Aisin Seiki Kabushiki Kaisha

Advics Co., Ltd.

Other

Toyota Jidosha Kabushiki Kaisha

Aisin Seiki K.k.

Adivics Co., Ltd.

Shinsuke Sakane

Hiroyuki Ichikawa

Kazutaka Kuwana

Tsuyoshi Yoshida

Toshihisa Kato

Yuzo Imoto

Hiroaki Aizawa

Satoshi Yokoyama

Chiaki Hamada

Masashi Kishimoto

Satoru Fukushima

Nobuyasu Nakanishi

Kenji Tozu

Masanobu Fukami

Tatsuo Sugitani

Satoshi Yamada

Katsuo Ohbai

Ken Asami

Hiroshi Nakashima

Masaru Kamikado

Yasuhiro Abe

Yoshiaki Tsuchiya

Tetsuya Miyachi

Yoshifumi Misaka

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.

Automatic braking device for controlling movement of vehicle in unintended direction of the driver with target brake decreasing control

A creep drive control device according to the invention sets a target creep vehicle speed when a driver has neither one of an acceleration intention or a stop maintenance intention. An engine output is increased (or decreased) by a vehicle speed increase processing (or a vehicle speed decrease processing), or a braking force is decreased (or increased), and an actual vehicle speed is controlled so as to be equal to the target creep vehicle speed or a value in the proximity thereof. The target creep vehicle speed, and respective engine output and braking force increase amounts and decrease amounts are corrected and set in accordance with driving conditions, road surface conditions and driver operations.

Creep drive control device for driving vehicle at creep speed

Automatic brake device for controlling movement of vehicle in direction opposite to intended direction of movement of driver

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.

Apparatus for determining a state of braking operation

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.

Brake force distribution control device for automotive vehicles

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.

Anti-skid control system for an automotive vehicle

An anti-skid control system includes a hydraulic pressure generator for generating hydraulic brake pressure, hydraulic pressure control valves which control the brake hydraulic pressure of the wheel cylinders, wheel speed sensors for detecting the rotational speed of the wheels, and a controller for controlling the hydraulic pressure control valves to decompress or pulse-boost the brake hydraulic pressure in the wheel cylinders based on the output signal of the wheel speed sensors. A brake pedal depression amount detecting device detects the amount of depression of the brake pedal. The controller includes a road surface change judging device for judging that the road surface has shifted from a surface having a low coefficient of friction to a surface having a high coefficient of friction when a continuous run pulse number or a continuous run time of the pulse boost control exceeds a preset value. A duty ratio changing device changes the duty ratio of the pulse boost control to increase the rate of boost time when the road surface change judging device has judged a shift from a road surface having a low coefficient of friction to a road surface having a high coefficient of friction. A pulse boost executing device controls the hydraulic pressure control valve to pulse-boost the brake hydraulic pressure of the wheel cylinders based on the duty ratio changed by the duty ratio changing device, and a preset value changing device changes the preset value based on the output signal of the depression amount detecting device.

Anti-skid control system

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.

Fluid pressure source apparatus

A fluid pressure source apparatus has a pump, an accumulator, a pressure switch, and a control device for turning on and off the pump in accordance with the signal from the pressure switch. The control device has a pressure increase control unit. When the pressure detection signal of the pressure switch indicates a high pressure, the pressure increase control unit estimates a pressure reduction N resulting from a fluid pressure consumption by a fluid pressure circuit. If the estimated amount of pressure reduction N exceeds a set value KN=KN1, KN2, the pressure increase control unit drives the pump for a set time KT=KT1, KT2, thereby ensuring a predetermined range of accumulator pressure despite a possible failure of the pressure switch or sensor.

Fluid pressure source apparatus for providing adequate accumulator

An anti-skid control device includes wheel brake cylinders, a hydraulic pressure generator, and hydraulic pressure control valves for controlling the hydraulic braking pressure in each wheel brake cylinder. The wheel speeds of the plurality of wheels are sensed by respective wheel speed sensors, and the vehicle speed is calculated on the basis of the wheel speeds. A right vehicle speed is calculated on the basis of the wheel speed of one of the wheels on the right hand side of the vehicle and a left vehicle speed is calculated on the basis of the wheel speed of one of the wheels on the left hand side of the vehicle. A vehicle speed differential between the right vehicle speed and the left vehicle speed is calculated. A vehicle lateral acceleration is then calculated from the vehicle speed differential and the vehicle speed. When the vehicle lateral acceleration exceeds a first predetermined value before an anti-skid control starts operating during depression of the brake pedal, an increase rate of the hydraulic braking pressure in an inside rear wheel is reduced.

Anti-skid control device

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.

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.

Anti-skid control based upon estimated coefficient of friction

An anti-skid apparatus for installation in a vehicle braking system includes an electrically operated actuator arranged to control hydraulic brake pressure applied to each wheel brake cylinder of road wheels of the vehicle and an electronic control device for applying an electric control signal to the actuator in response to electric signals indicative of each rotational speed of the road wheels so that the actuator is operated to decrease or increase the brake pressure when the rotational speed of the road wheels in braking operation becomes lower than a reference speed the value of which is defined on a basis of a travel, speed of the vehicle. The electronic control device is designed to detect a step on a travel road of the vehicle in braking operation and to compare the rotational speed of the road wheels with a subtracted value of the reference speed when the step on the travel road has been detected within a predetermined time thereby to maintain the actuator in its deactivated condition when the rotational speed of the road wheels is larger than the subtracted value of the reference speed.

Anti-skid apparatus for automotive vehicle

The invention is directed to an arrangement for controlling a braking force applied to each of 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. The hydraulic braking pressure applied to each of the wheel brake cylinders is controlled by the braking force controller in accordance with each wheel speed. And, it is determined whether the vehicle is turning or not. If the vehicle is turning, the hydraulic braking pressure in a wheel brake cylinder operatively connected to one of the rear road wheels positioned at the outer side is controlled such that a decreasing operation of the pressure is restrained for at least a predetermined time period.

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Toyota, Japan

Shinsuke Sakane