Vehicle control device

Abstract

To provide a control device for a vehicle, capable of inhibiting a situation where acceleration is suppressed at the start of the vehicle, so that emergency avoidance cannot be performed.SOLUTION: There is provided a control device for a vehicle including an automated brake hold apparatus which maintains brake force even after the operation of a brake pedal is released when the vehicle is stopped, and which releases the brake force by the operation of an accelerator pedal. The control device suppresses engine torque (torque suppression) until the brake force by the automated brake hold apparatus is released when it is determined that emergency avoidance is not necessary, and prohibits the suppression of the engine torque when it is determined that the emergency avoidance is necessary.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle.

Background Art

[0002] Conventionally, a braking maintenance control device releases the maintenance of the vehicle's braking when the idling stop condition is released, and an idling stop device restarts the engine in response to an accelerator operation by the driver, and controls the engine torque so that the engine torque becomes equal to or less than a predetermined value until the release of the braking maintenance is completed. A technique has been proposed in Patent Document 1.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional technology as proposed in Patent Document 1, since the engine torque is increased after the release of the braking maintenance is completed, the acceleration at the time of vehicle start is suppressed. For this reason, in the conventional technology, even when the driver tries to perform an emergency avoidance when another vehicle is approaching or there is a possibility of contact by a suspicious person, the acceleration is suppressed at the time of vehicle start and the emergency avoidance cannot be performed.

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a control device for a vehicle that can prevent the acceleration from being suppressed at the time of vehicle start and prevent the emergency avoidance from being impossible.

Means for Solving the Problems

[0006] The vehicle control device according to the present invention is a vehicle control device provided with an auto brake hold device that maintains braking force even after the operation of the brake pedal is released when the vehicle stops, and releases the braking force by operating the accelerator pedal. Determine whether there is an approach of another vehicle to the vehicle or contact by a suspicious person, and if it is determined that there is an approach of another vehicle to the vehicle or contact by a suspicious person, determine that emergency avoidance is necessary It includes an emergency avoidance determination unit, automatically stops the engine when it is determined that the idle stop condition is satisfied, restarts the engine when it is determined that the accelerator pedal is being operated, and releases the braking force when the startable condition that allows the vehicle to start with the driving force of the engine is satisfied to control the auto brake hold device, suppresses engine torque until the braking force by the auto brake hold device is released when it is determined by the emergency avoidance determination unit that emergency avoidance is not necessary, and prohibits the suppression of engine torque when it is determined by the emergency avoidance determination unit that emergency avoidance is necessary. It has a configuration including a control unit.

Effects of the Invention

[0007] The present invention can provide a vehicle control device that can prevent acceleration from being suppressed during vehicle start-up and prevent the inability to perform emergency avoidance.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0009] A vehicle control device according to an embodiment of the present invention is a vehicle control device provided with an autobrake hold device that maintains braking force even after the operation of the brake pedal is released when the vehicle stops and releases the braking force by operating the accelerator pedal. The vehicle control device includes an emergency avoidance determination unit that determines whether emergency avoidance is necessary, and a control unit that controls to suppress engine torque until the braking force by the autobrake hold device is released when the emergency avoidance determination unit determines that emergency avoidance is not necessary, and prohibits the suppression of engine torque when the emergency avoidance determination unit determines that emergency avoidance is necessary. Thus, the vehicle control device according to an embodiment of the present invention can prevent acceleration from being suppressed during vehicle start and prevent the vehicle from being unable to perform emergency avoidance.

Example

[0010] Hereinafter, a vehicle equipped with a vehicle control device according to an embodiment of the present invention will be described with reference to the drawings.

[0011] As shown in FIG. 1, the vehicle 1 includes an engine 2, an engine controller 3, a brake pedal 4, a booster 5, a master cylinder 6, a brake pressure holding device 7, front wheels 8, rear wheels 9, an electric parking brake 10, an accelerator pedal 11, and a control device 12.

[0012] The engine 2 has a plurality of cylinders formed therein. In the present embodiment, the engine 2 is configured to perform a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke for each cylinder.

[0013] By performing a series of four strokes, the engine 2 rotates either the front wheels 8 and the rear wheels 9 or one of the front wheels 8 and the rear wheels 9 via a transmission mechanism and a differential mechanism (not shown).

[0014] The engine controller 3 is composed of a computer unit including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory for storing backup data and the like, an input port, an output port, and a communication module.

[0015] In the ROM of this computer unit, a program for causing the computer unit to function as the engine controller 3 is stored together with various constants and various maps.

[0016] That is, when the CPU executes the program stored in the ROM using the RAM as a work area, this computer unit functions as the engine controller 3 in the present embodiment.

[0017] The engine controller 3 is connected to an in-vehicle LAN (Local Area Network) conforming to a standard such as CAN (Controller Area Network) via a communication module. The engine controller 3 is connected to the control device 12 via the in-vehicle LAN.

[0018] The engine controller 3 controls the operating state of the engine 2 by controlling the intake air amount, fuel injection amount, ignition timing, etc. of the engine 2 based on the detection signals input via the input port from various sensors and the control signals output from the control device 12.

[0019] The booster device 5 assists the depressing force of the brake pedal 4 using, for example, the negative pressure generated inside the engine 2. The master cylinder 6 generates a hydraulic pressure corresponding to the depressing force of the brake pedal 4 via the booster device 5.

[0020] The brake pressure holding device 7 is constituted by a hydraulic circuit that creates a brake pressure for braking the front wheels 8 and the rear wheels 9 from the hydraulic pressure generated by the master cylinder 6. The brake pressure holding device 7 can hold the brake pressure under the control of the control device 12 regardless of the hydraulic pressure generated by the master cylinder 6. The electric parking brake 10 generates a braking force for the rear wheels 9 under the control of the control device 12.

[0021] The control device 12 is constituted by a computer unit including a CPU, a RAM, a ROM, a flash memory for storing backup data and the like, an input port, an output port, and a communication module. In the ROM of this computer unit, a program for causing the computer unit to function as the control device 12 is stored together with various constants and various maps.

[0022] That is, when the CPU executes the program stored in the ROM using the RAM as a work area, this computer unit functions as the control device 12 in this embodiment.

[0023] Connected to the input port of the control device 12 are a brake switch 21 that detects whether or not the brake pedal 4 is depressed, an accelerator opening sensor 22 that detects the operation amount of the accelerator pedal 11 (hereinafter also referred to as "accelerator opening"), a vehicle speed sensor 23 that detects the vehicle speed, a master cylinder pressure sensor 24 that detects the hydraulic pressure generated by the master cylinder 6, and a camera 25 that captures the periphery of the vehicle 1.

[0024] Connected to the output port of the control device 12 are the brake pressure holding device 7 and the electric parking brake 10. The control device 12 is connected to the in-vehicle LAN via the communication module. The control device 12 is connected to the engine controller 3 via the in-vehicle LAN.

[0025] When the engine automatic stop condition is satisfied, the control device 12 outputs a control signal for automatically stopping the engine 2 to the engine controller 3, and when the engine restart condition is satisfied, the control device 12 outputs a control signal for restarting the engine 2 to the engine controller 3, functioning as an idle stop system. In this embodiment, the engine automatic stop condition is that the vehicle 1 has stopped, and the engine restart condition is that the accelerator pedal 11 has been depressed.

[0026] While the vehicle 1 is in a stopped state, after the brake pedal 4 is released and before the vehicle 1 can move forward by the driving force of the engine 2 restarted by depressing the accelerator pedal 11, the control device 12 executes auto brake hold control to prevent the vehicle 1 from creeping by causing the brake pressure holding device 7 to hold the brake pressure.

[0027] For example, while the vehicle 1 is in a stopped state, when the master cylinder pressure sensor 24 detects that the master cylinder pressure has become equal to or lower than a predetermined pressure, the control device 12 controls the brake pressure holding device 7 to hold the brake pressure.

[0028] When the startable condition for starting the vehicle 1 by the driving force of the engine 2 is satisfied, the control device 12 controls the brake pressure holding device 7 to reduce the brake pressure and release the brake. In this embodiment, the control device 12 and the brake pressure holding device 7 constitute an auto brake hold device.

[0029] During the execution period of the auto brake hold control, the control device 12 may prevent the vehicle 1 from creeping by the braking force of the electric parking brake 10. That is, the control device 12 and the electric parking brake 10 may constitute an auto brake hold device.

[0030] Also, during the execution period of the auto brake hold control, the control device 12 may cause the brake pressure holding device 7 to hold the brake pressure and prevent the vehicle 1 from slipping down due to the braking force of the electric parking brake 10. That is, the control device 12, the brake pressure holding device 7, and the electric parking brake 10 may be configured to form an auto brake hold device.

[0031] The control device 12 has a function as an emergency avoidance determination unit 12a that determines whether emergency avoidance is necessary. The control device 12 determines whether there is an approach of another vehicle to the vehicle 1 or contact by a suspicious person based on the image captured by the camera 25.

[0032] When the control device 12 determines that there is an approach of another vehicle to the vehicle 1 or contact by a suspicious person, it determines that emergency avoidance is necessary. When the control device 12 determines that there is no approach of another vehicle to the vehicle 1 or contact by a suspicious person, it determines that emergency avoidance is not necessary.

[0033] The control device 12 has a function as a control unit 12b that suppresses the output torque of the engine 2 (hereinafter, also referred to as "engine torque") according to the determination result of whether emergency avoidance is necessary.

[0034] In this embodiment, when the control device 12 determines that emergency avoidance is not necessary, it suppresses the output torque of the engine 2 (hereinafter, also referred to as "engine torque") until the torque suppression holding time after the braking force by the auto brake hold control is released elapses, and prohibits the suppression of the engine torque when it determines that emergency avoidance is necessary.

[0035] The torque suppression holding time is determined in advance by verification as the time from the end of the auto brake hold control to the release of the braking force by the auto brake hold control, and is stored in the ROM. In this embodiment, the torque suppression holding time is set to a time obtained by adding a predetermined time (for example, 100 ms) as a slight margin.

[0036] During the period of suppressing the engine torque, the control device 12 outputs a control signal for controlling the torque of the engine 2 to the engine controller 3 so that the engine torque does not exceed a predetermined upper limit torque. The upper limit torque is determined in advance by verification so that the vehicle 1 does not suddenly start when the braking force by the autobrake hold control is released, and is stored in the ROM.

[0037] Note that an inclination angle sensor for detecting the inclination angle in the traveling direction of the vehicle 1 may be provided in the vehicle 1, and the upper limit torque may be increased as the inclination angle detected by the inclination angle sensor increases. In the case of such a configuration, a map representing the upper limit torque with respect to the inclination angle may be stored in the ROM.

[0038] Further, during the period of suppressing the engine torque, instead of making the engine torque not exceed a predetermined upper limit torque, the control device 12 may output a control signal for controlling the engine 2 so that the increase amount of the engine torque per unit time does not exceed a predetermined upper limit increase amount to the engine controller 3.

[0039] The driving assistance operation of the control device 12 configured as described above will be described with reference to FIG. 2. Note that the driving assistance operation described below is repeatedly executed while the control device 12 is activated.

[0040] First, in S1, the control device 12 determines whether the vehicle 1 is stopped. For example, if the detection value of the vehicle speed sensor 23 is 0, the control device 12 determines that the vehicle 1 is stopped, and if the detection value of the vehicle speed sensor 23 is not 0, the control device 12 determines that the vehicle 1 is not stopped.

[0041] If it is determined in S1 that the vehicle 1 is stopped, the control device 12 executes the process of S2. If it is determined in S1 that the vehicle 1 is not stopped, the control device 12 executes the process of S1. That is, if it is determined in S1 that the vehicle 1 is not stopped, the control device 12 enters a state of waiting for the vehicle 1 to stop.

[0042] In S2, the control device 12 determines whether the execution condition of the autobrake hold control (hereinafter, also referred to as the "brake hold condition") is satisfied. For example, when the control device 12 determines that the vehicle 1 has stopped and an autobrake hold switch (not shown) provided on the instrument panel or the like is ON, it determines that the brake hold condition is satisfied. When it determines that the vehicle 1 has not stopped or the autobrake hold switch is OFF, it determines that the brake hold condition is not satisfied.

[0043] Note that an inclination angle sensor for detecting the inclination angle in the traveling direction of the vehicle 1 is provided on the vehicle 1. In S2, when the control device 12 determines that the vehicle 1 has stopped, the autobrake hold switch is ON, and the detection value of the inclination angle sensor is equal to or greater than a predetermined value, it determines that the brake hold condition is satisfied. When it determines that the vehicle 1 has not stopped, the autobrake hold switch is OFF, or the detection value of the inclination angle sensor is less than the predetermined value, it may be determined that the brake hold condition is not satisfied.

[0044] In S2, when it is determined that the brake hold condition is satisfied, the control device 12 executes the process of S4. In S2, when it is determined that the brake hold condition is not satisfied, the control device 12 executes the process of S3.

[0045] In S3, the control device 12 determines whether the accelerator pedal 11 is being operated based on the detection value of the accelerator opening sensor 22. In S3, when it is determined that the accelerator pedal 11 is being operated, the control device 12 ends the driving assistance operation, and the vehicle 1 starts moving. In S3, when it is determined that the accelerator pedal 11 is not being operated, the control device 12 executes the process of S2.

[0046] In S4, the control device 12 starts executing the auto brake hold control (denoted as "Brake Hold ON" in the figure). After executing the process of S4, the control device 12 executes the process of S5.

[0047] In S5, the control device 12 determines whether the idle stop condition is satisfied. For example, when the engine automatic stop condition described above is satisfied, the control device 12 determines that the idle stop condition is satisfied, and when the engine automatic stop condition is not satisfied, the control device 12 determines that the idle stop condition is not satisfied.

[0048] In S5, if it is determined that the idle stop condition is not satisfied, the control device 12 executes the process of S6. In S5, if it is determined that the idle stop condition is satisfied, the control device 12 executes the process of S7.

[0049] In S6, the control device 12 determines whether the accelerator pedal 11 is operated based on the detection value of the accelerator opening sensor 22. In S6, if it is determined that the accelerator pedal 11 is not operated, the control device 12 executes the process of S5. In S6, if it is determined that the accelerator pedal 11 is operated, the control device 12 executes the process of S12.

[0050] In S7, the control device 12 starts executing the idle stop. For example, the control device 12 outputs a control signal for automatically stopping the engine 2 to the engine controller 3. After executing the process of S7, the control device 12 executes the process of S8.

[0051] In S8, the control device 12 determines whether the accelerator pedal 11 is operated based on the detection value of the accelerator opening sensor 22. In S8, if it is determined that the accelerator pedal 11 is not operated, the control device 12 executes the process of S8.

[0052] That is, in S8, when it is determined that the accelerator pedal 11 is not being operated, the control device 12 enters a state of waiting for an operation of the accelerator pedal 11. In S8, when it is determined that the accelerator pedal 11 is being operated, the control device 12 executes the process of S9.

[0053] In S9, the control device 12 starts the engine 2. For example, the control device 12 outputs a control signal for restarting the engine 2 to the engine controller 3. After executing the process of S9, the control device 12 executes the process of S10.

[0054] In S10, the control device 12 determines whether the explosion complete condition of the engine 2 is satisfied. For example, when the above-described startable condition is satisfied, the control device 12 determines that the explosion complete condition of the engine 2 is satisfied, and when the startable condition is not satisfied, the control device 12 determines that the explosion complete condition of the engine 2 is not satisfied.

[0055] In S10, when it is determined that the explosion complete condition of the engine 2 is not satisfied, the control device 12 executes the process of S10. That is, in S10, when it is determined that the explosion complete condition of the engine 2 is not satisfied, the control device 12 enters a state of waiting for the explosion complete condition of the engine 2 to be satisfied. In S10, when it is determined that the explosion complete condition of the engine 2 is satisfied, the control device 12 executes the process of S11.

[0056] In S11, the control device 12 determines whether emergency avoidance is necessary. In S11, when the control device 12 determines that emergency avoidance is not necessary (YES), it executes the process of S13. In S11, when the control device 12 determines that emergency avoidance is necessary (NO), it executes the process of S12.

[0057] In S12, the control device 12 ends the execution of the auto brake hold control (denoted as "Brake Hold OFF" in the figure). When the execution of the auto brake hold control ends, the brake pressure decreases, so the vehicle 1 starts moving. After executing the process of S12, the control device 12 ends the driving assistance operation.

[0058] In S13, the control device 12 suppresses the engine torque (denoted as "Torque Suppression ON" in the figure). For example, the control device 12 outputs a control signal for suppressing the engine torque to the engine controller 3. After executing the process of S13, the control device 12 executes the process of S14.

[0059] In S14, the control device 12 ends the execution of the auto brake hold control (denoted as "Brake Hold OFF" in the figure). When the execution of the auto brake hold control ends, the brake pressure decreases, so the vehicle 1 starts moving. After executing the process of S14, the control device 12 executes the process of S15.

[0060] In S15, the control device 12 determines whether the above-mentioned torque suppression holding time has elapsed. In S15, if it is determined that the torque suppression holding time has not elapsed, the control device 12 executes the process of S15.

[0061] That is, in S15, if it is determined that the torque suppression holding time has not elapsed, the control device 12 enters a state of waiting for the torque suppression holding time to elapse. In S15, if it is determined that the torque suppression holding time has elapsed, the control device 12 executes the process of S16.

[0062] In S16, the control device 12 releases the suppression of the engine torque (denoted as "Torque Suppression OFF" in the figure). For example, the control device 12 outputs a control signal for releasing the suppression of the engine torque to the engine controller 3. After executing the process of S16, the control device 12 ends the driving assistance operation.

[0063] The operation of the driving assistance operation described above will be described with reference to FIG. 3. FIG. 3 shows changes in various detection values and various control values over time from a state where the vehicle 1 is stopped, the engine 2 is automatically stopped due to idling stop, and the auto brake hold control is being executed.

[0064] Each graph in FIG. 3(a) represents changes in various detection values and various control values over time when the control device 12 determines that emergency avoidance is not necessary, and each graph in FIG. 3(b) represents changes in various detection values and various control values over time when the control device 12 determines that emergency avoidance is necessary.

[0065] Also, in each of the left and right graphs in FIG. 3, as the various detection values and various control values, in order from the top, are vehicle speed, the engine speed of the engine 2 (hereinafter also referred to as "engine speed"), the determination result of the necessity of emergency avoidance, the accelerator opening, the suppression state of the engine torque (hereinafter also referred to as "torque suppression"), the output torque of the engine 2 (hereinafter also referred to as "actual torque"), the execution state of the auto brake hold control, and the brake pressure.

[0066] Hereinafter, based on each graph in FIG. 3(a), the operation of the driving assistance operation when the control device 12 determines that emergency avoidance is not necessary will be described.

[0067] When an operation of the accelerator pedal 11 based on the accelerator opening detected by the accelerator opening sensor 22 is detected at time t1, the engine speed and the actual torque start to increase. When the startable condition is satisfied at time t2, since it is determined that emergency avoidance is not necessary (False), the suppression state of the engine torque becomes effective (ON).

[0068] Also, when the startable condition is satisfied at time t2, the execution state of the auto brake hold control becomes OFF, and at time t3, the braking force by the auto brake hold control is released. When the execution state of the auto brake hold control becomes OFF, the brake pressure decreases and the vehicle speed starts to increase.

[0069] From time t2 until time t4 when the torque suppression holding time has elapsed, since the suppression state of the engine torque is valid (ON), the actual torque is suppressed, and along with the actual torque, the engine speed and the vehicle speed are suppressed.

[0070] At time t4, when the suppression state of the engine torque becomes invalid (OFF), since the suppression of the engine torque is released, the actual torque starts to increase, and along with the actual torque, the engine speed and the vehicle speed start to increase.

[0071] Hereinafter, based on each graph in Fig. 3(b), the operation of the driving assistance operation when it is determined by the control device 12 that emergency avoidance is necessary will be described.

[0072] At time t11, when an operation of the accelerator pedal 11 based on the accelerator opening detected by the accelerator opening sensor 22 is detected, the engine speed and the actual torque start to increase. At time t12, when the startable condition is satisfied, since it is determined that emergency avoidance is necessary (True), the suppression state of the engine torque is maintained as invalid (OFF).

[0073] Also, at time t12, when the startable condition is satisfied, the execution state of the auto brake hold control becomes OFF, and at time t13, the braking force by the auto brake hold control is released. When the execution state of the auto brake hold control becomes OFF, the brake pressure decreases, and the vehicle speed starts to increase.

[0074] After time t12, since the suppression state of the engine torque is maintained as invalid (OFF), the actual torque continuously increases, and along with the actual torque, the engine speed and the vehicle speed continuously increase.

[0075] As described above, when it is determined that emergency avoidance is necessary, the vehicle control device according to the present embodiment prohibits suppression of engine torque. Therefore, when there is a possibility of approach by another vehicle or contact by a suspicious person and the driver intends to perform emergency avoidance, acceleration at the time of vehicle start is not suppressed, and emergency avoidance can be performed.

[0076] Further, when it is determined that emergency avoidance is unnecessary, the vehicle control device according to the present embodiment suppresses engine torque until the braking force is released by the auto brake hold device. Therefore, when the driver does not intend to perform emergency avoidance, discomfort at the time of vehicle start can be suppressed.

[0077] Further, when it is determined that emergency avoidance is unnecessary, the vehicle control device according to the present embodiment suppresses engine torque until a predetermined time elapses after the braking force is released by the auto brake hold device. Therefore, when the driver does not intend to perform emergency avoidance, discomfort at the time of vehicle start can be surely suppressed.

[0078] In addition, in the present embodiment, the control device 12 has been described as determining whether there is an approach by another vehicle to the vehicle 1 or contact by a suspicious person based on the image captured by the camera 25.

[0079] On the other hand, the control device 12 may determine whether there is an approach by another vehicle to the vehicle 1 or contact by a suspicious person based on the detection value of a proximity sensor such as an ultrasonic sensor or a laser sensor.

[0080] Further, the control device 12 may determine whether there is an approach by another vehicle to the vehicle 1 or contact by a suspicious person based on the detection value of a contact detection sensor.

[0081] Further, the control device 12 may determine whether there is an approach by another vehicle to the vehicle 1 or contact by a suspicious person based on a combination of two or more of the image captured by the camera 25, the detection value of the proximity sensor, and the detection value of the contact detection sensor.

[0082] Although embodiments of the present invention have been disclosed, it is obvious that those skilled in the art can make changes without departing from the scope of the present invention. It is intended that all such modifications and equivalents be included in the following claims.

Explanation of Signs

[0083] 1 Vehicle 4 Brake Pedal 7 Brake Pressure Holding Device (Auto Brake Hold Device) 10 Electric Parking Brake (Auto Brake Hold Device) 12 Control Device (Auto Brake Hold Device) 12a Emergency Avoidance Judgment Unit 12b Control Unit

Claims

1. A vehicle control device comprising an auto brake hold device that maintains braking force even after the operation of the brake pedal is released when the vehicle is stopped and releases the braking force by operating the accelerator pedal, an emergency avoidance determination unit that determines whether there is an approach of another vehicle to the vehicle or contact by a suspicious person, and determines that emergency avoidance is necessary when it is determined that there is an approach of another vehicle to the vehicle or contact by a suspicious person, a control unit that automatically stops the engine when it is determined that the idle stop condition is satisfied, restarts the engine when it is determined that the accelerator pedal is being operated, controls the auto brake hold device to release the braking force when the startable condition that allows the vehicle to start with the driving force of the engine is satisfied, suppresses the engine torque until the braking force by the auto brake hold device is released when it is determined by the emergency avoidance determination unit that emergency avoidance is not necessary, and controls to prohibit the suppression of the engine torque when it is determined by the emergency avoidance determination unit that emergency avoidance is necessary; A vehicle control device characterized by comprising the above.

2. The vehicle control device according to claim 1, wherein the control unit controls to suppress the engine torque until a predetermined time elapses after the braking force by the auto brake hold device is released when it is determined by the emergency avoidance determination unit that emergency avoidance is not necessary.

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