JPH02241865A - Brake control device for anti-lock control system of motorcycle - Google Patents

Abstract

PURPOSE:To perform anti-lock control based on the increased car body deceleration and invariably obtain the stable braking performance by increasing the detected car body deceleration by preset times when only one of the front and rear wheels is judged to receive anti-lock control. CONSTITUTION:When a brake pedal 1 is depressed to generate the braking force on a brake 4 during the running of a motorcycle, if the wheel speed is the preset wheel speed threshold value or below and the wheel deceleration is the preset wheel deceleration threshold value or below, the motorcycle is judged to be in a lock tendency, and anti-lock control is performed. An intake solenoid valve 3 is closed, an exhaust solenoid valve 6 is opened, and the brake liquid pressure of the brake 4 is reduced. If it is judged that only one of the front and rear wheels receives anti-lock control, the car body deceleration detected by a detecting means is increased by preset times, and the anti-lock control of one wheel is performed based on the increased car body deceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an anti-lock control system, and more particularly to a brake control device in an anti-lock control system for two-wheeled vehicles.

(The anti-lock control system automatically controls the hydraulic pressure in the brake cylinder (hereinafter referred to as brake fluid This system lowers the brake pressure (2) to weaken the degree of brake application and unlock the wheels.

FIG. 1 shows an example of a brake hydraulic system for the rear wheel of a two-wheeled vehicle.

When the brake pedal is depressed, the hydraulic pressure within the brake cylinder 2 is activated to tighten the rear wheel brake 4 via the intake solenoid valve 3. When the rear wheels are locked due to excessive tightening of the brakes, the anti-lock control system is activated to displace the intake solenoid valve 3 to the gradual pressure increasing position and to displace the nitrogen thrust solenoid valve 6 to the conductive position for a calculated predetermined time ΔT. As a result, the hydraulic pressure applied to the brake 4 is reduced, the brake 4 is weakened, and the rear wheels can be released from the locked state.

A similar brake hydraulic system is also provided for the front wheels of two-wheeled vehicles, and the brake cylinders are driven by hand levers. Note that the brake hydraulic systems for the front wheels and the rear wheels are provided independently, so it is possible to brake the front wheels or the rear wheels alone.

Problems to be Solved by the Invention In general, the characteristics of brake fluid pressure change non-linearly as shown in Figure 2a. The pressure reduction width ΔP is large. Therefore, in order to obtain a desired pressure reduction width, the pressure reduction time ΔT must be changed depending on the brake fluid pressure.

However, in conventional devices, brake fluid pressure or depressurization time correction is not performed according to its estimated value, so anti-lock failure occurs on low-μ roads such as icy or snowy roads, where the friction coefficient μ is low. Since the control is started when the brake fluid pressure is low, the amount of wheel slip increases unnecessarily due to the insufficient amount of pressure reduction, resulting in a decrease in steering performance and vehicle stability. On the other hand, on roads with a high friction coefficient μ such as asphalt, anti-lock control is started with high brake fluid pressure, resulting in problems such as excessive depressurization and changes in vehicle deceleration, resulting in longer braking distances. occurs.

In order to eliminate this problem, the applicant of the present application proposed in a previous patent application a means for outputting a brake fluid pressure reduction signal necessary to release the locking sign and a means for detecting the current brake cylinder fluid pressure. Calculate a correction value α according to the current brake cylinder fluid pressure, add the correction value α to the pressure reduction signal K, and use the corrected pressure reduction speed (K-1α) to adjust the brake cylinder fluid pressure. We have proposed a brake control device characterized by comprising means for reducing pressure.

In addition to using a hydraulic pickup as a means to detect the hydraulic pressure in the brake cylinder, especially in the case of four-wheeled vehicles, the brake hydraulic pressure and vehicle deceleration are always in a proportional relationship, so
We have proposed a method of using a vehicle deceleration sensor or calculating the vehicle deceleration from the estimated vehicle speed and then obtaining the correction value α (see FIG. 3).

However, in the case of motorcycles, it is possible to operate the brakes on the front and rear wheels separately, so the deceleration of the vehicle body when braking on one wheel cannot be directly converted to brake fluid pressure, resulting in the situation described below. do.

The vehicle body deceleration at which the brakes are applied to both the front and rear wheels and signs of locking begin to appear (hereinafter referred to as the limit vehicle body deceleration for both wheels) changes depending on the road surface with various friction coefficients μ. In addition, the front wheel
Vehicle deceleration at which signs of locking begin to appear when either rear wheel brake is applied (hereinafter referred to as one-wheel limit vehicle deceleration)
Although the coefficient of friction μ changes depending on the road surface, it is smaller than the limit vehicle deceleration of both wheels by a predetermined ratio. In the case of two-wheeled vehicles, anti-lock control systems are usually configured on the assumption that the brakes are applied to both the front and rear wheels, so if anti-lock control is performed with the brakes applied to only one wheel, the deceleration of the vehicle will be reduced. is determined to be small, and the correction value α obtained from the graph of FIG. 3 takes a large value, resulting in a large corrected pressure reduction signal (K+α) and a longer brake fluid pressure reduction time than necessary. Therefore, the depressurization is too large, causing a problem that the deceleration of the vehicle body fluctuates or becomes insufficient during anti-lock control.

The present invention automatically adjusts the valves installed in the brake hydraulic system of the front and rear wheels of a two-wheeled vehicle to reduce the hydraulic pressure in the brake cylinder, thereby releasing the anti-lock signal for the front and rear wheels individually. [In one control system,
Either the front or rear wheels are subject to anti-lock control.
The present invention aims to propose a brake control device for an anti-lock control system for a two-wheeled vehicle that can perform anti-lock control similar to when both wheels are subjected to anti-lock control.

Means for Solving the Problems To achieve this object, the brake control device according to the present invention includes means for detecting vehicle deceleration, and only one of the front wheels and rear wheels is subjected to anti-lock control. and a vehicle body deceleration system that increases the detected vehicle body deceleration by a predetermined time if the determination means determines that only one of the front wheels and rear wheels is under antilock control. The vehicle is characterized by comprising a speed increasing means and a means for performing anti-lock control on the one wheel based on the increased vehicle body deceleration.

Detects when anti-lock control is applied to only one of the front and rear wheels of a two-wheeled vehicle, increases the vehicle body deceleration at that time by multiplying it by a predetermined value, and uses the corrected value to perform anti-lock control. Correct the decompression speed for control.

FIG. 4 shows a block diagram of a brake control device in an anti-lock control system for a two-wheeled vehicle according to the present invention. SO and SL are wheel speed sensors, 5TPO, that detect the speed of the front and rear wheels, respectively.

5TPI is a stop switch that turns on the brake light when a brake is applied to the front and rear wheels, respectively.
CA I is a calculation unit that calculates wheel deceleration, estimated vehicle speed, and estimated vehicle deceleration from wheel speed; LO and Ll are lock symptom detection units that detect lock symptoms for each wheel;
TO and TI receive a value proportional to the brake fluid pressure of each wheel from the vehicle body deceleration sensor P, and are pressure reduction time settings that set the pressure reduction time required for anti-lock control to be executed for each wheel. Department. Furthermore, 0UTO, 0UT1
is a solenoid command output section that outputs a drive command to the solenoid of the solenoid valve according to the pressure reduction time, and ACT
O, ACTI is a hydraulic control device including an intake solenoid valve, a nitrogen intake solenoid valve, etc.

In the above configuration, the calculation section, the lock symptom detection section, the decompression time setting section, and the so! Preferably, the tunoid command output section is configured to be processed by a microcomputer.

In addition, instead of providing a vehicle deceleration sensor, as shown in FIG. good.

Next, the operation of the brake control device included in the anti-lock control system will be explained with reference to the flowchart shown in FIG. In this flowchart, only one wheel will be explained, but it is assumed that similar control operations are performed for the other wheels as well.

In step #1, wheel speed, wheel deceleration, and estimated vehicle body deceleration are calculated. Note that the method for calculating the estimated vehicle body deceleration may be, for example, the method detailed in Japanese Patent Application No. 62-334038, or other known methods may be used.

In step #2, the presence or absence of a lock sign is detected. One method for detecting a lock sign is to determine that a lock sign has occurred when the wheel speed is below a predetermined wheel speed threshold and the wheel deceleration is below a predetermined wheel deceleration threshold. A known method may be used. If a mouth/tsuk sign is detected, set the flag in step #3,
While clearing the anti-lock timer, if no lock sign is detected, the flag is reset in step #4 and the anti-lock timer is incremented.

In step #5, it is detected whether the flag is set, and if it is not set, the anti-lock timer is set to a predetermined value, e.g. 28, when it is large, anti-lock control is not performed and the amount of operation of the brake pedal or brake lever by the driver is directly transmitted to the brakes. Conversely, when the anti-lock timer value is smaller than 28, anti-lock control is continued and gentle pressurization is performed.

On the other hand, if the flag is set in step #5, then depressurization is required under anti-lock control and step #5
At step 6, a desired pressure reduction amount ΔW per unit time Δ is set, and a pressure reduction signal K is set at t-th to realize this (FIG. 2b).

The pressure reduction signal may be determined from the wheel deceleration, for example K = IDECEL. As shown in FIG. 2b, this desired pressure reduction gradient R may be gentler than the average slope of the normal brake fluid pressure pressure reduction curve. In such cases, the pressure is not reduced constantly, but intermittently. In order to perform intermittent pressure reduction, for example, as shown in FIG.
What is necessary is to intermittently bring the Nigeshiest solenoid valve 6 into a conductive state.

Step #8 to step #ist are steps for correcting the vehicle body deceleration VCEL shown in Table 1 below, and the correction value α is corrected by this correction.

(Left below) Table 1 Anti-lock control STP Vehicle deceleration sensor list Liaoni - Eaves wheel 1. Kamebee VCEL'X
---YCEl,.

Q　　　Q　　　　---VCEI.

○ X -X VCELXl, 5Q
X-OVCELXl, 25X OX
-VCELX 2.5 uses the pre-correction value V CEI, , as is.

On the other hand, if the front wheels are under anti-lock control and the rear wheels are not under anti-lock control, the rear wheel stop switch STP
The correction value VCEL' differs depending on whether it is on or off, and if it is off, the correction value VCEL° = VCEL x 1.5.
If onte is present, correction value VCEI,' = VCELx 1
．． It becomes 25. Also, if the front wheels are not under anti-lock control and the rear wheels are under anti-lock control, the correction value VCEL' will be determined depending on whether the front wheel stop switch STP is on or off.
are different, and if it is off, the correction value VCEll-VCE[,
, X2.5. On the other hand, if it is on, the correction value VCEL'
= VCELx 175.

In order to make the above judgment, step #8 determines whether the other vehicle width is under anti-lock control, and step #9 determines whether the stop switch STP of the other vehicle width is on or off.
There are steps #10 and #11 in which it is determined whether the currently detected wheel is the front wheel, and steps #12, #13, #14, and #15 in which the vehicle body deceleration is multiplied by a predetermined value. Then, in step #16, a correction value α corresponding to the corrected vehicle body deceleration is determined based on the graph shown in FIG.

For example, if anti-lock control is executed by applying the brakes only to the front wheels, the one-wheel limit vehicle deceleration VCEL calculated in step #15 is 1.5 in step #15.
A value VCEL' corresponding to the limit vehicle deceleration of both wheels is obtained by multiplying the value. In this case, if the vehicle deceleration VCEL is 0.4
G, the corrected vehicle body deceleration VCEL' becomes Q, 6G. From this, the value of the correction value α has been corrected from 5 to O (see FIG. 3). As shown in Figure 2, if one wheel is subject to anti-lock control, the two-wheel limit vehicle deceleration VCEI, which would be obtained if both the front and rear wheels were subject to anti-lock control, is The correction value α is determined based on the corrected vehicle deceleration VCEL' using the graph shown in FIG. 3. At this time,
Since the correction magnification of VCEl differs depending on the height of the center of gravity and the length of the wheelbase of the vehicle, it may be set arbitrarily depending on each vehicle. 1, that is, the corrected vehicle deceleration VCEL'
is the value obtained if both wheels at the front and rear are subjected to anti-lock control. Furthermore, during braking, the load is transferred to the front axle12, and the vehicle body deceleration occurs when braking the front wheels is closer to when braking both wheels than when braking the rear wheels, so the correction amount is calculated as follows: The maximum correction amount (2°5 times) is set when only the rear wheels are braked I2 from the stop switch STP output.

Next, in step #16, the correction value α is added to the depressurization signal obtained in step #6, and the
A solenoid opening/closing coefficient J for intermittently opening and closing the valve 6 is calculated to set the pressure reduction time.

Table 2 shows an example of the solenoid opening/closing coefficient J and the duty ratio for turning on/off the solenoid.

Table 2 J≧72 0 (as) oo
(ms) 72〉J≧48 6
2448〉”≧36 6
1236〉J≧2466 24〉J≧12 12 6
12>J 24
6J=0 00
0 According to this duty ratio, a solenoid command is output in step #18.

Effects of the Invention The brake control device in the anti-lock control system for a two-wheeled vehicle according to the present invention calculates the vehicle deceleration vcE+, ゛ when both wheels receive anti-lock control even if one wheel receives anti-lock control. 1. Since the correction value α is obtained from this, the brake fluid pressure reduction time is required 1-
It is possible to perform anti-slip control with an appropriate amount of depressurization without causing excessive depressurization due to a long period of time.

Additionally, if one wheel is under anti-lock control, the vehicle body deceleration VCEL' is calculated by determining whether the other wheel, which is not under anti-lock control, is in the braking state or not. Therefore, it is possible to determine the correction value α according to more detailed situations, and it is possible to perform anti-lock control with an appropriate amount of pressure reduction.Therefore, it is possible to always maintain stable anti-lock control regardless of whether one wheel or both wheels are involved. Lock control is performed.

[Brief explanation of drawings]

Figure 1 is a block diagram of the brake fluid pressure system, Figure 2a is a graph showing changes in brake fluid pressure, Figure 2b is a graph showing brake fluid pressure reduction signals (and Figure 3 is a graph showing correction values). α
FIG. 4 is a block diagram of a brake control device that applies to the anti-lock control system for a motorcycle according to the present invention, and FIG. 5 is a modified example of FIG. 4. Fig. 6 is a flowchart of brake fluid pressure control. 2... Brake cylinder, 4... Brake, 6... Solenoid valve, so, si... Wheel speed sensor, LO, Ll... Lock symptom detection section, TO, Tl... Decompression time setting section, OUT O, OUT +... Solenoid command output section,
ACT O, ACT l...hydraulic pressure control device, po, p
i...Fluid pressure detection device. Figure 1 Patent applicant Sumitomo Electric Industries Co., Ltd. agent Patent attorney Aoyama Aoyama and one other person

Claims (1)

[Claims] 1. Automatically adjust the valves installed in the brake fluid pressure system of each of the front and rear wheels of a two-wheeled vehicle to reduce the fluid pressure in the brake cylinder, and provide individual lock signs for the front and rear wheels. In the anti-lock control system that releases the vehicle body deceleration (VCEL),
), a means for determining whether only one of the front wheels or rear wheels is under anti-lock control (step #8), and a means for determining whether only one of the front wheels or rear wheels is under anti-lock control (step #8); If it is determined that the vehicle is under lock control, a vehicle deceleration increasing means (step #9 to step #15) increases the detected vehicle deceleration by a predetermined time; A brake control device for an anti-lock control system for a two-wheeled vehicle, comprising means for performing anti-lock control on one wheel (step #16 to step #18). 2. Anti-lock control that automatically adjusts the valves installed in the brake fluid pressure system of the front and rear wheels of a motorcycle to reduce the fluid pressure in the brake cylinder and release lock signs for the front and rear wheels individually. In the system, means for detecting vehicle body deceleration (VCEL) (step #1
), a means for outputting a decompression signal necessary to release the lock sign (step #6), and a means for determining whether only one of the front wheels or rear wheels is under anti-lock control (step #6). #8) If the determining means determines that only one of the front wheels and rear wheels is under anti-lock control, the vehicle deceleration is increased by increasing the detected vehicle deceleration by a predetermined time. means (step #9 - step #15); correcting the depressurization signal K based on the increased vehicle body deceleration;
A brake control device for an antilock control system for a two-wheeled vehicle, comprising means (step #16 to step #18) for performing antilock control on one wheel using the corrected value. 3. The brake control device according to claim 1 or 2, wherein the vehicle body deceleration increasing means includes means for determining whether or not the other wheel not undergoing anti-lock control is braked (step #9). ). 4. The brake control device according to claim 1 or 2, wherein the vehicle body deceleration increasing means further comprises means for determining whether the one wheel is a front wheel or a rear wheel (step #10, step #2).
11). 5. The brake control device according to claim 1 or 2, wherein the vehicle body deceleration increasing means further controls whether or not the other wheel that is not subjected to anti-lock control is braked, and whether the other wheel is braked or not. The wheels of the present invention are characterized in that four types of increase magnification are provided by four combinations of front wheels and rear wheels.