JP2705727B2 - Brake control device for motorcycle anti-lock control system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antilock control system, and more particularly, to a brake control device in a motorcycle antilock control system.

Conventional technology The anti-lock control system
When the wheel is locked and starts to slide on the road surface, the brake cylinder fluid pressure (hereinafter referred to as brake fluid pressure) is automatically reduced to reduce the degree of braking, contrary to the driver's braking operation. It is a system to cancel.

FIG. 1 shows an example of a brake hydraulic system for a rear wheel of a motorcycle. When the brake pedal is depressed, the hydraulic pressure in the brake cylinder 2 increases, and the brake 4 of the rear wheel is operated via the intake solenoid valve 3 to operate. When the rear wheel locks due to over-tightening of the brake, the anti-lock control system works and the intake solenoid valve 3
Is displaced to the gentle pressure increasing position, and the exhaust solenoid valve 6 is displaced to the conduction position for the calculated predetermined time ΔT. As a result, the hydraulic pressure applied to the brake 4 decreases, the brake 4 is weakened, and the rear wheel can be released from the locked state.

A similar brake hydraulic system is also provided on the front wheel of a motorcycle, and a brake cylinder is driven by a hand lever. Since the brake hydraulic systems for the front wheels and the rear wheels are provided independently of each other, it is possible to apply a brake to the front wheels or the rear wheels alone.

Problems to be Solved by the Invention In general, the characteristics of the brake fluid pressure change non-linearly as shown in FIG. 2a. The 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 the conventional device, since the brake pressure or the decompression time is not corrected in accordance with the estimated value thereof, for example, on a low μ road surface having a low friction coefficient μ such as an icy road surface or a snowy road, the anti-lock system is not used. Since the control is started in a state in which the brake fluid pressure is low, the wheel slip amount is unnecessarily increased due to the insufficient pressure reduction amount, resulting in a decrease in steering performance and a decrease in vehicle stability. On the other hand, on high-μ roads with a high friction coefficient μ such as asphalt, anti-lock control is started with high brake fluid pressure, so the vehicle deceleration fluctuates due to excessive pressure reduction and the braking distance increases. Occurs.

In order to solve such a problem, the applicant of the present application has disclosed a means for outputting a brake fluid pressure reduction signal K necessary for releasing the lock sign and a current brake cylinder fluid pressure in the earlier patent application. Means and a correction value α according to the current hydraulic pressure of the brake cylinder, and the correction value α
Is added to the pressure reduction signal K, and means for reducing the hydraulic pressure of the brake cylinder using the corrected pressure reduction speed (K + α) has been proposed. In addition to using a hydraulic pickup as a means for detecting the hydraulic pressure of the brake cylinder, especially in the case of a four-wheeled vehicle, since the brake hydraulic pressure and the vehicle deceleration are always in a proportional relationship, a vehicle deceleration sensor can be used, A method of calculating a vehicle deceleration from the estimated vehicle speed and obtaining a correction value α from the calculated vehicle deceleration (see FIG. 3) has been proposed.

However, in the case of two-wheeled vehicles, the brake operation can be performed separately for the front wheel and the rear wheel, so the vehicle body deceleration during anti-lock during single wheel braking or anti-lock during single-wheel braking during front and rear wheel braking is directly applied to the brake fluid pressure. And the situation described below occurs.

The vehicle deceleration at which the brakes are applied to both the front and rear wheels and a sign of locking begins to appear at the same time on both wheels (hereinafter referred to as both wheel limit vehicle deceleration) changes according to the road surface having various friction coefficients μ.
Also, even if the brakes are applied to both the front and rear wheels, the brake balance before and after the front and rear wheels will be lost, and only one wheel will start to show signs of locking. The vehicle deceleration at which one of the front and rear wheels brakes is applied when locking, for example, and the sign of locking begins to appear (hereinafter referred to as one-wheel limit vehicle deceleration) also changes depending on the road surface with various friction coefficients μ. Both wheels are less than the critical vehicle deceleration, which indicates locking at the same time. In the case of a two-wheeled vehicle, the anti-lock control system is usually configured on the assumption that the brakes are applied to both the front and rear wheels. Only when the brake is applied and antilock control is performed, the vehicle deceleration is determined to be small, and the correction value α obtained from the graph of FIG. 3 takes a large value, and as a result, the corrected pressure reduction signal (K + α) becomes large. As a result, the decompression time of the brake fluid pressure becomes longer than necessary. Therefore, there is a problem that the deceleration amount is too large and the vehicle deceleration during the antilock control fluctuates or becomes insufficient.

The present invention provides an anti-lock system that automatically adjusts valves provided in brake hydraulic systems for front and rear wheels of a two-wheeled vehicle to reduce the hydraulic pressure of a brake cylinder, and individually releases the lock sign for the front and rear wheels. In the lock control system,
A brake control device of a two-wheeled vehicle anti-lock control system that can perform the same anti-lock control as when both wheels are subjected to anti-lock control even when one of the front wheels and the rear wheels is under anti-lock control. The purpose is to propose.

Means for Solving the Problems In order to achieve this object, a brake control device according to the present invention includes a means for detecting a vehicle body deceleration and only one of a front wheel and a rear wheel is subjected to antilock control. Means for discriminating that the vehicle is decelerating, and if the discriminating means determines that only one of the front wheels and the rear wheels is under antilock control, the detected vehicle deceleration is increased by a predetermined factor. It is characterized by having speed increasing means and means for performing antilock control of the one wheel based on the increased vehicle deceleration.

Action Detects the case where anti-lock control is performed only on one of the front and rear wheels of a motorcycle, and increases the vehicle deceleration at that time by a specified factor to correct the increase, and uses the corrected value to perform anti-lock. Correct the decompression speed for control.

Embodiment FIG. 4 is a block diagram of a brake control device in an antilock control system for a motorcycle according to the present invention. S0 and S1 are wheel speed sensors that detect the speed of the front and rear wheels, respectively. STP0 and STP1 are stop switches for turning on the brake lamps when the front and rear wheels are braked, respectively, and CAL is the wheel speed. L0, L1 is a lock sign detection unit that detects a lock sign for each wheel, and T0, T1 is a lock sign detection unit that detects a lock sign for each wheel from the vehicle deceleration sensor P. A pressure reduction time setting unit that receives a value proportional to the brake fluid pressure and sets a pressure reduction time required for executing antilock control for each wheel. Further, OUT0 and OUT1 are solenoid command output units that output drive commands to the solenoids of the solenoid valves according to the pressure reduction time, and ACT0 and ACT1 are hydraulic control devices including an intake solenoid valve, an exhaust solenoid valve, and the like. In the above configuration, it is preferable that the arithmetic unit, the lock sign detection unit, the decompression time setting unit, and the solenoid command output unit are configured to be processed by a microcomputer.

Instead of providing the vehicle body deceleration sensor, as shown in FIG. 5, the calculation unit CAL may calculate the estimated vehicle body deceleration from the wheel speed and determine the decompression time based on the calculated vehicle deceleration.

Next, the operation of the brake control device in the antilock control system will be described with reference to the flowchart of FIG. Although only one wheel is described in this flowchart, the same control operation is performed on the other wheels.

In step # 1, the wheel speed, the wheel deceleration, and the estimated vehicle deceleration are calculated. The method of calculating the estimated vehicle body deceleration may be, for example, the method described in detail in Japanese Patent Application No. 62-334038, or another known method.

In step # 2, the presence or absence of a lock sign is detected. As one of the detection methods of the lock sign, when the wheel speed is equal to or less than a predetermined wheel speed threshold value and the wheel deceleration is equal to or less than the predetermined wheel deceleration threshold value, there is a method of determining that there is a lock sign. A known method may be used. If a lock sign is detected, set a flag in step # 3,
If the anti-lock timer is cleared but no sign of lock is detected, the flag is reset in step # 4 and the anti-lock timer is incremented.

In step # 5, it is detected whether or not the flag is set. If the flag is not set, the antilock timer is compared with a predetermined value, for example, 128. When the flag is larger, the antilock control is not performed. The amount of operation of the brake pedal or brake lever is transmitted directly to the brake. Conversely, when the antilock timer value is smaller than 128, antilock control is continued to perform gentle pressurization.

On the other hand, if the flag is set in step # 5, pressure reduction is required under antilock control, and in step # 6, a desired pressure reduction amount ΔW per unit time Δt is set, and this is realized. Pressure signal K is set for this purpose (FIG. 2b).

For example, K = | DECEL | DECEL may be obtained from the wheel deceleration. This desired pressure reduction gradient R may be gentler than the average gradient of the pressure reduction curve of the normal brake fluid pressure as shown in FIG. 2b. In such a case, the pressure is not intermittently reduced but is reduced intermittently. In order to perform the intermittent pressure reduction, for example, in FIG. 1, the intake solenoid valve 3 may be first set to the relaxed pressure state, and the exhaust solenoid valve 6 may be set to the intermittent conduction state.

Steps # 8 to # 15 are steps for correcting the vehicle body deceleration VCEL shown in Table 1 below.
The correction value α is corrected by this correction.

In Table 1, when the antilock control is not executed for both the front and rear wheels, or when both the front and rear wheels are executed, the value VCEL ′ after the vehicle body deceleration correction is the same as the value VCEL before the correction. Used. On the other hand, if the front wheels are under anti-lock control and the rear wheels are not under anti-lock control, the correction value VCEL 'is determined by whether the rear wheel stop switch STP is on or off.
When OFF, the correction value VCEL '= VCEL × 1.5, while when ON, the correction value VCEL' = VCEL × 1.25.
If the front wheels are not under the anti-lock control and the rear wheels are under the anti-lock control, the front wheel stop switch ST
The correction value VCEL 'differs depending on whether P is on or off. When P is off, the correction value VCEL' = VCEL × 2.5, while when P is on, the correction value VCEL '= VCEL × 1.75.

In order to make the above determination, a step # 8 for determining whether or not the other wheel is under the antilock control, a step # 9 for determining whether the stop switch STP of the other wheel is on or off,
Steps # 10 and # 11 for determining whether the currently detected wheel is the front wheel, and step # 1 for increasing the vehicle deceleration by a predetermined number
2, # 13, # 14, and # 15 are provided. Then, in step # 16, a correction value α corresponding to the corrected vehicle deceleration is obtained based on the graph shown in FIG.

For example, when only the front wheels are braked and the anti-lock control is executed, the one-wheel limit vehicle deceleration VCEL calculated in step # 15 is multiplied by 1.5 in step # 15 and corresponds to the two-wheel limit vehicle deceleration. The value VCEL 'is determined. In this case, if the vehicle deceleration VCEL was 0.4G,
The corrected vehicle deceleration VCEL 'is 0.6G. This allows
This means that the value of the correction value α has been corrected from 5 to 0 (third
See figure). As described above, when only one wheel receives the anti-lock control, the two-wheel limit vehicle deceleration VCE which would be obtained if both the front and rear wheels received the anti-lock control.
The correction value α is obtained from the graph of FIG. 3 based on the corrected vehicle deceleration VCEL ′ after the increase is corrected to L ′. At this time, since the correction magnification of VCEL differs depending on the height of the center of gravity of the vehicle and the length of the wheelbase, it may be set arbitrarily according to each vehicle. That is, the corrected vehicle deceleration VCEL 'is a value that would be obtained if both the front and rear wheels were subjected to antilock control. During braking, a load shift to the front axle occurs, and the front wheel braking generates a vehicle deceleration that is closer to the braking of both wheels than the braking of the rear wheel. The maximum correction amount (2.5 times) is set when only the rear wheels are braking from the output of the stop switch STP.

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

Table 2 shows the solenoid opening / closing coefficient J and the solenoid on / off.
An example of the duty ratio to turn off is shown.

Effect of the Invention The brake control device in the anti-lock control system for a motorcycle according to the present invention calculates the vehicle deceleration VCEL 'when one of the wheels receives the anti-lock control even if one of the wheels receives the anti-lock control. The anti-lock control can be performed with an appropriate amount of pressure reduction without causing the pressure reduction time of the brake fluid pressure to be unnecessarily long and excessive pressure reduction.

In addition, when one wheel receives the antilock control, the vehicle deceleration VCEL 'is calculated by determining whether the other wheel not receiving the antilock control is in a braking state, so that a more detailed situation , The anti-lock control can be performed with a more appropriate amount of pressure reduction. Therefore, anti-lock control is always performed stably without distinction between one wheel and both wheels.

[Brief description of the drawings]

1 is a block diagram of a brake hydraulic system, FIG. 2a is a graph showing a change in brake hydraulic pressure, FIG. 2b is a graph showing a pressure reduction signal K of the brake hydraulic pressure, and FIG. 3 is a correction value α. FIG. 4 is a block diagram showing a brake control device in the anti-lock control system for a motorcycle according to the present invention, and FIG. 5 is a block diagram showing a modification of FIG. FIG. 6 is a flowchart of the brake fluid pressure control. 2 Brake cylinder, 4 Brake, 6 Solenoid valve, S0, S1 Wheel speed sensor, L0, L1 Lock sign detection unit, T0, T1 Decompression time setting unit, OUT0, OUT1
… Solenoid command output unit, ACT0, ACT1… Hydraulic pressure control device, P0, P1… Hydraulic pressure detection device.

Claims (5)

(57) [Claims] 1. The brake pressure of a brake cylinder is reduced by automatically adjusting a valve provided in a brake hydraulic system for each of a front wheel and a rear wheel of a two-wheeled vehicle, and a lock sign is individually released for a front wheel and a rear wheel. Means for detecting body deceleration (VCEL) in anti-lock control system (step # 1)
Means for determining that only one of the front wheel and the rear wheel is receiving the anti-lock control (step # 8); and the determination means controls only one of the front wheel and the rear wheel to perform the anti-lock control. If it is determined that the vehicle body is decelerated, the detected vehicle body deceleration is increased by a predetermined factor (Step # 9-Step # 15). Means for performing anti-lock control of wheels (step {16-step}
18) A brake control device for an anti-lock control system of a motorcycle, comprising: 2. The brake pressure of the brake cylinder is reduced by automatically adjusting the valves provided in the brake hydraulic system for each of the front wheel and the rear wheel of the two-wheeled vehicle, and the lock signs are individually released for the front wheel and the rear wheel. Means for detecting body deceleration (VCEL) in anti-lock control system (step # 1)
Means for outputting a pressure reduction signal K required to release the lock sign (step # 6); means for determining that only one of the front wheel and the rear wheel is under antilock control (step # 6) 8) When the discriminating means determines that only one of the front wheels and the rear wheels is under the antilock control, the detected vehicle deceleration is increased by a predetermined factor. (Step # 9-Step # 15) and correcting the pressure reduction signal K based on the increased vehicle deceleration,
A brake control device for an anti-lock control system for a motorcycle, comprising: means (step # 16-step # 18) for performing anti-lock control on the one wheel using the corrected value. 3. The brake control device according to claim 1, wherein said vehicle body deceleration increasing means determines whether or not the other wheel not subjected to the antilock control is braked. Characterized by having a step # 9). 4. The brake control device according to claim 1, wherein said vehicle deceleration increasing means further comprises means for determining whether said one wheel is a front wheel or a rear wheel. 11). 5. The brake control device according to claim 1, wherein said vehicle body deceleration increasing means further includes a case where the brake is applied to the other wheel which has not been subjected to the antilock control. , One of the wheels is a front wheel and a rear wheel is a four-way combination.
It is characterized by having the following multiplication factors.