop hold is satisfied, the stop hold release control unit 130 releases the stop hold of the host vehicle SV by ending the stop hold control.

[0038] Here, if the stop hold control is uniformly ended based on "the satisfaction of the release condition for stop hold", that is, "the duration T of the stop hold control reaches the set time Tref1", there is a possibility of occurrence of secondary damage in the case where the driver of the host vehicle SV is in an abnormal state where the driver cannot appropriately grasp the surrounding information. When the stop hold release control unit 130 receives a driver abnormality signal from the driver condition determination unit 100, it makes it difficult for the release condition for stop hold to be satisfied. Specifically, when the stop hold release control unit 130 receives a driver abnormality signal from the driver condition determination unit 100, it changes the release condition for stop hold by extending the set time Tref1 by a predetermined time. Hereinafter, the changed set time is referred to as the changed set time Tref2. Thereby, in the case where the driver has an abnormality, the duration of continuous execution of the stop hold control is extended, and the risk of occurrence of secondary damage can be effectively reduced.

[0039] Figure 3 It is a flowchart of a routine for explaining the stop hold control and the release process of the stop hold control executed by the CPU 11 of the ECU 10. Figure 3 The illustrated routine starts when performing the automatic braking control based on the PCS control.

[0040] In S100, the ECU 10 determines whether the vehicle SV has stopped due to the automatic braking control of the PCS. If the vehicle SV has stopped (Yes), the ECU 10 proceeds to the process of S110. On the other hand, if the vehicle SV has not stopped (No), the ECU 10 repeatedly makes the determination in S100.

[0041] In S110, the ECU 10 controls the operation of the brake actuator 51 to perform stop-holding control for keeping the vehicle SV in a stopped state. Then, in S120, the ECU 10 determines whether the driver is in an abnormal state where the vehicle SV cannot be driven normally. If the driver is in an abnormal state (Yes), the ECU 10 proceeds to the process of S130. On the other hand, if the driver is not in an abnormal state (No), the ECU 10 proceeds to the process of S150.

[0042] In S150, the ECU 10 determines whether the duration T of the stop-holding control has reached the set time Tref1. If the duration T has reached the set time Tref1 (Yes), the ECU 10 proceeds to the process of S170. On the other hand, if the duration T has not reached the set time Tref1 (No), the ECU 10 repeatedly makes the determination in S150.

[0043] When proceeding from S120 to the process of S130, the ECU 10 sets the changed set time Tref2 by extending the set time Tref1 by a predetermined time. Then, in S140, the ECU 10 determines whether the duration T of the stop-holding control has reached the changed set time Tref2. If the duration T has reached the changed set time Tref2 (Yes), the ECU 10 proceeds to the process of S170. On the other hand, if the duration T has not reached the changed set time Tref2 (No), the ECU 10 repeatedly makes the determination in S140.

[0044] In S170, the ECU 10 releases the stop-holding of the vehicle SV by ending the stop-holding control, and then returns this routine.

[0045] As described above, the control device for a vehicle according to this embodiment has been described, but the present disclosure is not limited to the above embodiment, and various modifications can be made without departing from the purpose of the present disclosure. For example, in the above embodiment, the automatic braking control of the PCS is taken as an example for description, but the technology of the present disclosure can also be applied to the release of the stop-holding control that operates when the vehicle SV stops due to an automatic braking control other than the PCS control. In addition, the technology of the present disclosure can also be applied to an autonomous driving vehicle that automatically performs part or all of the driving operations.

Claims

1. A vehicle control device, comprising: an automatic braking unit that, when it is determined that a predetermined automatic stop condition is satisfied, performs automatic braking control for applying a braking force to the host vehicle to automatically stop the host vehicle; a stop holding unit that performs stop holding control for holding the host vehicle in a stopped state by applying a braking force to the host vehicle in such a manner that the host vehicle stopped by the automatic braking unit neither moves forward nor moves backward; and a stop holding release unit for releasing the stop holding state of the host vehicle by terminating the stop holding control when a predetermined stop holding release condition is satisfied while the stop holding control is being implemented by the stop holding unit; The control device of the vehicle includes a driver status acquisition unit, the driver status acquisition unit acquires the driver status of the driver of the host vehicle, The stop and hold release unit changes the stop and hold release condition according to the driver condition acquired by the driver condition acquisition unit.

2. The vehicle control device according to claim 1, When the driver condition acquisition unit acquires that the driver is in an abnormal state in which the driver cannot normally drive the host vehicle, the stop hold release unit makes it more difficult for the stop hold release condition to be satisfied than when the abnormal state is not acquired.

3. The vehicle control device according to claim 2, The stop and hold release condition is a condition that is satisfied when the duration of the stop and hold control reaches a predetermined time. The stop and hold release unit makes it difficult for the stop and hold release condition to be satisfied by extending the predetermined time compared to a case where the abnormal state is not acquired when the driver condition acquisition unit acquires the abnormal state.

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