摘要:
An anti-skid control system for a motor vehicle, includes a brake fluid pressure buildup-control mode and a brake fluid pressure reduction mode, each of which occur cyclically. In each buildup-control mode, a control valve is repetitively opened and closed so that brake fluid pressure buildup and holding operations are performed alternately. The time period of each buildup-control mode is from a high peak of a wheel speed signal until a point of intersection between a reference velocity V.sub.W0 and the wheel speed V.sub.W. The reference velocity V.sub.W0 has an initial point Q positioned under the high peak V.sub.HP of the wheel speed V.sub.W by a velocity value .DELTA.V and extending straight at a gradient .theta.. The speed value .DELTA.V, the gradient .theta., and an initial pressure buildup time T.sub.P, in each building-control mode, are determined in accordance with the wheel acceleration in the preceding wheel acceleration, i.e., coefficient of friction of the road surface.
摘要:
An anti-skid brake control system for a motor vehicle comprises: a wheel speed sensor which is provided for each wheel of the vehicle and generates a pulse signal having a pulse cycle which corresponds to a revolutional speed of each wheel; a pulse cycle measuring circuit for detecting the cycle of the pulses of the pulse signal from each wheel speed sensor; and, a discriminator for discriminating an actual acceleration or deceleration state. The actual acceleration or deceleration state is discriminated in accordance with whether or not the period of the acceleration or deceleration state is longer than a predetermined time. The acceleration or deceleration state is calculated from the wheel speed data detected by the pulse cycle measuring circuit, and the system is controlled on the basis of the result of the discrimination by the discriminator.
摘要:
In an anti-skid control system for a motor vehicle, brake fluid pressure reduction-control mode and brake fluid pressure buildup-control mode occurs cyclically; in the reduction-control mode, reduction of the brake fluid pressure is started on the basis of detection of an abrupt drop in wheel speed which occurs when the wheel is braked; and in buildup-control mode, a valve is repetitively opened and closed so that brake fluid pressure buildup and holding operations are performed alternatley and repetitively, whereby the brake fluid pressure is caused to build up gradually. The length of time period for the first buildup operation in the buildup-control mode is determined on the basis of variation in the wheel speed occurring between a low peak point and a high peak point; and the length of time period for at least one of each pressure holding operation and each of the second and succeeding pressure buildup operations in the abovementioned buildup-control mode, is determined on the basis of variation in the wheel speed occurring immediately before the pressure holding or buildup operation is started.
摘要:
An anti-skid control system for motor vehicles is provided wherein the higher one of the lefthand and righthand rear wheels is selected as a first computed speed; the lower one of the above two wheel speeds is selected as a second computed speed; the lower one of the first computed speed and lefthand front wheel speed is selected as a third computed speed; the lower one of the first computed speed and righthand front wheel speed is selected as a fourth computed speed; and a reference speed is set up on the basis of the first computed speed in such a manner that it is lower than the first computed speed by a predetermined amount and follows the first computed speed with such a speed difference. Reduction of brake pressure which has been increased, is started on the basis of the third or fourth computed speed; and in the case where the second computed speed being decelerated, goes below the reference speed, the reduction of the brake hydraulic pressure is stopped at time when the second computed speed which is now being increased as the result of the brake pressure reduction goes above the reference speed, and thereupon buildup of the brake pressure is started.
摘要:
An anti-skid control system for motor vehicles is provided wherein when the time period from when the wheel velocity being decreased reaches a second reference velocity to a low peak of the wheel velocity at which the reduction of the brake pressure is to be stopped, is longer than a predetermined time period, the reduction of the brake pressure is continued until the wheel velocity is increased up to a first reference velocity which is higher than the second reference velocity. In this way, even if the wheel velocity drops sharply because the coefficient of friction of the road surface suddenly changes from high to low, the wheel velocity recovers so that the wheels of the motor vehicle are prevented from locking early.
摘要:
An anti-skid control system for motor vehicles is provided wherein a computed wheel speed Vv is set up on the basis of the highest one of the wheel speeds of the motor vehicle; a first reference speed VT1 and a second reference speed VT2 are set up which are lower than and follow the computed vehicle speed Vv either with a first and second predetermined speed difference respectively or with a first and a second predetermined ratio respectively, the first reference speed VT1 being higher than the second reference speed VT2 (VT1>VT2); in the case where the wheel speed continues decreasing with a deceleration lower than a predetermined threshold level of deceleration, reduction of brake pressure is started at a point of time when a predetermined time period T1 elapsed from a point of time when the wheel speed reached the level of the second reference speed VT2; and the reduction of the brake pressure is stopped at a point of time when the wheel speed was increased up to the level of the first reference speed VT1 as a result of the reduction of the brake pressure.
摘要:
A traction control method/apparatus for motor vehicles is arranged such that at an initial stage of the starting or accelerating operation of the motor vehicle where a large amount of slip of the driving wheel tends to be caused, a braking force is sufficiently applied to the driving wheel to restrain the slip thereof; and after the engine output is adjusted through accelerator or throttle control which is performed simultaneously with the application of the braking force, the procedure for controlling the brake hydraulic pressure is changed to eliminate the difference between the lefthand and righthand driving wheel speeds.
摘要:
A wheel lock prevention system prevents locking of wheels in a vehicle including a front axle having right and left front wheels, a first rear axle having right and left driving wheels, and a second rear axle having right and left follower wheels. A control part determines that locking or skidding of particular wheels may occur based on signals from sensors. In response, the control part transmits a signal to apply the appropriate brake force to the appropriate wheels.
摘要:
An anti-lock control apparatus of this invention has modulators each of which is disposed at a point between said master cylinder and each set of front and rear brakes. Each modulator has a stepped piston in its cylinder. In the cylinder, are formed a front output fluid chamber and a rear output fluid chamber both of which follow the master cylinder. The front output fluid chamber is connected to the front brake, while the rear output fluid chamber is connected to the rear brake. The front output fluid chamber normally communicates with the rear output fluid chamber and, during anti-lock operation, the communication between the front output fluid chamber and the rear output fluid chamber is cut off by a cut-off valve portion. Thus, the fluid pressure of the rear brake can be maintained at the fluid pressure in the cut-off state.
摘要:
An antiskid control system wherein the conventional method of performing an opening/closing change-over operation by a pulse train signal on a electromagnetic valve for increasing hydraulic braking pressure at a variable rate of increase is not employed but the pressure increasing rate is arranged to be variable by the use of an electromagnetic valve having some throttled position.