摘要:
A braking force distribution control device for an automotive vehicle is designed to make it possible to initiate a braking force distribution control as rapidly as possible upon rapid braking operation while at the same time being capable of preventing a malfunction of the braking force distribution control even when one of hydraulic pressure lines fails. The braking force distribution control establishes a predetermined relationship between the wheel cylinder pressure of a front wheel and a wheel cylinder pressure of a rear wheel on the basis of a comparison between the wheel speeds of the front and rear wheels. The braking force distribution control is initiated when the decelerations of all the wheels exceed a set value.
摘要:
The present invention is directed to an apparatus for determining a state of braking operation of a vehicle. Wheel speed sensors are provided for detecting wheel speeds of a front wheel and a rear wheel. A wheel speed difference is calculated between the wheel speed of the front wheel and the wheel speed of the rear wheel detected by the wheel speed sensors. A braking operation detection device is provided for detecting an operation of a brake pedal. Based upon the calculated wheel speed difference and the operation of the brake pedal detected by the braking operation detection device, it is determined whether the brake pedal was rapidly depressed. In accordance with this result, and in response to the wheel speeds detected by the wheel speed sensors, the braking force applied to the front wheel can be adjusted in a predetermined relationship with the braking force applied to the rear wheel.
摘要:
An anti-skid control system for an automotive vehicle is provided with braking condition detectors for detecting at least a running condition of the vehicle in braking operation and producing a detected signal corresponding to the running condition. The detected signal is compared with a reference value to produce a braking condition signal. In response to the braking condition signal, selectively provided is one control mode of a simultaneous control mode for controlling simultaneously a braking force applied to both of a pair of right and left road wheels and an independent control mode for controlling independently a braking force applied to each of the right and left road wheels. Then, the braking force applied to the right and left road wheels is controlled in accordance with the control mode.
摘要:
The invention is directed to an arrangement for controlling a braking force applied to each of front and rear road wheels of a vehicle depending upon a braking condition, with a hydraulic braking pressure supplied to each of the wheel brake cylinders through an actuator. The actuator is controlled by a braking force controller into which output signals of wheel speed sensors are fed. On the basis of the wheel speeds detected by the sensors, an estimated vehicle speed is calculated, and then a varying rate of the estimated vehicle speed is calculated. Furthermore, a wheel speed differential between the front and rear road wheels (or, a wheel slip rate differential therebetween) is calculated. Only when the wheel speed differential (or, the wheel slip rate differential) exceeds a predetermined value, the varying rate of the estimated vehicle speed is compared with a standard rate to estimate a coefficient of friction of the road surface. Then, the hydraulic braking pressure applied to each of the wheel brake cylinders is controlled by the braking force controller in accordance with the estimated coefficient of friction and in response to the each wheel speed.
摘要:
The present invention is directed to an anti-skid control system wherein at least a pressure decrease mode for decreasing a hydraulic braking pressure and a pulse pressure increase mode for intermittently increasing the hydraulic braking pressure, with a pressure increasing signal provided in accordance with the braking condition of a vehicle. Peaks of the wheel speed in the pulse pressure increase mode are detected continuously on the basis of a variation of a wheel acceleration relative to a vehicle acceleration. Then, the time when each peak of the wheel speed was detected is set as a rise timing of the pressure increasing signal in the pulse pressure increase mode, and a time period for which the pressure increasing signal outputs is adjusted, on the basis of a variation of the rotating condition of the wheel at the time when the peak of the wheel speed was detected. The time period for which the pressure increasing signal outputs may be set on the basis of a ratio of a first integrated value of a difference obtained by subtracting the vehicle acceleration from the wheel acceleration, to a second integrated value of a difference obtained by subtracting the wheel acceleration from the vehicle acceleration.
摘要:
The present invention is directed to an anti-skid control system which includes a pressure generator to supply a hydraulic braking pressure into a wheel brake cylinder through an actuator. A return passage is provided for communicating the wheel brake cylinder with the actuator. A pressure pump is disposed in the return passage, and a reservoir is disposed in the return passage at the inlet port's side of the pump. The reservoir stores the brake fluid discharged from the wheel brake cylinder through the actuator to decrease the wheel cylinder pressure. The actuator blocks the communication between the pressure generator and the wheel brake cylinder, and then the pump discharges the brake fluid stored in the reservoir into the return passage thereby to gradually increase the wheel cylinder pressure. A first fluid estimating device estimates a first amount of brake fluid supplied from the pressure generator into a hydraulic circuit disposed downstream of the actuator and including the wheel brake cylinder and the reservoir. And, a fluid supply allowing device allows the actuator to communicate the pressure generator with the wheel brake cylinder, when the first amount of brake fluid is smaller than a first predetermined amount.
摘要:
A fluid pressure source apparatus includes a pump, an accumulator for receiving pressure from the pump, a pressure switch for detecting the pressure in the accumulator, an electric motor for driving the pump, and a motor control device for driving the motor when the pressure switch detects a low pressure. A current detecting device detects a motor current value of the motor and a control unit determines whether the accumulator or the motor is experiencing an abnormality based on the motor current value. The control unit determines whether the motor current value occurring during a first set time following the start of driving of the motor is greater than a first set value. If the motor current value is not greater than the first set value, the control unit determines that the current detecting device is experiencing an abnormality. If there is no such abnormality information, the control unit compares the motor current value with predetermined values. If the motor current value continues to be less than a lower limit value for at least a predetermined length of time, the control unit determines that there is a low pressure abnormality. If the motor current value continues to be greater than an upper limit value for at least a predetermined length of time, the control unit determines that there is a motor lock abnormality.
摘要:
An antiskid device according to this invention controls the hydraulic pressure to vehicle brakes based on the rotational speed of the wheel having the smallest coefficient of friction until a standard vehicle velocity becomes less than a predetermined velocity. Further, the antiskid device controls the hydraulic pressure to the brakes based on the speed of each wheel if the standard vehicle velocity becomes less than the predetermined velocity. Accordingly, directional stabilization of the vehicle is maintained when the vehicle runs at high speed, and at low speed, the braking range for stopping the vehicle is mainimized by utilizing the braking force more efficiently.
摘要:
An anti-skid brake system for a wheeled vehicle including speed sensors for detecting each speed of road wheels of the vehicle and for producing an electric signal indicative of the detected speed of the road wheels, an electronic control apparatus arranged to be applied with the electric signal from the speed sensors for producing a control signal in accordance with conditions of a travel road of the vehicle in braking operation, and an electrically operated actuator arranged to be activated under control of the control apparatus for controlling a hydraulic braking pressure applied to each brake cylinder of the road wheels in response to the control signal, wherein an acceleration speed of the road wheels is calculated in response to the electric signal from the speed sensors, a stepped portion on the travel road is detected by determination of the fact that the detected speed of the road wheels becomes higher than a predetermined reference speed within a predetermined time immediately after activation of the actuator and that the calculated acceleration speed of the road wheels becomes smaller than a predetermined negative value and larger than a predetermined positive value within the predetermined time, and the actuator is deactivated upon detection of the stepped portion on the travel road.
摘要:
When a vehicle stops, a brake control unit maintains a braking force applied on a wheel by a braking-force application unit for maintaining a halted state. In this state, if a driver depresses the accelerator pedal to execute starting of the vehicle, the braking force is gradually decreased, and the vehicle starts at a speed that accords with a degree of accelerator opening and a gradient of a road on which the vehicle is stopped. When a movement direction at this time is the same as a movement direction intended by the driver, the braking force is decreased to zero for smooth starting. When the movement direction is opposite to the intended movement direction, the braking force is increased to control the movement in the opposite direction, such that the movement changes from the opposite direction to the same direction, and finally, smooth starting in the desired direction is executed.