JP6166704B2 - Vehicle braking control device - Google Patents

Description

  The present invention relates to a vehicle braking control device that controls a brake pressure that is automatically increased when a vehicle collides.

  Vehicles produced in recent years are equipped with a so-called automatic brake system that automatically increases the brake pressure before and after a vehicle collision regardless of the driver's operation. Currently, various technologies related to automatic braking systems have been developed. Patent Document 1 discloses a device that activates an automatic brake at the time of a collision and releases the automatic brake when an accelerator pedal operation amount exceeds a threshold value after a predetermined time has elapsed since the activation of the automatic brake.

  The apparatus of Patent Document 1 will be further described. An ECU (electronic control unit) that controls the automatic brake system counts the elapsed time after the automatic brake operation with a timer, and receives an accelerator pedal operation signal from the accelerator pedal operation amount sensor via a communication line. For example, when the time measured by the timer is equal to or longer than a predetermined time and the accelerator pedal operation signal indicates an operation of the accelerator pedal exceeding a predetermined amount, the ECU eliminates the brake pressure that has been automatically increased. Control the brake actuator.

  If there is a risk of a rear collision from a subsequent vehicle after a vehicle collision, it is better to release the automatic brake early and accelerate in the forward direction. According to the device of Patent Document 1, the automatic brake is operated for at least a predetermined time to ensure safety, and thereafter, the automatic brake can be released and accelerated by the operation of the accelerator pedal as a trigger.

Special table 2009-532790 gazette

  At the time of a vehicle collision, a communication abnormality may occur between the ECU and the accelerator pedal operation amount sensor due to the collision. In addition, a detection abnormality may occur in the accelerator pedal operation amount sensor itself. In such a case, an abnormality occurs in the accelerator pedal operation signal. Patent Document 1 does not assume that an abnormality occurs in the accelerator pedal operation signal. For this reason, when an abnormality occurs in the accelerator pedal operation signal, there is a possibility that even if the driver operates the accelerator pedal, the automatic brake is not released and acceleration cannot be performed.

  The present invention has been made in consideration of such problems, and provides a vehicle braking control device that can reliably release an automatic brake and accelerate a vehicle at an early stage even when an abnormality occurs in an accelerator pedal operation signal. With the goal.

  The present invention includes a brake pressure increasing unit that increases the brake pressure more than before the collision when a collision occurs in the vehicle, an accelerator pedal operation detecting unit that detects an operation on the accelerator pedal and transmits an accelerator pedal operation signal; When the accelerator pedal operation signal is transmitted from the accelerator pedal operation detection unit after the brake pressure is increased by the brake pressure increase unit, the brake pressure increase is stopped so that the brake pressure increase by the brake pressure increase unit is stopped. In the vehicle braking control device including a pressure stop unit, the brake pressure increase stop unit detects a brake pressure increased by the brake pressure increase unit when detecting an abnormality in the accelerator pedal operation signal. After the reduction for a predetermined time of 1, the brake pressure increase by the brake pressure increase unit is stopped.

  In the present invention, the automatic brake is operated by the brake pressure increasing section when the collision occurs, and the brake pressure is increased more than before the collision. If an abnormality occurs in the accelerator pedal operation signal, the brake pressure increased by the automatic brake operation is temporarily reduced, and then the automatic brake operation by the brake pressure increaser is stopped to further reduce the brake pressure. Let According to the present invention, when an abnormality occurs in the accelerator pedal operation signal, the operation of the automatic brake is forcibly stopped regardless of whether or not the accelerator pedal is operated, so that the vehicle can be accelerated at an early stage. In addition, even if the operation of the automatic brake is stopped, the brake operation using the brake pedal can be performed. For this reason, after the automatic brake is stopped, the driver can perform a brake operation as necessary to generate a brake pressure.

  In the present invention, the brake pressure increase stop unit may increase the brake pressure increased by the brake pressure increase unit during a second predetermined time when an abnormality occurs in the accelerator pedal operation signal. The brake pressure increased by the brake pressure increasing unit may be stopped after the brake pressure increased by the brake pressure increasing unit is decreased for the first predetermined time. . According to the present invention, the brake pressure increased during the collision is maintained until the second predetermined time has elapsed. For this reason, the braking distance can be shortened.

  According to the present invention, when an abnormality occurs in the accelerator pedal operation signal, the operation of the automatic brake is forcibly stopped regardless of whether or not the accelerator pedal is operated, so that the vehicle can be accelerated at an early stage.

FIG. 1 is a block diagram of a vehicle braking control apparatus according to an embodiment of the present invention. FIG. 2 is a characteristic diagram showing a target value of the maximum deceleration required for each vehicle speed. FIG. 3 is a flowchart for explaining the operation of the vehicle braking control device.

  Hereinafter, preferred embodiments of a vehicle braking control device according to the present invention will be described in detail with reference to the accompanying drawings.

[Configuration of Vehicle Braking Control Device 10]
The configuration of the vehicle braking control device 10 according to the present invention will be described with reference to the block diagram shown in FIG. The vehicle braking control device 10 includes various control units that include an ECU (electronic control unit). As is well known, the ECU is a computer including a microcomputer, a CPU (Central Processing Unit), a ROM (including EEPROM) as a memory, a RAM (Random Access Memory), other A / D converters, D / A converter and other input / output devices, a timer as a timekeeping unit, etc., and various function realization units (function realization means) such as a control unit when the CPU reads and executes a program recorded in the ROM , Functions as a calculation unit and a processing unit. These functions can also be realized by hardware. Further, the ECU can be integrated into one, and can be further divided.

  In the present embodiment, the ECU controls the overall control unit 12 including the airbag control unit 14, the travel safety control unit 16, and the abnormality detection unit 18, and the hydraulic control unit 20 and the engine control unit 24 connected to the overall control unit 12. And. The overall control unit 12 includes a timer 26 as a timer unit (timer). The overall control unit 12 controls the overall operation of the vehicle braking control device 10.

  The overall control unit 12 receives various sensor signals. In the present embodiment, the overall control unit 12 receives various sensor signals transmitted from the collision detection sensor 28, the G sensor 30, the vehicle speed sensor 32, the brake pedal operation amount sensor 42, and the accelerator pedal operation amount sensor 46.

The collision detection sensor 28 is, for example, a pressure sensor, and is provided at a plurality of locations of the vehicle so that a collision occurring around the vehicle can be detected. For example, a right front collision detection sensor and a left front collision detection sensor are provided on the left and right of the front frame of the vehicle, and a right side collision detection sensor and a left side collision detection sensor are provided on the left and right of the center frame of the vehicle. A right rear collision detection sensor and a left rear collision detection sensor are provided on the left and right of the left side. Collision detection sensor 28, to the general control unit 12 transmits a pressure signal S _P indicative of the pressure P generated in the frame.

The G sensor 30 detects an acceleration “a” in three orthogonal directions (vehicle length direction, vehicle width direction, vehicle height direction) of the vehicle, and is provided at the center of gravity position of the vehicle. G sensor 30, to the general control unit 12, and transmits an acceleration signal S _a indicating the acceleration a of the vehicle in the three axial directions.

The vehicle speed sensor 32 detects the vehicle speed V. For example, each wheel 62 is provided with a wheel speed sensor (not shown), and the vehicle speed sensor 32 uses the average value of the wheel speeds detected by each wheel speed sensor as the vehicle speed V. Vehicle speed sensor 32, to the general control unit 12, and transmits the vehicle speed signal S _V indicating the vehicle speed V.

Brake pedal operation amount sensor 42 is for detecting a brake pedal operation amount θb of the brake pedal 40, relative to the overall control unit 12, a brake pedal operation signal S.theta _b indicating the brake pedal operation amount θb of the brake pedal 40 Send.

Accelerator pedal operation amount sensor 46, which detects an accelerator pedal operation amount θa of the accelerator pedal 44, relative to the overall control unit 12, the accelerator pedal operation signal S.theta _a showing the accelerator pedal operation amount θa the accelerator pedal 44 Send.

The airbag control unit 14 included in the overall control unit 12 determines whether a collision has occurred in the vehicle based on the pressure signal S _P transmitted from the collision detection sensor 28 and the acceleration signal S _a transmitted from the G sensor 30. Judging. If it is determined that a collision has occurred, an airbag deployment signal S _ab that deploys the airbag 52 corresponding to the location where the collision has occurred is transmitted to the inflator 50. The inflator 50 operates in response to receiving the airbag deployment signal S _ab to deploy the airbag 52.

  The traveling safety control unit 16 provided in the overall control unit 12 transmits control signals to the hydraulic control unit 20 and the engine control unit 24 to control vehicle operations related to safety. For example, when the posture / behavior of the vehicle is disturbed, control is performed to improve the directional stability by preventing the vehicle from skidding. A vehicle posture stabilization system that improves the directional stability is known as a technology related to, for example, a VSA (Vehicle Stability Assist) system.

The traveling safety control unit 16 manages automatic brake control from operation to stop. The traveling safety control unit 16 performs automatic brake control via the hydraulic pressure control unit 20 when a collision that deploys the airbag 52 occurs, for example, when an airbag deployment signal _Sab is received. The automatic brake control is performed based on the VG relationship 22 shown in FIG. The traveling safety control unit 16 controls the brake pressure so as to obtain the maximum deceleration G corresponding to the vehicle speed V based on the relationship 22 shown in FIG.

Furthermore, when the accelerator pedal operation amount sensor 46 detects the operation of the accelerator pedal 44 while the automatic brake control is being performed, the traveling safety control unit 16 stops the automatic brake control immediately or after a predetermined time has elapsed. . Driving safety control unit 16, when the accelerator pedal operation amount θa indicating the accelerator pedal operation signal S.theta _a transmitted from the accelerator pedal operation amount sensor 46 is equal to or greater than the threshold value, it is determined that the required stop automatic brake control.

If there is an abnormality in the accelerator pedal operation signal S.theta _a is, there is a possibility that the operation of the accelerator pedal 44 is not transmitted to the driving safety control unit 16. Therefore, driving safety control unit 16, in response to the abnormality detection unit 18 by the accelerator pedal operation signal S.theta _a abnormality detection result performed to determine the automatic brake control stop or continue. Details of the processing will be described later with reference to FIG.

The abnormality detection unit 18 provided in the overall control unit 12 has an abnormality in the brake pedal operation signal Sθ _b transmitted from the brake pedal operation amount sensor 42 and the accelerator pedal operation signal Sθ _a transmitted from the accelerator pedal operation amount sensor 46. To detect. If a detection abnormality occurs in the brake pedal operation amount sensor 42 or the accelerator pedal operation amount sensor 46 due to the collision, the brake pedal operation amount θb and the accelerator pedal operation amount θa become abnormal values. The abnormality detection unit 18 determines whether the brake pedal operation amount θb and the accelerator pedal operation amount θa are normal values or abnormal values. Further, when a communication abnormality occurs due to a collision, an abnormality occurs in the signals Sθ _b and Sθ _a transmitted from the brake pedal operation amount sensor 42 and the accelerator pedal operation amount sensor 46. The abnormality detection unit 18 detects abnormality of each signal Sθ _b and Sθ _{a by a} general data communication error detection method, for example, inspection using a checksum. The abnormality detection unit 18 outputs the abnormality detection result to the traveling safety control unit 16.

The hydraulic control unit 20 generates brake pressure that acts on the brake actuator 60 under the control of the traveling safety control unit 16. If a collision has not occurred, the hydraulic control unit 20 generates a brake pressure corresponding to the brake pedal operation signal S.theta _b transmitted from the brake pedal operation amount sensor 42. Further, when a collision occurs, the hydraulic control unit 20 generates a brake pressure at which the maximum deceleration G required by the traveling safety control unit 16 is obtained.

  The brake actuator 60 brakes each wheel 62 by generating a braking force according to the brake pressure. The brake actuator 60 includes, for example, a brake caliper, a brake rotor, and the like. The brake caliper incorporates a brake piston and brake pads. When the brake pressure acts on the brake piston, the brake piston presses the brake pad against the brake rotor. At this time, a frictional force corresponding to the brake pressure is generated in the brake rotor, and the braking force of the wheel 62 is obtained.

The engine control unit 24, in the under the control of the travel safety control unit 16 controls the opening degree of the throttle valve (THV) 66 according to the accelerator pedal operation signal S.theta _a transmitted from the accelerator pedal operation amount sensor 46 The number of revolutions of the engine 64 is controlled. The driving force of the engine 64 is transmitted to the wheel 62 via a transmission (T / M) 68 or the like.

[Operation of Vehicle Braking Control Device 10]
Next, the operation of the vehicle braking control device 10 will be described with reference to the flowchart shown in FIG. Note that the execution subject of the program according to the flowchart is the overall control unit 12.

In step S1, the overall control unit 12 receives the pressure signal S _P transmitted from the collision detection sensor 28, the acceleration signal S _a transmitted from the G sensor 30, and the vehicle speed signal S _V transmitted from the vehicle speed sensor 32. The brake pedal operation signal Sθ _b transmitted from the brake pedal operation amount sensor 42 and the accelerator pedal operation signal Sθ _a transmitted from the accelerator pedal operation amount sensor 46 are received, pressure P, acceleration a, vehicle speed V, brake pedal Each data of the operation amount θb and the accelerator pedal operation amount θa is acquired. Each data is taken in continuously every predetermined time, for example, every very short time on the order of ms (milliseconds), while executing each process of the flowchart shown in FIG.

Next, in step S2, the traveling safety control unit 16 determines whether or not the airbag 52 is deployed. When a collision occurs, the airbag control unit 14 determines whether or not to deploy the airbag 52 based on the pressure signal S _P transmitted from the collision detection sensor 28 and the acceleration signal S _a transmitted from the G sensor 30. To do. If a collision has no or minor collision occurs occurs, the pressure P indicated by the pressure signal S _P is less than the predetermined value, and / or an acceleration (deceleration) represented by the acceleration signal S _a a certain Is less than the value. In such a case, the airbag control unit 14 determines that the airbag 52 is not required to be deployed, and does not transmit the airbag deployment signal S _ab to the inflator 50. For this reason, the inflator 50 does not operate and the airbag 52 does not deploy. At this time, the traveling safety control unit 16 determines that the airbag 52 is not deployed (step S2: NO), and does not perform the automatic brake control according to the present embodiment.

If severe collision occurs, the pressure P indicated by the pressure signal S _P is not less than a predetermined value, and the acceleration (deceleration) represented by the acceleration signal S _a a is a predetermined value or more. In such a case, the airbag control unit 14 determines that the airbag 52 needs to be deployed, and transmits an airbag deployment signal S _ab to the inflator 50. Then, the inflator 50 operates and the airbag 52 is deployed. The traveling safety control unit 16 determines that the airbag 52 has been deployed by the generation of the airbag deployment signal _Sab (step S2: YES), and proceeds to step S3.

In step S3, the traveling safety control unit 16 activates the automatic brake. That is, driving safety control unit 16 sends the braking signal S _B to the hydraulic control unit 20 to start the automatic brake control. The brake pressure generated by the hydraulic control unit 20 is determined based on the curve A of the relationship 22 shown in FIG. At this time, the maximum deceleration G corresponding to the vehicle speed V is obtained from the curve A, and the brake pressure at which the maximum deceleration G is obtained is determined. Note that the timer 26 starts timing simultaneously with the operation of the automatic brake in step S3.

A temporary detection abnormality occurs in the brake pedal operation amount sensor 42 and the accelerator pedal operation amount sensor 46 due to the collision, or a communication abnormality temporarily occurs in the communication line between the sensors 42 and 46 and the overall control unit 12. When this occurs, an abnormality occurs in the values of the operation signals Sθ _b and Sθ _a and / or the pedal operation amounts θb and θa. In step S4, the abnormality detecting unit 18 determines whether there is an abnormality in the value of the accelerator pedal operation signal S.theta _a and / or the accelerator pedal operation amount θa is transmitted from the accelerator pedal operation amount sensor 46.

If there is an abnormality in the accelerator pedal operation signal S.theta _a (step S4: YES), the process proceeds to step S5. In step S5, the traveling safety control unit 16 refers to the timer 26 and determines whether a predetermined time (second predetermined time), for example, 1 second has elapsed since the automatic brake was activated. Until the predetermined time has elapsed (step S5: NO), the process proceeds to step S8. At this time, the traveling safety control unit 16 continues the automatic braking with the brake pressure increased (generated) at the time of the collision. When the predetermined time has elapsed (step S5: YES), the process proceeds to step S6.

In step S6, the travel safety control unit 16 performs automatic brake control by reducing the target value of the maximum deceleration G corresponding to the vehicle speed V by 40%. At this time, the brake pressure is reduced by 40%. Simultaneously with the reduction of the brake pressure, the timer 26 starts counting again. The traveling safety control unit 16 continues the brake pressure control reduced by 40% for a predetermined time (first predetermined time), for example, 1 second. Thereafter, the process proceeds to step S7, and the traveling safety control unit 16 stops the automatic brake. That is, driving safety control unit 16 sends a stop signal S _END to the hydraulic control unit 20 via the hydraulic control unit 20, and ends the automatic brake control. Since the brake pressure increased here is lost (becomes 0), acceleration can be performed by operating the accelerator pedal 44.

On the other hand, when there is no abnormality in the accelerator pedal operation signal S.theta _a (step S4: NO), the process proceeds to step S9. In step S9, the abnormality detecting unit 18 determines whether there is an abnormality in the value of the brake pedal operation signal S.theta _b and / or the brake pedal operation amount θb is transmitted from the brake pedal operation amount sensor 42.

If something is wrong with the brake pedal operation signal S.theta _b (step S9: YES), the process proceeds to step S10. In step S10, the travel safety control unit 16 continues the brake pressure increased (generated) at the time of the collision for a predetermined time, for example, 1 second from the automatic brake operation. Thereafter, the process proceeds to step S7, and the traveling safety control unit 16 stops the automatic brake. That is, driving safety control unit 16 sends a stop signal S _END to the hydraulic control unit 20, and ends the automatic brake control. Since the brake pressure increased here is lost (becomes 0), acceleration can be performed by operating the accelerator pedal 44.

If there is no abnormality in the brake pedal operation signal S.theta _b (step S9: NO), the process proceeds to step S11. At step S11, driving safety control unit 16, a predetermined time and the vehicle speed V vehicle speed V indicated by the speed signal S _V transmitted from the vehicle speed sensor 32 becomes 0 or not equal to zero or less, for example 1.5 seconds Determine if it has passed.

  When the vehicle speed V is not 0 or less or the predetermined time has not elapsed after the vehicle speed V becomes 0 or less (step S9: NO), the process proceeds to step S12. At this time, the traveling safety control unit 16 continues the automatic braking with the brake pressure increased (generated) at the time of the collision.

On the other hand, when the vehicle speed V becomes 0 or less and a predetermined time has elapsed thereafter (step S11: YES), the process proceeds to step S7, and the traveling safety control unit 16 stops the automatic brake. That is, driving safety control unit 16 sends a stop signal S _END to the hydraulic control unit 20, and ends the automatic brake control. Since the brake pressure increased here is lost (becomes 0), acceleration can be performed by operating the accelerator pedal 44.

[Another embodiment]
In the process shown in FIG. 3, the processes shown in steps S5 and S8 may be omitted. In this case, at step S4, if it is determined that there is an abnormality in the accelerator pedal operation signal S.theta _a, the process proceeds to step S6, the braking pressure is 40% controlled by automatic brake reduced without waiting for the elapse of the predetermined time period Is done.

[Summary of Embodiment]
As described above, in the vehicle braking control apparatus 10 according to the present embodiment, when a collision occurs in the vehicle, the brake pressure increasing unit (travel safety control unit 16, hydraulic control) increases the brake pressure more than before the collision. unit 20, a brake actuator 60), the accelerator pedal operation detection unit that transmits the accelerator pedal operation signal S.theta _a detects the operation on the accelerator pedal 44 (the accelerator pedal operation amount sensor 46), the brake pressure by the brake-pressure pressure section brake pressure increasing stopping unit stopping pressure increase of the brake pressure by the brake -pressure pressure section when the increasing depressurizing accelerator pedal operation signal from the accelerator pedal operation detection portion S.theta _a is sent in (running safety control unit 16, the hydraulic A control unit 20 and a brake actuator 60). The brake pressure increasing stop, when abnormality in the accelerator pedal operation signal S.theta _a occurs: (step S4 YES), while the brake pressure was boosted by the brake pressure increase pressure section of the first predetermined time The brake pressure is increased (step S6), and then the brake pressure increase by the brake pressure increaser is stopped (step S7).

In the present embodiment, when a collision occurs, the brake is increased by a brake pressure increasing unit (travel safety control unit 16, hydraulic control unit 20, brake actuator 60) to increase the brake pressure before the collision. When an abnormality occurs in the accelerator pedal operation signal S.theta _a temporarily decrease the brake pressure was boosted by the operation of the automatic brake, after which the stops the operation of the automatic brake by the brake pressure increasing pressure part brake pressure Further decrease. According to this embodiment, the acceleration when the abnormality occurs in the accelerator pedal operation signal S.theta _a, regardless of the presence or absence of operation of the accelerator pedal 44, since the operation of the automatic brake is forcibly stopped, the vehicle early Is possible. Even if the automatic brake operation is stopped, the brake operation using the brake pedal 40 is possible. For this reason, after the automatic brake is stopped, the driver can perform a brake operation as necessary to generate a brake pressure.

Further, in the case in the present embodiment, the brake pressure increasing stop (running safety control unit 16, the hydraulic control unit 20, the brake actuator 60), an abnormality occurs in the accelerator pedal operation signal S.theta _a brake pressure increasing The brake pressure increased by the units (travel safety control unit 16, hydraulic control unit 20, brake actuator 60) is maintained for a second predetermined time (step S5, step S8), and thereafter the brake pressure increase unit The increased brake pressure is decreased for a first predetermined time (step S6), and then the brake pressure increase by the brake pressure increasing unit is stopped (step S7).

  According to the present embodiment, the brake pressure increased during the collision is maintained until the second predetermined time elapses. For this reason, the braking distance can be shortened.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Vehicle braking control apparatus 12 ... General control unit 14 ... Airbag control unit 16 ... Travel safety control unit 18 ... Abnormality detection unit 20 ... Hydraulic control unit 28 ... Collision detection sensor 30 ... G sensor 44 ... Accelerator pedal 46 ... Accelerator pedal Operation amount sensor 60 ... brake actuator 62 ... wheel

Claims (2)

A brake pressure increasing section for increasing the brake pressure before the collision when a collision occurs in the vehicle;
An accelerator pedal operation detector that detects an operation on the accelerator pedal and transmits an accelerator pedal operation signal;
Brake pressure increase for stopping the brake pressure increase by the brake pressure increaser when the accelerator pedal operation signal is transmitted from the accelerator pedal operation detection unit after the brake pressure increase by the brake pressure increaser In a vehicle braking control device comprising a stop unit,
The brake pressure increase stop unit continues the brake pressure control for reducing the brake pressure increased by the brake pressure increase unit for a first predetermined time when detecting an abnormality in the accelerator pedal operation signal. Then, the vehicle brake control device stops brake pressure increase by the brake pressure increase section. The vehicle braking control device according to claim 1,
The brake pressure increase stop unit maintains the brake pressure increased by the brake pressure increase unit for a second predetermined time when an abnormality occurs in the accelerator pedal operation signal, and thereafter The brake pressure increase by the brake pressure increasing portion is stopped after the brake pressure control for reducing the brake pressure increased by the pressure increasing portion is continued for the first predetermined time. Braking control device.

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