JP3388548B2 - Brake control method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake control method for performing anti-lock braking by changing an anti-lock braking parameter according to the wheel speed. 2. Description of the Related Art In an automobile or a motorcycle, a vehicle body travels in a state where rotation of wheels is stopped during braking.
In order to prevent a so-called brake lock state, an anti-lock braking device has been conventionally used. For example, an anti-lock braking device mounted on a motorcycle includes a master cylinder that converts a brake operation command generated by a driver's lever operation or pedal operation into hydraulic pressure, and a braking force applied to a brake disk of a wheel. It has a caliper cylinder to generate and a modulator arranged between the master cylinder and the caliper cylinder. Then, a change in the wheel speed or a change in the acceleration / deceleration of the wheel is calculated from the wheel speed signals of the front and rear wheels. The antilock braking is performed by controlling the braking force by changing the control parameters and outputting the control signal. In the above-mentioned prior art, the various control parameters are based only on the change in the wheel speed or the change in the acceleration / deceleration of the wheel regardless of the actual wheel speed. has been edited. However, when the wheel speed is low, the wheel speed change (information amount) per unit time is reduced, and the wheel speed signal does not change with respect to the calculation speed of the CPU. There is a problem that antilock braking cannot be performed with high accuracy because the amount of information is small. Further, particularly in a motorcycle, since the bank angle at cornering changes depending on the magnitude of the wheel speed, the method of changing the control parameters based only on the change in the wheel speed or the change in the acceleration / deceleration of the wheel is as follows.
It is difficult to perform optimal anti-lock braking corresponding to the characteristics of the motorcycle. The present invention solves this kind of problem, and it is possible to perform optimal antilock braking in accordance with the magnitude of wheel speed and to perform effective braking according to vehicle body characteristics. It is an object of the present invention to provide a brake control method. [0007] In order to achieve the above object, the present invention relates to a brake control method for a motorcycle, which performs anti-lock braking by controlling a braking force of a wheel. Detecting the wheel speed, obtaining the slip amount and acceleration / deceleration based on the detected wheel speed, and determining that antilock control is necessary based on the slip amount and the acceleration / deceleration. a duty determination process and the process of generating a pulse train, calculates the duty as a function of the wheel speeds are taken in succession, to change the duty of the pulse train directly, Dew
Performing antilock braking based on the pulse train whose tee has been changed . In the brake control method according to the present invention, the slip amount and the acceleration / deceleration are obtained based on the wheel speed, and when it is determined that the antilock control is necessary based on the slip amount and the acceleration / deceleration. to generate a pulse train, calculating a duty as a function of the wheel speeds are taken in succession
Then, the duty of the pulse train is directly changed and output. As a result, anti-lock braking can be accurately performed especially at low speed running or immediately before stopping, and an effective anti-lock braking can be performed according to a change in the vehicle body characteristics of a motorcycle in which the bank angle at cornering changes depending on the wheel speed. Braking is reliably performed with continuity. The brake control method according to the present invention will be described in connection with an apparatus for carrying out the method.
This will be described in detail below with reference to the accompanying drawings. In FIG. 1, reference numeral 10 denotes a motorcycle. The motorcycle 10 includes a main body 12, a handle 14, a step 15, a front wheel 16, and a rear wheel 18. The motorcycle 10 is provided with an antilock braking device 20. As shown in FIGS. 1 and 2,
The anti-lock braking device 20 includes a brake lever 22
The master cylinder 24 for the front wheels is connected to the master cylinder 24 for the front wheels under the action of the brake lever 22.
A front wheel caliper cylinder 26 for applying a braking force to the front wheel portion 16 in accordance with the hydraulic pressure generated in the front wheel, and a front wheel modulator 28 for adjusting the hydraulic pressure generated in the front wheel master cylinder 24 to reduce the braking force. After applying a braking force to the rear wheel portion 18 corresponding to the hydraulic pressure generated in the rear wheel master cylinder 32 under the action of the brake pedal 30 and the rear wheel master cylinder 32 connected to the brake pedal 30. A wheel caliper cylinder 34; a rear wheel modulator 36 for adjusting the hydraulic pressure generated in the rear wheel master cylinder 32 to reduce the braking force; a controller 84; a control unit 86; Sensor 9
2 and 94. The front wheel modulator 28 is disposed between the brake lever 22 and the front wheel section 16, and the front wheel master cylinder 24 and the front wheel modulator 28 are connected to a conduit 38.
And the front wheel caliper cylinder 2
The front wheel modulator 6 communicates with the front wheel modulator 28 via a conduit 40. On the other hand, the rear wheel modulator 36 is disposed between the brake pedal 30 and the rear wheel portion 18, and the rear wheel master cylinder 32 and the rear wheel modulator 36 communicate with each other through the conduit 42. The rear wheel caliper cylinder 34 and the rear wheel modulator 36
Is communicated through. As shown in FIG. 2, the front wheel modulator 2
8 is provided with a casing 46, and the casing 46 has an input port 4 communicating with the front wheel master cylinder 24.
8 and an output port 50 communicating with the front wheel caliper cylinder 26 are formed. The input port 48 and the output port 50 communicate with an input hydraulic chamber 52 and an output hydraulic chamber 54, respectively.
Is maintained in a closed state via a cut valve 58 that engages with the pressing spring 56. The end of the cut valve 58 protrudes into the output hydraulic chamber 54, and can freely contact an expander piston 60 that is provided in the output hydraulic chamber 54 so as to be able to advance and retreat. An accumulator 64 is provided integrally with the casing 46 via a wall portion 62. An accumulator chamber 68 is formed at one end of a piston 66 constituting the accumulator 64. The extending rod 70 penetrates the wall 62 and enters the back chamber 72 of the expander piston 60. Piston 6
A spring 74 for pressing the piston 66 toward the back chamber 72 is disposed at the other end of the spring 6. An inlet valve 78 and an outlet valve 80 communicate with the back chamber 72 via a pipe 76, and a pump P is connected to the accumulator chamber 68 via a pipe 82.
The pump P supplies oil from the tank T under the action of the motor M. The motor M, the inlet valve 78 and the outlet valve 80
The controller 84 is connected to a control unit 86. As shown in FIG. 3, the control unit 86 determines the value of the wheel based on the output values of the wheel speed sensors 92 and 94 arranged corresponding to the disk plates 88 and 90 of the front wheel section 16 and the rear wheel section 18, respectively. A wheel speed calculating circuit 96 for calculating a rotational speed, a vehicle speed calculating circuit 98 for calculating and estimating a running speed of the vehicle body from the wheel speed, and a slip amount for obtaining a wheel slip amount from the running speed of the vehicle body and the wheel speed. A calculation circuit 100; a wheel acceleration / deceleration calculation circuit 102 for calculating the acceleration / deceleration of the wheel from the time change of the wheel speed; a slip amount threshold calculation circuit 104 for calculating a threshold value of the slip amount as a function of the wheel speed; A wheel acceleration / deceleration threshold value calculation circuit 106 that calculates a speed threshold value as a function of the wheel speed; and calculates the calculated slip amount and slip amount threshold value. It includes a first comparator circuit 108 to compare, and a second comparator circuit 110 for comparing the acceleration threshold and the computed acceleration. The comparison results of the first and second comparison circuits 108 and 110 are sent to the controller 84 to determine whether or not to generate a pulse. The controller 84 includes a pulse generation circuit 112 that generates a pulse train ,
Pal generated by the pulse generating decision circuit 112
Duty determination circuit 114 for determining the duty of the power train
And a driver 116 for driving the inlet valve 78 and the outlet valve 80 according to the pulse train whose duty ratio has been determined . On the other hand, the rear wheel modulator 36 has the same configuration as the above-described front wheel modulator 28, and a detailed description thereof will be omitted. Note that a configuration may be adopted in which control is performed by a single controller 84 without using the control unit 86. Next, the operation of the antilock braking device 20 configured as described above will be described in relation to the brake control method according to the present embodiment. At the time of normal braking, as shown in FIG. 2, the inlet valve 78 is opened and the outlet valve 80 is closed, and the oil projecting from the pump P is supplied from the inlet valve 78 to the pipeline 76. Is supplied to the back room 72 via the. For this reason, the expander piston 60 moves toward the output hydraulic chamber 54 (in the direction of arrow A) to open the cut valve 58. This allows input port 4
8 and the output port 50 communicate with each other, and the front wheel master cylinder 24 is urged by gripping the brake lever 22. The brake oil pressure generated by the front wheel master cylinder 24 is transmitted to the front wheel caliper cylinder 26 through the conduit 38, the input port 48, the output port 50, and the conduit 40, and a braking force is applied to the disk plate 88. . When the brake pedal 30 is depressed, a braking force is similarly applied to the disc plate 88 of the rear wheel portion 18. Here, the pump P moves from the accumulator chamber 6
8 is supplied with pressurized oil, the piston 66 retreats against the pressing force of the spring 74, and the accumulator chamber 6
8 is stored. Next, when the front wheel section 16 is about to enter a locked state, the control unit 8 performs antilock braking based on signals supplied from the wheel speed sensors 92 and 94 to the control unit 86.
A drive signal is supplied from 6 to the controller 84. That is, the wheel speed calculation circuit 9 of the control unit 86
6 calculates the rotation speed based on information indicating the rotation speeds of the front wheel portion 16 and the rear wheel portion 18 detected by the wheel speed sensors 92 and 94, and calculates the rotation speed of the vehicle body from the wheel speed information by the vehicle speed calculation circuit 98. The traveling speed is estimated. The slip amount calculation circuit 100 calculates the slip amount of the wheels from the running speed of the vehicle body and the wheel speeds of the front wheel section 16 and the rear wheel section 18, and the slip amount threshold calculation circuit 104 calculates the slip amount threshold value. Is calculated as a function of the actual wheel speed. Then, the calculated slip amount and the slip amount threshold are compared by the first comparison circuit 108. On the other hand, the wheel acceleration / deceleration calculation circuit 102 calculates the acceleration / deceleration of the wheel from the time change of the wheel speed, and the wheel acceleration / deceleration threshold calculation circuit 106 calculates the acceleration / deceleration threshold as a function of the actual wheel speed. The calculated acceleration / deceleration of the wheel and the acceleration / deceleration threshold are compared by the second comparison circuit 110. The comparison results from the first and second comparison circuits 108 and 110 are sent to the controller 84 to determine whether or not to generate a pulse. The occurrence of the pulse is determined, the pulse generation signal is delivered from the pulse generator determined <br/> Teikairo 112 constituting the controller 84 to the duty determination circuit 114. A wheel speed signal is sent from the wheel speed calculation circuit 96 to the duty determination circuit 114. When the pulse generation signal is sent, the pulse ON time (T-ON) and OFF time (T-ON) are output. OFF) is calculated as a function of the wheel speed (see FIG. 4). Then, a pulse ON / OFF signal is introduced from the duty determination circuit 114 to the driver 116, and the inlet valve 78 and the outlet valve 80 are driven. Therefore, the inlet valve 78 is closed, the outlet valve 80 is opened, the back chamber 72 communicates with the tank T, and the cut valve 58 is operated by the elastic force of the pressing spring 56 and the input hydraulic chamber. With the hydraulic pressure in 52, it retracts integrally with the expander piston 60. Accordingly, the cut valve 58 is seated, the input port 48 and the output port 50 are shut off, and the volume of the output hydraulic chamber 54 increases due to the movement of the expander piston 60, and the brake hydraulic pressure supplied to the caliper cylinder 26 decreases. . Further, the inlet valve 78 is opened, the outlet valve 80 is closed, and the expander piston 60 is moved in the direction of arrow A to increase the brake oil pressure. The anti-lock braking is performed by repeatedly performing the pressure reduction and the pressure increase. Although the anti-lock braking of the front wheel portion 16 has been described above, the anti-lock braking of the rear wheel portion 18 is similarly performed. In this case, in this embodiment, the slip amount threshold and the acceleration / deceleration threshold as antilock braking parameters are changed according to the magnitude of the wheel speed. In particular,
The wheel speed is divided into two or more sections based on a predetermined speed, and the slip amount threshold and the acceleration / deceleration threshold are changed according to the section to which the actual wheel speed belongs. Then, the first and second comparison circuits 108 and 110 compare the slip amount threshold value and the acceleration / deceleration threshold value as the changed parameters with the calculated slip amount and acceleration / deceleration value, and compare the comparison result (control signal) with the controller 84. Is output to Further, when the pulse generation is determined based on the comparison result, a wheel speed signal is sent to the duty determination circuit 114 together with the pulse generation signal, and the ON time and OFF time of the pulse are determined according to the magnitude of the wheel speed. Is calculated. As described above, since various antilock braking parameters are changed in accordance with the actual wheel speed, the wheel speed changes per unit time as in the case where the rotation of the wheel is slow, that is, at low speed. When the (information amount) is small, the antilock braking can be performed in accordance with the small amount of information, and the effect that the reliable and highly accurate antilock braking becomes possible is obtained. As a result, continuity of antilock braking can be ensured, and stability of the vehicle body can be improved. Further, when the anti-lock braking is started while the motorcycle 10 is cornering, the bank angle varies depending on the wheel speed of the motorcycle 10.
That is, as the wheel speed increases, the bank angle can be increased (deeper). Therefore, by changing the anti-lock braking start slip ratio as a parameter according to the magnitude of the wheel speed, it is possible to effectively cope with such a change in the characteristics of the motorcycle 10. In this embodiment, the anti-lock braking parameters that change according to the magnitude of the wheel speed include:
The slip amount threshold, acceleration / deceleration threshold, and anti-lock braking start slip ratio are listed, but are not limited thereto, and all necessary for anti-lock braking such as a pressure increase / decrease signal, a holding signal, or an anti-lock braking start position. Can be used as a change parameter. As described above, in the brake control method according to the present invention, the control amount required for the antilock braking is calculated based on the wheel speed, and the control amount is calculated according to the magnitude of the wheel speed. Anti-lock braking parameters changed,
Further, a control signal is output based on the changed parameter and the calculated control amount. For this reason, even if the information amount changes according to the magnitude of the wheel speed, the antilock braking can be accurately performed according to the information amount, and the effective antilock braking according to the change in the vehicle body characteristics. Is performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a motorcycle equipped with an anti-lock braking device for implementing a brake control method according to the present invention. FIG. 2 is a schematic configuration diagram of the antilock braking device. FIG. 3 is a block diagram of a control unit and a controller constituting the antilock braking device. FIG. 4 is an explanatory diagram of pulses generated in the antilock braking device. DESCRIPTION OF SYMBOLS 10 ... motorcycle 16 ... front wheel section 18 ... rear wheel section 20 ... anti-lock braking device 28 ... front wheel modulator 36 ... rear wheel modulator 84 ... controller 86 ... control units 92 and 94 ... wheel speed sensor 96 ... wheel speed calculation circuit 98 ... body speed calculation circuit 100 ... slip amount calculation circuit 102 ... wheel acceleration / deceleration calculation circuit 104 ... slip amount threshold value calculation circuit 106 ... wheel acceleration / deceleration threshold value calculation circuits 108 and 110 ... comparison circuit 112 ... pulse generation decision Circuit 114: Duty determination circuit

Continuation of the front page (56) References JP-A-63-38073 (JP, A) JP-A-62-218259 (JP, A) JP-A-63-141865 (JP, A) JP-A-3-182866 (JP) JP-A-2-70567 (JP, A) JP-A-64-63462 (JP, A) JP-A-1-314655 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B60T 8/58

Claims (1)

(57) [Claim 1] A brake control method for a motorcycle which performs anti-lock braking by controlling a braking force of a wheel, comprising: a step of detecting a wheel speed of the wheel; A step of obtaining a slip amount and an acceleration / deceleration based on the performed wheel speed; and a step of generating a pulse train when it is determined that antilock control is necessary based on the slip amount and the acceleration / deceleration. Due to the wheel speed
And directly change the duty of the pulse train .
And a step of performing anti-lock braking based on the pulse train whose duty has been changed .