JP2000233733A - Vehicular brake control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular brake control system which secures an effectiveness incrementing feeling at the latter period of brakeage. SOLUTION: In this vehicular brake control system which is equipped with a reference target G operation part 64 operating reference target deceleration from pedal strokes and master cylinder pressure when a braking requirement is produced by a brake pedal, a target G compensation part 66 operating a build-up quantity to be added to the reference target deceleration, and a braking force control means controlling the braking force of a vehicle on the basis of the target deceleration obtained by the reference target deceleration and the compensation value, the target G compensation part 66 increases the compensation value along with the elapse in the case where an operating speed of the brake pedal is in the specified range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle braking control device which calculates a target deceleration from an operation state of a brake operating means and controls a braking force of the vehicle based on the target deceleration.

[0002]

2. Description of the Related Art Conventionally, there has been known a brake device in which a brake fluid pressure is gradually increased in a later stage of braking to provide a feeling of late biting to improve a braking feeling (see Japanese Patent Application Laid-Open No. 7-81535). In this brake device, the brake fluid pressure is gradually increased by gradually increasing the correction amount with respect to the master cylinder fluid pressure generated by depressing the brake pedal based on a time constant, thereby giving a feeling of late biting in the latter half of braking. .

[0003]

However, in the above-described brake control device, the correction amount for the master cylinder hydraulic pressure is gradually increased based on the time constant. It may be saturated, and when the correction amount is saturated, a biting feeling (a feeling of increasing effect) cannot be obtained thereafter.

[0004] It is an object of the present invention to provide a vehicle brake control device that ensures a feeling of increased effectiveness in the latter half of braking.

[0005]

According to a first aspect of the present invention, there is provided a vehicle braking control device which sets a target deceleration as a value which increases with time and converges at a predetermined value when a braking request is generated by a brake operating means. And a braking force control means for controlling the braking force of the vehicle based on the target deceleration calculated by the calculation means, wherein the operation speed of the brake operation means is detected. The operation speed detecting means, and when the operation speed detected by the operation speed detecting means is within a predetermined range, the calculation means increases the target deceleration with time.

According to a second aspect of the present invention, there is provided a vehicle brake control device, wherein the calculating means of the vehicle brake control device calculates a basic target deceleration from an operation state of a brake operating means. Means, correction amount calculating means for calculating a correction amount as a value that increases with the passage of time only when the operation speed of the brake operation means is within a predetermined range, and a target based on the basic target deceleration and the correction amount. Target deceleration calculating means for calculating deceleration.

According to the first and second aspects of the present invention, the brake operation is performed when the operation speed of the brake operation means detected by the operation speed detection means is depressed within a predetermined range, for example, a predetermined amount. In a case where the means is stopped, the calculating means increases the target deceleration over time by adding a correction amount to the basic target deceleration. Therefore, when the brake operation means is stepped up and returned, the calculation means does not increase the target deceleration by adding the correction amount to the basic target deceleration. It is possible to prevent the target deceleration from converging to the predetermined value on the way, and to prevent the feeling of increase (build-up) in the latter half of braking from being impaired.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a hydraulic brake circuit diagram of an electronic control brake device 10 according to the embodiment. The electronic control brake device 10 has a master cylinder 14 that pumps hydraulic oil in response to a driver's depressing operation of a brake pedal 12. The brake pedal 12 has a stroke sensor 62 (FIG. 2) that detects the amount of depression of the brake pedal, that is, the pedal stroke.
Reference).

A stroke simulator 18 is connected to the master cylinder 14 via a normally open type simulator cut valve 16.
Is connected. A master pressure sensor 24 for detecting the pressure in the master cylinder 14 is provided between the master cylinder 14 and the normally closed master cut valves 20 and 22.
26 are provided.

One end of a hydraulic supply conduit 30 and one end of a hydraulic discharge conduit 32 are connected to the reservoir 28. In the middle of the hydraulic supply conduit 30, a pump 36 driven by a motor 34 is provided.
Is provided, and an accumulator 38 is provided for storing the hydraulic pressure raised by rotating the pump 36. An accumulator pressure sensor 40 for detecting the internal pressure of the accumulator 38 is provided in the middle of the hydraulic supply conduit 30. Furthermore, the hydraulic supply conduit 3
A relief valve 44 for returning hydraulic oil to the reservoir 28 when the pressure in the hydraulic pressure supply conduit 30 becomes high is provided between the pressure supply conduit 30 and the hydraulic pressure discharge conduit 32.

The other end of the hydraulic supply conduit 30 is connected to the left front wheel cylinder 48 via a hydraulic supply conduit 46FL for the left front wheel.
FL, and is connected to a right front wheel cylinder 48FR via a right front wheel hydraulic supply conduit 46FR. The other end of the hydraulic supply conduit 30 is connected to a wheel cylinder 48RL of the left rear wheel via a hydraulic supply conduit 46RL for the left rear wheel, and is connected to a wheel of the right rear wheel via a hydraulic supply conduit 46RR for the right rear wheel. It is connected to the cylinder 48RR.

Similarly, the other end of the hydraulic discharge conduit 32 is connected to a left front wheel wheel cylinder 48FL via a left front wheel hydraulic discharge conduit 50FL, and is connected to a right front wheel wheel cylinder via a right front wheel hydraulic discharge conduit 50FR. Connected to 48FR. The other end of the hydraulic discharge conduit 32 is connected to a wheel cylinder 48RL of the left rear wheel via a hydraulic discharge conduit 50RL for the left rear wheel.
And is connected to a wheel cylinder 48RR of the right rear wheel via a hydraulic discharge conduit 50RR for the right rear wheel.

Hydraulic supply conduits 46FL, 46FR, 46RL, 4
In the middle of 6RR, the electromagnetic flow control valve (holding valve) 52
FL, 52FR, 52RL, 52RR are provided, and electromagnetic flow control valves (pressure reducing valves) 54FL, 54FR, 54R are provided in the middle of the hydraulic discharge conduits 50FL, 50FR, 50RL, 50RR.
L and 54RR are provided. Further, pressure sensors 56FL, 56FR, 56RL, and 56RR are provided to detect respective pressures in the wheel cylinders 48FL, 48FR, 48RL, and 48RR.

As shown in FIG. 2, a signal indicating the pressure in the master cylinder 14 output from the master pressure sensors 24 and 26 and a pressure in the accumulator 38 output from the accumulator pressure sensor 40 are sent to the ECU 60. A signal indicating the pressure in the wheel cylinders 48FL to 48RR output from the pressure sensors 56FL to 56RR is input. Further, a signal indicating the amount of depression of the brake pedal, that is, a pedal stroke is input from the stroke sensor 62 to the ECU 60.

On the other hand, the ECU 60 includes the simulator cut valve 16, the master cut valves 20, 22, the electromagnetic flow control valve 5,
Control signals are output to the motor 34 and the 2FL-52RR, 54FL-54RR.

As shown in FIG. 3, the ECU 60 controls the master cylinder 14 detected by the master pressure sensors 24 and 26.
It functions as a reference target G calculating section 64 for calculating a reference target deceleration based on the internal pressure and the pedal stroke detected by the stroke sensor 62, and a target G correction section 66 for calculating a correction amount of the target deceleration.

When the ignition switch is turned on, the ECU 60 first activates the master cut valve 20,
22 is closed to interrupt communication between the master cylinder 14 and the wheel cylinders 48FL, 48RL.

Next, in the reference target G calculating section 64,
As shown in the flowchart of FIG. 4, a signal indicating the pedal stroke (operating amount of the brake pedal) Sp detected by the stroke sensor 62 and the master pressure sensor 24,
A signal indicating the master cylinder pressure (operating force of the brake pedal) Pm detected by the controller 26 is read (step S1).
0). Next, the target deceleration Gst based on the pedal stroke Sp is calculated by referring to the map shown in FIG. 5 (step S11), and the target deceleration Gst based on the master cylinder pressure Pm is obtained by referring to the map shown in FIG. The speed Gpt is calculated (step S12).

Next, the previously calculated reference target deceleration G *
0, referring to the map shown in FIG. 7, the weight .alpha. (0.ltoreq.0) for the target deceleration Gpt based on the master cylinder pressure Pm.
α ≦ 1) is calculated (step S13). Next, Equation 1
Is calculated as a weighted sum of the target deceleration Gpt and the target deceleration Gst (step S14).

[0020]

(Equation 1)

The target G correction unit 66 calculates the build-up amount according to the flowchart shown in FIG. First, it is determined whether or not the reference target deceleration G * 0 is equal to or more than the constant value A (step S20). That is, when the reference target deceleration G * 0 is not equal to or larger than the fixed value A (when the condition of G * 0> A is not satisfied), the build-up control is not performed, and therefore, the build-up coefficient which is a coefficient for determining the amount of the pillar-up. It is assumed that K = 0 (step S28).

In step S20, if the condition of G * 0> A is satisfied, it is determined whether or not the condition represented by Expression 2 is satisfied (step S21). That is, when the brake pedal 12 is intentionally increased and the brake pedal 1
When the brake pedal 12 has an operation speed within a predetermined range, such as when returning to 2, the determination in step S21 is made in order not to perform the build-up control.

[0023]

(Equation 2)

Next, if the condition of step S21 is satisfied, K = the previous K in order to increase the build-up amount.
+ C is calculated (step S22). Therefore, when the brake pedal 12 is stopped in a depressed state, the value of K, that is, the build-up amount increases with time. Note that C is a constant that determines the speed of build-up. Next, it is determined whether or not K> Kmax (step S23). If this condition is satisfied, K = K
max (step S24). That is, the value of K is converged at a predetermined value and the maximum value is guarded in order to suppress a significant change in the braking characteristic due to an increase in the build-up amount.

Next, a build-up amount (a target deceleration correction amount) △ G * is obtained based on Equation 3 (step S2).
5) It is determined whether or not ＊ G *> △ G * max (step S26). If this condition is satisfied, △ G * = △ G
* Max (step S27). That is, the maximum guard is applied to the build-up amount.

[0026]

(Equation 3)

The ECU 60 obtains the final target deceleration G * from Equation 4 based on the reference target deceleration G * 0 and the target deceleration correction amount ΔG *.

[0028]

(Equation 4)

Next, the target wheel cylinder pressure Pti (i = FL, FR, RL, R) of each wheel with respect to the final target deceleration G *
R). Next, based on the target wheel cylinder pressure Pti of each wheel, the electromagnetic flow control valve (holding valve) 5
The opening and closing of 2FL, 52FR, 52RL, 52RR and electromagnetic flow control valves (reducing valves) 54FL, 54FR, 54RL, 54RR are controlled to control the wheel cylinder pressure of each wheel.

According to the electronic control brake according to this embodiment, the brake pedal 12 is depressed in a state where the brake pedal 12 is depressed by a predetermined amount.
When the brake pedal 12 is stopped, the build-up control is performed, and when the brake pedal 12 is further depressed or returned, the build-up control is not performed.
It is possible to prevent the target deceleration from converging to a predetermined value while the brake pedal 12 is being depressed, and it is possible to prevent a sense of increased effectiveness (build-up) in the latter half of braking from being impaired.

[0031]

According to the present invention, when the operation speed of the brake operation means detected by the operation speed detection means is in a predetermined range, for example, when the brake operation means is depressed by a predetermined amount, the brake operation means is stopped. Since the calculating means increases the target deceleration with the passage of time, it is possible to prevent the target deceleration from converging to a predetermined value while the brake operating means is being depressed. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a hydraulic brake circuit diagram of an electronic control brake device according to an embodiment.

FIG. 2 is a control block diagram of the electronically controlled brake device according to the embodiment.

FIG. 3 shows E of the electronically controlled brake device according to the embodiment;
It is a block diagram which shows the function of CU.

FIG. 4 is a flowchart showing a process in a reference target G calculation unit of the electronic control brake device according to the embodiment.

FIG. 5 is a diagram showing a map used in a reference target G calculation unit of the electronically controlled brake device according to the embodiment.

FIG. 6 is a diagram showing a map used in a reference target G calculation unit of the electronically controlled brake device according to the embodiment.

FIG. 7 is a diagram showing a map used in a reference target G calculation unit of the electronically controlled brake device according to the embodiment.

FIG. 8 is a flowchart illustrating a process of calculating a buildup amount in a target G correction unit of the electronically controlled brake device according to the embodiment;

[Explanation of symbols]

10: electronic control brake device, 12: brake pedal,
14: master cylinder, 20, 22: master cut valve,
24, 26: master pressure sensor, 30: hydraulic supply conduit, 3
2 ... Hydraulic discharge conduit, 48FL-48RR ... Wheel cylinder, 52FL-52RR, 54FL-54RR ... Electromagnetic flow control valve, 60 ... ECU, 62 ... Stroke sensor, 64 ... Reference target G calculation unit, 66 ... Target G correction unit.

Claims (2)

[Claims] 1. A calculating means for calculating a target deceleration as a value which increases with time and converges at a predetermined value when a braking request is generated by a brake operating means, and a target deceleration calculated by the calculating means. A braking control device for a vehicle, comprising: a braking force control unit that controls a braking force of the vehicle based on a speed; an operation speed detection unit that detects an operation speed of the brake operation unit; and an operation detected by the operation speed detection unit. The braking control device for a vehicle according to claim 1, wherein when the speed is within a predetermined range, the calculation means increases the target deceleration with time. 2. The computing means comprises: a basic target deceleration calculating means for calculating a basic target deceleration from an operating state of a brake operating means; and a lapse of time only when the operating speed of the brake operating means is within a predetermined range. A correction amount calculating means for calculating a correction amount as a value increasing with the correction amount, and a target deceleration calculating means for calculating a target deceleration based on the basic target deceleration and the correction amount. 2. The braking control device for a vehicle according to claim 1.