JPH08150910A - Control device of automatic brake device - Google Patents

Abstract

PURPOSE: To surely prevent increase in power consumption and burning of a solenoid valve at the time of automatic brake stopping during long time in a system for preventing contact by an automatic brake. CONSTITUTION: The possibility of contact of a vehicle with its opposite object is decided according to signals from an automatic brake select switch 52, a CCD camera 50, a car speed sensor 51, and a brake switch 53. The control device comprises an automatic brake control means C1 for outputting signals of pressurization, holding and decompression of brake pressure to the respective decompression solenoid valves 30, 40, and pressurization solenoid valves 32, 42 to operate an automatic brake if brake operation is not conducted though there is the possibility of contact, and warning output means C2 for giving a warning by a warning device 70 after the lapse of designated time when stopping in the automatic brake state is decided according to an automatic brake operating signal and a car speed signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an automatic braking device that automatically brakes a vehicle such as an automobile, and more particularly, to prevent burning of a solenoid valve when the automatic braking device is stopped for a long time. Regarding measures.

[0002]

2. Description of the Related Art In recent years, as a measure to dramatically improve the safety of a vehicle, a technique for avoiding a collision, that is, an operation system is automatically controlled to a safety side as compared with a technique for reducing a collision damage such as an airbag. Comprehensive driving support system (Active Drive Assist S
The system (hereinafter referred to as ADA system) has been developed. This ADA system is a control unit that three-dimensionally recognizes the road environment, the external environment of other vehicles, road obstacles, etc. by CCD cameras mounted in front of and behind the vehicle.
It is equipped with various devices that automatically and properly operate the operation system such as the brake, throttle, and steering, and is configured to be capable of autonomous traveling. As a function of the ADA system, in the case of an unsafe driving operation that is likely to occur during on-the-spot driving or drowsy driving, a safe inter-vehicle distance is secured and the driver is replaced so as to prevent vehicle contact. An automatic driving function, which substitutes for driving operation, is being considered.

In such an ADA system, there is an automatic braking device as a means for preventing contact while the vehicle is running and maintaining the stop while the vehicle is stopped. The specific configuration of this automatic braking device has already been described by the applicant of the present invention as follows. Is proposed. Here, it is premised that the driver assists the automatic brake only when the driver needs it. Therefore, the driver is provided with an automatic brake selection switch for selecting whether the automatic brake is operated or not. Further, an automatic brake hydraulic unit having a brake system pressurizing source is provided, and an ON-OFF type of pipe is provided in the conduit between the pressurizing source and the two diagonal P system and S system brake conduits. A pressurizing solenoid valve and a depressurizing solenoid valve are provided as means for electronically controlling the brake pressure. In this case, the pressurizing solenoid valve is set to normally closed and the depressurizing solenoid valve is set to normally open. Normally, both solenoid valves are opened and closed without power supply, and the brake can be arbitrarily braked by the foot brake operation by the brake pedal. There is.

When the possibility of contact is predicted while approaching a preceding vehicle while the vehicle is running with the automatic brake selection switch turned on, an ON / OFF signal or a predetermined duty ratio signal is sent to the pressurizing solenoid valve and the depressurizing solenoid valve. To control the brake pressure of the wheel cylinder to automatically pressurize, hold, and depressurize it by outputting the output to the vehicle to ensure contact with the preceding vehicle. The automatic brake operates to prevent it. Therefore, when temporarily decelerating the preceding vehicle while the vehicle is traveling, the solenoid valve control and energization time are several seconds as in the ABS and TCS systems.
No trouble will occur.

By the way, in the case of an automatic brake device, the vehicle may be stopped due to the state of automatic braking in relation to the preceding vehicle, and at this time, the pressure reducing solenoid valve and the pressure solenoid valve are continuously operated to stop the vehicle. The vehicle contact with the vehicle while stopped is prevented. However, when the driver stops for a long time without being aware of it due to traffic congestion or the like in the state of automatic braking, the solenoid valve or the like is continuously energized for a long time, which may cause troubles such as increased power consumption and burnout of the solenoid. Therefore, when the vehicle is stopped in the state of automatic braking, it is required to take measures to protect the solenoid valve and the like.

Conventionally, for the control when the automatic brake is stopped, there is, for example, the prior art of Japanese Patent Laid-Open No. 64-60457. In this prior art, as a measure for facilitating the start of a slope on an uphill road, an electromagnetic check valve for braking is provided in the brake pipe line, and when a stop on a slope is judged by various sensor signals, the brake pressure is applied to the wheel by the check valve. When the brake is retained in the cylinder to hold the braking force and it is judged that the vehicle has started, the check valve is controlled to release the brake, and while the braking force is being held by the check valve, the holding pressure decreases due to changes in parts over time. It is shown that when the vehicle starts to move and the vehicle speed sensor detects it, an alarm is issued to prompt the driver to increase the brake pedal.

Further, in the prior art of Japanese Patent Laid-Open No. 64-60460, when the braking force holding time exceeds a set value in the same technical field, an alarm is issued in consideration of the possibility of the holding pressure lowering. It is also shown that the driver is prompted to press the brake pedal more to prevent the vehicle from moving.

[0008]

By the way, in each of the above-described prior arts, the brake pressure is controlled so as to be simply held or released when the vehicle is stopped as a measure for starting a slope, and therefore, the present invention is not limited to the above. In addition, it cannot be applied to feedback control such that the brake pressure is increased, maintained, or reduced as a measure to prevent a collision during traveling. Further, since the purpose of the alarm is to prevent the vehicle from moving due to a decrease in holding pressure on a slope, it is not possible to prevent the solenoid valve from burning.

In view of the above points, an object of the present invention is to reliably prevent an increase in power consumption and a burnout of a solenoid valve when the automatic brake is stopped for a long time in a system for preventing contact by an automatic brake. To do.

[0010]

To achieve this object, a control device for an automatic brake device according to claim 1 of the present invention, as shown in FIG. 1, brakes in response to an operation of a brake pedal 13 of a vehicle. Master cylinder 1 that generates pressure
4 and the wheel cylinders 17 and 19 for braking the wheels in accordance with the brake pressure, pressure reducing solenoid valves 30 and 40 are provided in the brake pipes 16 and 18, and the brakes on the downstream side of the pressure reducing solenoid valves 30 and 40 are provided. An automatic brake hydraulic unit in which the pipelines 26 and 44 from the pressure source 34 communicate with the pipelines 16 and 18 via the pressurizing solenoid valves 32 and 42, and an automatic brake selection that selects activation / deactivation of the automatic brake. The pressure reducing solenoid valve 3 is based on signals from a switch 52, a CCD camera 50 that monitors the front of the vehicle, a vehicle speed sensor 51 that detects the speed of the vehicle, and a brake switch 53 that detects whether or not the brake pedal 13 is operated.
0 and 40 and an automatic brake control unit that controls the operation of the pressurizing solenoid valves 32 and 42, the automatic brake control unit includes the automatic brake selection switch 52, the CCD camera 50, and the vehicle speed sensor 51. Based on each signal from the brake switch 53, the possibility of contact with an object facing the host vehicle is judged, and the brake pedal 13 is contacted despite the possibility of contact.
When there is no operation, the automatic brake control means C1 for operating the automatic brake by outputting the signals for pressurizing, holding and depressurizing the brake pressure to the pressure reducing solenoid valves 30 and 40 and the pressure increasing solenoid valves 32 and 42, respectively. And, when it is determined that the vehicle is stopped in the automatic brake operating state based on the automatic brake operating signal from the automatic brake control means C1 and the vehicle speed signal from the vehicle speed sensor, an alarm output for issuing an alarm by an alarm device 70 after a predetermined time has elapsed And means C2.

Further, as shown in FIG. 2, the control device for an automatic brake device according to a second aspect of the present invention includes a master cylinder 14 for generating a brake pressure in response to an operation of a brake pedal 13 of a vehicle and a wheel in accordance with the brake pressure. A pressure reducing solenoid valve 30 is provided in the P system brake pipeline 16 of two diagonal systems that communicates with the wheel cylinders 17 and 19 that brake the vehicle.
Another pressure reducing solenoid valve 40 is provided in the system brake pipe line 18, and one pipe line 26 from the pressure source 34 is added to the P system brake pipe line 16 downstream of the pressure reducing solenoid valve 30. The other line 44 from the pressurizing source 34 is connected to the pressurizing solenoid valve 4 on the downstream side of the pressure reducing solenoid valve 40 in the S-system brake pipe 18 through the pressure solenoid valve 32.
2, an automatic brake hydraulic unit communicating via 2, an automatic brake selection switch 52 for selecting the operation / non-operation of the automatic brake, a CCD camera 50 for monitoring the front of the vehicle,
Based on signals from a vehicle speed sensor 51 that detects the speed of the vehicle and a brake switch 53 that detects whether or not the brake pedal 13 has been operated, the pressure reducing solenoid valves 30 and 40 described above.
And an automatic brake control unit for controlling the operation of the pressurizing solenoid valves 32, 42, the automatic brake control unit includes the automatic brake selection switch 52, the CCD camera 50, the vehicle speed sensor 51, and the brake. Based on each signal from the switch 53,
The possibility of contact between the host vehicle and the opposite object is determined, and if the brake pedal 13 is not operated in spite of the possibility of contact, the above-mentioned signals for pressurizing, holding and depressurizing the brake pressure are given as above. P and S system pressure reducing solenoid valves 30, 40 and P
Output to each pressurizing solenoid valve 32, 42
Automatic braking control means for simultaneously activating the automatic braking of the system and the S system, and stopping the vehicle in the automatic braking operating state based on the automatic braking operation signal from the automatic braking control means C1 and the vehicle speed signal from the vehicle speed sensor 51. If judged, one of the P system and S system is pressurized and held, and the other is released, and a vehicle stop holding control pattern is set.
Retaining and releasing signals are sent to the P system pressure reducing solenoid valve 30 and the pressurizing solenoid valve 32, and the S system pressure reducing solenoid valve 40.
And the stop solenoid control means C3 for alternately outputting to the pressurizing solenoid valve 42 at predetermined time intervals to alternately operate the P system and S system automatic brakes.

Therefore, in the control device for the automatic brake device according to the first aspect, when the automatic brake selection switch 52 is turned on while the vehicle is running, the automatic brake control means C1 receives the signals from the CCD camera 50 and the vehicle speed sensor 51. For example, the possibility of contact between the host vehicle and the preceding vehicle is determined. If there is no possibility of contact, the pressure solenoid valves 32 and 42 are closed and the pressure reducing solenoid valve 3 is deenergized.
0 and 40 are opened, and the foot brake by the brake pedal can be operated. Therefore, when the brake pedal 13 is operated, the master cylinder 14 generates a brake pressure, and the wheel cylinders 17 and 19 operate to decelerate and brake the vehicle arbitrarily.

On the other hand, if the brake pedal 13 is not operated despite the possibility that the host vehicle may come into contact with the preceding vehicle, the pressure reducing solenoid valves 30 and 40 are closed and the pressure applying solenoid valves 32 and 42 are opened. The pressure source 34 applies pressure to generate a brake pressure. In addition, the pressure reducing solenoid valve 30,
The brake pressure is reduced by opening 40 and closing the pressure solenoid valves 32, 42, and further reducing pressure solenoid valves 30, 4
0 and the pressurizing solenoid valves 32 and 42 are closed to control the brake pressure to operate the automatic brake, whereby the inter-vehicle distance to the preceding vehicle is secured and contact with the preceding vehicle is prevented.

At this time, when the alarm output means C2 determines that the vehicle is stopped in the automatic brake operating state, it monitors the energization time of the solenoid valve and the like, and the alarm device 70 issues an alarm after a lapse of a predetermined time. If the driver notices this and operates the brake pedal, the automatic brake is released and the depressurizing solenoid valve and the pressurizing solenoid valve stop operating due to energization. Is prevented.

On the other hand, in the control device for the automatic brake device according to the second aspect, when the automatic brake selection switch 52 is turned on while the vehicle is running, the automatic brake control means C1 receives signals from the CCD camera 50 and the vehicle speed sensor 51. When the possibility of contact between the host vehicle and the preceding vehicle is determined, and when there is no possibility of contact, for example, the P-system and S-system pressurizing solenoid valves 32 and 42 of the diagonal two systems are closed while the current is not energized. , P-system and S-system pressure reducing solenoid valves 30 and 40 are opened, and the foot brake by the brake pedal becomes operable. Therefore, by operating the brake pedal 13,
The master cylinder 14 generates brake pressure, and P system and S
The vehicle is arbitrarily decelerated and braked by simultaneously operating the wheel cylinders 17 and 19 of the system.

On the other hand, when the brake pedal 13 is not operated although the own vehicle may come into contact with the preceding vehicle, the pressure reducing solenoid valves 30 and 40 of the P system and the S system are closed and the P system and the S system are closed. The pressurizing solenoid valves 32 and 42 of the system are opened, and the pressurizing source 34 pressurizes so as to generate a brake pressure. Also, open the P and S pressure reducing solenoid valves 30 and 40 to
The brake pressure is reduced by closing the pressure solenoid valves 32, 42 of the system and the S system, and the pressure reduction solenoid valves 30, 40 and the pressure solenoid valves 32, 42 of the P system and the S system are closed to maintain the brake pressure. The automatic braking of the P system and the S system is simultaneously actuated so that the inter-vehicle distance with respect to the preceding vehicle is secured and contact with the preceding vehicle is prevented in advance.

At this time, when the vehicle stop control means C3 judges that the vehicle is stopped in the automatic brake operating state, the brake pressure is increased and maintained by the pressure reducing solenoid valve 30 and the pressure increasing solenoid valve 32 of the P system, for example, according to the set control pattern. Thus, the vehicle stop state is maintained, and the S-system pressure reducing solenoid valve 40 and the pressurizing solenoid valve 42 are de-energized to release the automatic braking. Next, the S system pressure reducing solenoid valve 4
0 and the pressurizing solenoid valve 42 are controlled to pressurize and hold the brake pressure to hold the vehicle in a stopped state, and the depressurizing solenoid valve 30 and pressurizing solenoid valve 32 of the P system are de-energized to release the automatic brake. . By repeating this alternately every predetermined time, the continuous energization time of the pressure reducing solenoid valve and the pressure applying solenoid valve is shortened, and the coil burnout or the like is prevented.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. An outline of the drive system and the brake system of the vehicle will be described with reference to FIG. First, a vehicle has left and right front wheels 1L, 1R and rear wheels 2L, 2R. As a drive unit A, an engine 3 passes through a clutch 4, a transmission 5, a propeller shaft 6, a differential unit 7, and an axle 8, for example, left and right. Rear wheel 2
It is configured to transmit to L and 2R. The throttle valve 10 of the engine 3 is provided with an actuator 11, and the throttle control unit 12 controls the throttle during automatic braking and other control such as ABS and TCS.

The brake device B includes a master cylinder 14 that generates a brake pressure by operating a brake pedal 13.
As a diagonal two-system brake pipe 15, a P-system brake conduit 16 connects to the wheel cylinder 17 of the right front wheel 1R and the left rear wheel 2L, and an S-system brake conduit 18 forms the left front wheel 1L.
And the wheel cylinder 19 of the right rear wheel 2R. An automatic brake hydraulic unit 21 of the automatic brake device 20 is provided in the middle of the P system and S system brake pipes 16 and 18 so that the automatic brake operation is performed by a signal from the automatic brake control unit 60. When the ABS device is installed, the ABS hydraulic unit is connected in series to the downstream side of the automatic brake hydraulic unit, and it is possible to prevent wheel lock during automatic brake operation.

The automatic brake hydraulic unit 21 will be described with reference to FIG. Brake piping 15 with two diagonal lines
The P-type brake pipeline 16 will be described. The P-type brake pipeline 16 is provided with a pressure reducing solenoid valve 30 and a relief valve 31. Further, as a pressurizing source 34, a pipe line 23 from the oil reservoir 22 of the master cylinder 14 communicates with an oil pump 24 driven by a motor 25. The discharge side pipeline 26 of the oil pump 24 communicates with a relief valve 28 via a check valve 27, and further communicates with an accumulator 29 so that pressure can be accumulated. Further, the pipe line 26 has a pressurizing solenoid valve 32 and communicates with the P-system brake pipe line 16 downstream of the pressure reducing solenoid valve 30.

The pipe lines 16 and 26 have pedal pressure, brake pressure,
Oil pressure sensor 36, 33, 3 for detecting accumulator pressure
7, and a pressure switch 35 is provided in the pipe line 26. The pressure switch 35 sets the motor 25 at the set lower limit pressure.
Is driven and the motor 25 is stopped at the set upper limit pressure to operate the oil pump 24, and a high pressure accumulator pressure is constantly accumulated in the accumulator 29. It is possible to pressurize with high response by the high pressure accumulator pressure.

On the other hand, S of the brake piping 15 of the diagonal two system
Similarly, a pressure reducing solenoid valve 40 and a relief valve 41 are provided in the system brake pipe line 18, and a pipe line 44 branched from the pump side pipe line 26 has a pressurizing solenoid valve 42. It communicates with the downstream of the pressure reducing solenoid valve 40. A hydraulic pressure sensor 43 for detecting the brake pressure is also provided in the S-system brake pipe 18.

The depressurizing solenoid valves 30 and 40 are normally open, and are opened when the power is not supplied and are closed when the power is supplied. The pressurizing solenoid valves 32 and 42 are normally closed, and are closed by turning off the non-energized state and opened by turning on the energized state.

As a result, when the pressurizing solenoid valves 32 and 42 are closed in the OFF state and the depressurizing solenoid valves 30 and 40 are opened in the OFF state, the normal foot brake is possible. On the other hand, when the depressurizing solenoid valves 30 and 40 are turned on and closed, and the pressurizing solenoid valves 32 and 42 are turned on at a predetermined duty ratio at this time to change the valve opening, the brake pressure is increased by the accumulator pressure. And the pressure reducing solenoid valve 30,
40 is closed by ON, and the pressurizing solenoid valves 32, 42 are OF
When closed at F, brake pressure is contained and retained. Further, the pressurizing solenoid valves 32, 42 are turned off and closed, and at this time, the depressurizing solenoid valves 30, 40 are turned on at a predetermined duty ratio.
When FF is performed and the valve opening changes, the brake pressure is released and the brake pressure is controlled to decrease. The brake pressure can be appropriately feedback-controlled by the pressurization, holding, and depressurization to perform the automatic braking operation.

The overall functional blocks of the automatic brake control unit 60 will be described with reference to FIG. First, the CCD camera 50 is arranged in front of and behind the vehicle to recognize an object such as a road condition and a preceding vehicle facing the own vehicle, and obtains distance information thereof, a vehicle speed sensor 51 for detecting a vehicle speed V, an automatic brake selection switch 52, an actual vehicle. The hydraulic pressure sensors 33 and 43 for detecting the brake pressure Pb, the brake switch 53 for detecting the state of the foot brake operation, and the throttle opening sensor 54 for detecting the throttle opening θ. The signals of these sensors and switches are input to the automatic brake control unit 60 and electrically processed.

The automatic brake control unit 60 is a CCD
The camera 50, the signal from the automatic brake selection switch 52, and the approach prediction unit 61 to which the vehicle speed V is input are included. When the automatic brake selection switch 52 is ON, the CC
Based on the signal from the D camera 50, for example, the relative distance L between the host vehicle and the preceding vehicle and the relative speed Vs are calculated to determine the approaching state between the host vehicle and the preceding vehicle, and the possibility of contact is predicted. An approach warning signal is output to. Further, when the automatic brake selection switch 52 is OFF, or when there is no possibility of contact, the duty output section 67 causes the pressure reducing solenoid valves 30, 40 and the pressurizing solenoid valves 32,
An OFF signal is output to 42. The approach signal and the throttle opening θ are input to the throttle closing determination unit 62, and if the throttle opening θ is equal to or more than the set value at the time of contact prediction, the throttle closing signal is output to the throttle control unit 12.

The approach signal is input to the target acceleration setting unit 63 to set a negative target acceleration Gt for avoiding contact when predicting contact. The vehicle speed V is input to the actual acceleration calculating unit 64, and the vehicle speed V is differentiated to calculate the actual acceleration G. The negative target acceleration Gt and the actual acceleration G are input to the deviation calculator 65, and the deviation ΔG between the two is calculated by ΔG = Gt−G. The deviation ΔG and the actual acceleration G are input to the pressurization, holding, and depressurization determination unit 66, and the pressurization, holding, and depressurization are determined based on the preset control dead zone a, the deviation ΔG, and the sign of the actual acceleration G. To do. That is, if the absolute value of the deviation | ΔG | is within the control dead zone a, it is determined to hold. Absolute value of deviation |
When ΔG | is outside the control dead zone a and ΔG> 0, that is, Gt> G, the actual acceleration is negative and smaller than the target acceleration, so that the pressure reduction is determined. When ΔG <0, that is, when Gt <G and G <0, the actual acceleration is negative and larger than the target acceleration, so pressurization is determined, and when G> 0, before deceleration is determined.

These pressurization, pressure reduction, holding or deceleration determination signals, the brake switch 53 signal, the deviation ΔG, and the actual brake pressure Pb are input to the duty output section 67, and O
N, OFF, or converted into a duty signal and output. First, when the driver depresses the brake pedal 13 by a contact alarm or the like to operate the foot brake and the brake switch 53 is turned on, it is judged to avoid contact and the pressure reducing solenoid valves 30 and 40 and the pressurizing solenoid valves 32 and 42 are turned off. Output a signal. When the brake switch 53 is OFF, the target instruction pressure Pt is set according to the deviation ΔG, and the deviation ΔP between the target instruction pressure Pt and the brake pressure Pb is converted to a predetermined duty ratio D by PID control, for example.

In the case of pressurization, the pressure reducing solenoid valve 3
Output ON signal to 0, 40, pressurizing solenoid valve 32,
An ON signal of the duty ratio D is output to 42, and an ON signal of a predetermined duty ratio Di is output as an initial value to the pressurizing solenoid valves 32 and 42 before deceleration. In the case of depressurization, an OFF signal is output to the pressurizing solenoid valves 32 and 42, and the duty ratio D is output to the depressurizing solenoid valves 30 and 40.
The OFF signal of is output. Further, in the case of holding, an OFF signal is output to the pressurizing solenoid valves 32 and 42, and an ON signal is output to the depressurizing solenoid valves 30 and 40.

Next, a measure for preventing the solenoid valve from burning when the automatic brake is stopped for a long time will be described. First, when the automatic brake is to be stopped for a long time, an alarm is given to the driver and the operation of the foot brake or the parking brake is prompted to release the automatic brake. Also, the diagonal of the brake system 2
Although two sets of pressurizing / depressurizing solenoid valves 30 and 32, 40 and 42 are provided in the P system and S system Buki pipe lines 16 and 18, the braking force for keeping the vehicle stopped is small. Therefore, P system and S
Two sets of pressure increasing / decreasing solenoid valves 30 and 32, 40 and 42
By alternating the automatic brake operation with, the burden of energizing the solenoid valve can be reduced.

An embodiment for issuing an alarm will now be described. The duty output unit 67 has an alarm output unit 68 to which the signal of the automatic braking state and the vehicle speed V are input. When the automatic braking is in operation and the vehicle is stopped at V = 0, the timer 69 starts counting to monitor the energization time, and when a predetermined time elapses, an alarm is issued by the automatic brake warning lamp 70 as an alarm device.

Next, the automatic brake control will be described with reference to the flowchart of FIG. First, during engine operation, initialization is performed when the ignition switch is turned on in step S1. That is, in the brake system of FIG. 4, the pressurizing solenoid valves 32 and 42 are turned off and closed to disconnect the pressurizing source 34, and the depressurizing solenoid valves 30 and 40 are turned off to open the brake pipe 15. Then, when you depress the brake pedal 13 and operate the foot brake,
Four-wheel wheel cylinder 1 by master cylinder 14
Brake pressure Pb is generated at 7 and 19 to allow arbitrary braking. At this time, in the pressurizing source 34, the pump 24 is operated by the motor control so that a high accumulator pressure is constantly accumulated in the accumulator 29.

Thereafter, in step S2, the operation of the automatic brake selection switch 52 is checked, and if the switch is OFF, the process proceeds to step S3 to cancel the automatic brake and always set the foot brake operable state.

If the switch is ON, the process proceeds to step S4 to check the automatic brake actuation flag F, and if F = 0, the process proceeds to step S5 to check the vehicle speed V. When the vehicle is traveling, the process proceeds to step S6 to check the presence or absence of a preceding vehicle. If the relative distance L is equal to or less than the set value Ls and there is a preceding vehicle, the speeds of the preceding vehicle and the own vehicle are subtracted in step S7. Check the relative velocity Vs. When the relative speed Vs decreases, the possibility of contact is judged and an approach warning is given in step S8. In addition, there is no preceding vehicle because the vehicle is stopped other than this and the relative distance Ls is large.
Under the condition that the relative speed Vs is large and the vehicle is separated, it is determined that there is no possibility of contact, and the automatic brake operation flag F is cleared in step S11.

In case of approach warning, the negative target acceleration Gt, the actual acceleration G, and the deviation ΔG between them are read in step S9. Then, in step S10, the brake switch 53 is used to check the presence or absence of the foot brake operation. When the switch is turned on by the brake operation, it is determined that the driver has avoided contact, and in step S11 the automatic brake operation flag F is cleared. On the other hand, if there is no brake operation,
Proceeding to step S12, the automatic brake operation is performed, and the automatic brake operation flag F is set in step S13.

In the automatic brake operation, the negative target acceleration G
The brake pressure is automatically controlled based on t, the actual acceleration G, and the deviation ΔG between the two. First, before initial deceleration, Gt <0, |
The brake pressure is controlled to an initial value under the conditions of ΔG |> a, ΔG <0, G> 0. Then, when deceleration is started, a negative actual acceleration G is generated, and the negative actual acceleration G is the negative target acceleration G.
When it becomes larger than t and ΔG> 0, pressure reduction control is performed.
If the negative actual acceleration G is smaller than the negative target acceleration Gt and ΔG <0, the pressurization control is performed. Further, when the absolute value of the deviation | ΔG | falls within the control dead zone a, the holding control is performed.

Therefore, the automatic brake hydraulic unit 2 shown in FIG.
In No. 1, the pressure reducing solenoid valves 30 and 40 are initially turned on and closed, and the brake pipe 15 is disconnected from the master cylinder 14. At this time, the pressurizing solenoid valves 32 and 42 are turned on at a predetermined initial duty ratio Di to generate an initial brake pressure in the wheel cylinders 17 and 19 of the four wheels by the accumulator pressure to start deceleration. After that, in the pressure reducing control, the pressurizing solenoid valves 32 and 42 are closed by OFF to stop the introduction of the accumulator pressure and the like, and the pressure reducing solenoid valves 30 and 40 are turned OFF at a predetermined duty ratio D, so that the brake pressure is increased. Through the oil reservoir 22 and decreases. In the pressurization control, the pressure reducing solenoid valves 30 and 40 are turned on again to close, and at this time, the pressurizing solenoid valve 3 is closed.
2, 42 are turned on at a predetermined duty ratio D, and the brake pressure is increased by the accumulator pressure.

In the holding control, the pressurizing solenoid valves 32, 4
2 is off and closed, pressure reducing solenoid valves 30 and 40 are on
Closed, so that the brake pressure is kept constant by containment. As a result, the brake pressures of the P system and the S system simultaneously increase automatically at a predetermined increase rate, and the automatic braking operation is performed so as to brake the vehicle. In this case, feedback control is performed so that the actual acceleration G follows the negative target acceleration Gt, so that the vehicle is safely braked and contact with the preceding vehicle is prevented.

During the automatic brake operation, step S
From step 4 to step S14, the vehicle speed V is checked, and when the vehicle is traveling, the procedure proceeds to step S5 and thereafter to determine the automatic brake satisfaction condition again. If not satisfied, the automatic brake operation flag is cleared in step S11 to release the automatic brake. To do. When the vehicle stops at V = 0 in the automatic brake operating state, the target acceleration Gt becomes very small, so the brake pressure is controlled to be low.
Control of pressurization, pressure reduction, and holding by energization of 40 and 42 is continuously maintained in a stopped state, and contact with a preceding vehicle in a stopped state is also prevented.

In this case, the process proceeds from step S14 to step S15 to determine whether or not a predetermined time ts has elapsed,
Before the elapse, the process proceeds to step S10 and thereafter. When the automatic brake stops and the predetermined time ts has elapsed, step S1
6, the alarm is issued by the automatic brake warning lamp 70, and then the process proceeds to step S10 to check the state of brake operation.

Therefore, the alarm prompts the driver to operate the foot brake or the parking brake. Then, when the driver notices and operates the foot brake to turn on the brake switch 53, the automatic brake operation flag is cleared in step S11 to release the automatic brake, and the operation by energizing the solenoid valve is stopped. For this reason, the pressure increasing / decreasing solenoid valves 30, 32, 40, 4 when the automatic brake is stopped
Coil damage due to continuous energization of 2 and increase in power consumption are prevented in advance.

Next, the control of another embodiment of the present invention when the automatic brake is stopped will be described with reference to the flowchart of FIG. 7 and the time chart of FIG. This control is performed when the automatic brake is stopped and two sets of pressure increasing / decreasing solenoid valves 30 and 32 of P system and S system of two diagonal systems of the brake system of FIG.
With respect to 40 and 42, a vehicle stop holding control pattern is set in which one is pressurized and held and the other is released, and the automatic braking operation is alternately performed at predetermined time intervals with this control pattern.

Therefore, in step S21, it is determined whether or not the automatic braking is being performed. If the automatic braking is being performed, the process proceeds to step S22, the vehicle speed V is checked, and the vehicle is stopped in the automatic braking state.
It proceeds to step S23. Then, as shown at time t1 in FIG. 8, in the P system, the pressurizing solenoid valve 32 is turned off and the pressure reducing solenoid valve 30 is turned on to perform the holding control to perform the automatic braking operation.
In the system, the pressurizing solenoid valve 42 and the depressurizing solenoid valve 40 are turned off to release. After that, when a predetermined time ts elapses,
The process proceeds from step S24 to step S25 to check the control flag F2. Initially step S by F2 = 0
In step 26, the pressure solenoid valve 32 and the pressure reducing solenoid valve 30 are released in the P system to turn them off, and the pressure reducing solenoid valve 40 is turned on in the S system to temporarily turn on the pressure solenoid valve 42 as shown at time t2 in FIG. After turning on, it turns off, pressurizes and holds, and the automatic brake operates.

When the predetermined time ts elapses, the process proceeds from step S27 to step S28 to set the control flag F2. Therefore, next time, from step S25 to step S29, the pressurizing solenoid valve 42 and the pressure reducing solenoid valve 40 are released by OFF in the S system and the pressure reducing solenoid valve 30 is turned ON in the P system as at time t3 in FIG. Pressurizing solenoid valve 32 is temporarily turned on and then turned off to pressurize,
Hold and activate the automatic brake. When the predetermined time ts elapses, the process proceeds from step S30 to step S31 to clear the control flag F2. The same control is repeated thereafter.

As a result, one of the P system solenoid valve and the S system solenoid valve is automatically braked and kept in the stopped state, while the other is rested every predetermined time ts. For this reason, continuous energization of the solenoid valve is reduced when the automatic brake is stopped, so that damage to the coil, increase in power consumption, etc. are similarly prevented.

Although the embodiments of the present invention have been described above, any automatic brake control can be applied.

[0047]

As described above, in the control device for the automatic brake device according to the first aspect of the present invention, the automatic brake control unit includes the automatic brake selection switch, CC
Based on the signals from the D camera, the vehicle speed sensor, and the brake switch, the possibility of contact between the host vehicle and the object facing the vehicle is determined. If there is the possibility of contact, but there is no operation of the brake pedal, An automatic brake control means for outputting signals of pressurization, holding, and pressure reduction of the brake pressure to each pressure reducing solenoid valve and each pressure solenoid valve, and an automatic brake operating signal from the automatic brake control means. When it is determined that the vehicle is stopped in the automatic brake operation state based on the vehicle speed signal from the vehicle speed sensor, the vehicle is configured to include an alarm output unit that issues an alarm by an alarm device after a predetermined time has elapsed. When the vehicle stops and a predetermined time has passed, an alarm is issued to prompt the driver to operate the brake pedal. By the operation of the rake is released,
It is possible to reliably prevent damage and increase in power consumption due to continuous energization of the pressure reducing solenoid valve and the pressure increasing solenoid valve. Further, it is possible to prevent the alarm from forgetting to turn off the automatic brake selection switch and the situation in which the automatic brake is activated for a long time while the vehicle is congested.

Further, in the control device for the automatic brake device according to the present invention, the automatic brake control unit has the object facing the own vehicle based on the signals from the automatic brake selection switch, the CCD camera, the vehicle speed sensor and the brake switch. When the possibility of contact with the brake pedal is judged and the brake pedal is not operated despite the possibility of contact, the signals of pressurization, holding and pressure reduction of the brake pressure are sent to the P system and the S system. Automatic brake control means for outputting to the pressure reducing solenoid valve and each pressurizing solenoid valve of P system and S system to simultaneously operate the automatic brakes of P system and S system, and the automatic brake operation signal from the automatic brake control means and the above When it is determined that the vehicle is stopped in the automatic braking state based on the vehicle speed signal from the vehicle speed sensor, one of the P system and the S system is pressurized and held and the other is released. Set the pattern, the set pressure,
The holding and releasing signals are alternately output to the P-system pressure reducing solenoid valve and pressurizing solenoid valve and the S-system pressure reducing solenoid valve and pressurizing solenoid valve at predetermined time intervals to automatically output the P-system and S-system. With the configuration including the vehicle stop control means for alternately operating the brakes, the continuous energization time of the pressure reducing solenoid valve and the pressure applying solenoid valve is shortened, and it is possible to reliably prevent the coil from burning and the increase in power consumption. In order to keep the automatic brake operating state, its function is effectively demonstrated,
It is effective when stopping and running repeatedly.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a configuration of a first control device of an automatic braking device according to the present invention.

FIG. 2 is a claim correspondence diagram showing a configuration of a second control device of the automatic brake device according to the present invention.

FIG. 3 is an explanatory diagram showing an outline of a vehicle drive device and a brake device.

FIG. 4 is a hydraulic circuit diagram showing a hydraulic unit of the automatic brake device.

FIG. 5 is a functional block diagram showing a configuration of an automatic brake control unit.

FIG. 6 is a flowchart showing a control of automatic braking and an alarm when the automatic brake is stopped as a first embodiment.

FIG. 7 is a flowchart showing P-system and S-system brake control of two diagonal systems when the automatic brake is stopped as a second embodiment.

FIG. 8 is a time chart showing an operating state of the second embodiment.

[Explanation of symbols]

 13 brake pedal 14 master cylinder 16,18 brake line 17,19 wheel cylinder 26,44 line 34 pressure source 30,40 pressure reducing solenoid valve 32,42 pressure solenoid valve 50 CCD camera 51 vehicle speed sensor 52 automatic brake selection switch 53 brake switch 70 automatic brake warning lamp (alarm) C1 automatic brake control means C2 alarm output means C3 vehicle stop control means

Claims (2)

[Claims] 1. A depressurizing solenoid valve is provided in a brake pipe line that connects a master cylinder that generates a brake pressure in response to an operation of a brake pedal of a vehicle and a wheel cylinder that brakes a wheel in accordance with the brake pressure. An automatic brake hydraulic unit in which a pipeline from a pressurizing source communicates with the brake pipeline downstream of the pressure reducing solenoid valve via the pressure solenoid valve, and an automatic brake selection switch for selecting activation / deactivation of the automatic brake, The operation of the pressure reducing solenoid valve and the pressure applying solenoid valve is controlled based on signals from a CCD camera that monitors the front of the vehicle, a vehicle speed sensor that detects the vehicle speed, and a brake switch that detects whether or not the brake pedal is operated. An automatic brake device comprising an automatic brake control unit, wherein the automatic brake control unit is Based on the signals from the dynamic brake selection switch, CCD camera, vehicle speed sensor, and brake switch, the possibility of contact between the host vehicle and the opposite object is judged, and the brake pedal is operated even if there is the possibility of contact. If there is not, the brake pressure increasing, holding, and pressure reducing signals are output to the pressure reducing solenoid valves and the pressure increasing solenoid valves, and the automatic brake control means for operating the automatic brake, and the automatic brake control means An automatic brake comprising: an alarm output means for issuing an alarm by an alarm device when a stop of the vehicle in the automatic brake operating state is judged based on the automatic brake operating signal and the vehicle speed signal from the vehicle speed sensor. The control device of the device. 2. A decompression is provided in a P-system brake pipeline of two diagonal systems which connects a master cylinder that generates a brake pressure in response to an operation of a brake pedal of a vehicle and a wheel cylinder that brakes a wheel in accordance with the brake pressure. A solenoid valve is provided, another pressure reducing solenoid valve is provided in the S-system brake line, and one line from the pressure source is provided downstream of the pressure reducing solenoid valve in the P-type brake line. And an automatic brake hydraulic unit in which the other line from the pressurizing source communicates with the downstream side of the pressure reducing solenoid valve of the S system brake pipeline via the pressure solenoid valve. , Automatic brake selection switch to select whether to operate the automatic brake, CCD camera to monitor the front of the vehicle, vehicle speed sensor to detect the speed of the vehicle, detect the presence or absence of brake pedal operation In the automatic brake device including an automatic brake control unit that controls the operation of each pressure reducing solenoid valve and each pressurizing solenoid valve based on each signal from the brake switch, the automatic brake control unit controls the automatic brake selection. When the possibility of contact between the host vehicle and an object facing the host vehicle is judged based on the signals from the switch, CCD camera, vehicle speed sensor, and brake switch, and there is the possibility of contact, but the brake pedal is not operated Outputs the signals for pressurizing, holding, and depressurizing the brake pressure to the pressure reducing solenoid valves of the P and S systems and the pressure solenoid valves of the P and S systems to automatically brake the P and S systems. Based on an automatic brake actuation signal from the automatic brake control means and a vehicle speed signal from the vehicle speed sensor. When it is determined that the vehicle is stopped in the automatic brake operating state, a vehicle stop holding control pattern that pressurizes and holds one of the P system and S system and releases the other is set, and the set pressurizing, holding, and releasing signals are set. P
System depressurization solenoid valve and pressurization solenoid valve and S system depressurization solenoid valve and pressurization solenoid valve are alternately output at predetermined time intervals, and a stop control for alternately activating the P system and S system automatic brakes. And a control device for an automatic braking device.