Toyota Jidosha Kabushiki Kaisha

Advics Co., Ltd.

Aisin Seiki Kabushiki Kaisha

Chiaki Hamada

Hiroyuki Ichikawa

Shinsuke Sakane

Akifumi Doura

Satoru Fukushima

Kaoru Ohashi

Hiroshi Kawakami

Yutaka Hirano

Masanobu Yamaguchi

Tomohiro Kato

Zensaku Murakami

Michio Akiyoshi

A braking control device for a vehicle executes braking force distribution (BFD) biased to front wheel in a manner compatible with Anti-skid control. In BFD control, braking force on rear wheels is held at a holding braking force and braking force on the front wheels is incremented beyond braking force requested by a braking action of a driver. After the starting of BFD control, further increase in the braking action is reflected in the front wheel braking force. Upon starting anti-skid control for either of the wheels during the execution of BFD control, an increment of the front wheel braking forces to be requested by BFD control is gradually decreased. Simultaneously, the holding of the rear braking force is released so as to compensate for the shortage of braking force on the front wheel. The gradual decrease of the braking force increment prevents a conflict of BFD and Anti-skid control.

Vehicle braking control device for braking force distribution

The similarity groups of the pressure differential&#x2014;current characteristics of solenoid valves are measured in advance, and the measurement results are used to select the solenoid valves to be used for first to fourth pressure increase control valves. Only solenoid valves in the same region in terms of their similarity group of the pressure differential&#x2014;current characteristics are used for the first to fourth pressure increase control valves. A board on which the first to fourth control valves are mounted is provided with a mark unit that indicates the similarity group of the pressure differential&#x2014;current characteristics of the first to forth pressure increase control valves. The mark unit includes a resistor. A brake ECU uses the resistance value of the resistor to identify the similarity group of the pressure differential&#x2014;current characteristics of the first to fourth pressure increase control valves.

Vehicle brake fluid pressure control device

A braking control device for a vehicle executes braking force distribution (BFD) biased to the front wheels, taking into account auxiliary braking control such as braking assist control (BAS) executed when an abrupt or full braking action is performed by the driver. In BFD control a braking force on the rear wheels is held at a holding braking force and a braking force on the front wheels is incremented beyond a braking force requested by a braking action of the driver. After the starting of BFD control, further increase in the braking action is reflected in the braking force of the front wheels. When auxiliary braking control is executed, the holding braking force on the rear wheels and the increment of the braking force on the front wheels are determined based upon a demand of the auxiliary braking action as well as the braking action amount by the driver.

A braking control device of a vehicle starts executing braking force distribution (BFD) biased to front wheels for avoiding the locking of rear wheels prior to the front wheel at appropriate time by reducing errors of a judgment of the starting of the control. Usually, the BFD control is started in response to the increase of a master cylinder pressure, assuming that the rear wheel braking pressure is equally increased. When a fast braking action occurs, the delay of the pressure variation of the rear wheel braking pressure relative to the master cylinder is conspicuous because the responsibility of a master cylinder pressure to the braking action is too fast. Thus, Upon a fast braking action, a judgment of starting of BFD control is made based upon a value involved with rear wheel braking force, such as an estimation value of the rear wheel braking pressure, having a slower responsibility to the braking action than the master cylinder pressure, and thereby preventing a premature start of the BFD control due to the delay of the rear wheel braking pressure. When a deceleration signal is used for the judgment of starting of BFD control, the signal is passed through a low-pass filter having a rather higher cut-off frequency on a fast braking action, in order to improve the responsibility of the signal to the braking action.

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.

Anti-skid control system for rear wheels

The invention is directed to an arrangement for controlling a braking force applied to each of driven wheels and non-driven wheels depending upon a braking condition, with a hydraulic braking pressure supplied to each of wheel brake cylinders through an actuator. The actuator is controlled by the braking force controller into which output signals of wheel speed sensors are fed. The braking force controller is arranged to control the hydraulic braking pressure supplied to each of the wheel brake cylinders. When one driven wheel is under the anti-skid control, it is determined whether a difference speed between the driven wheels is greater than a predetermined value. If it is determined that the difference speed is greater than the predetermined value, the actuator is actuated to restrain the hydraulic braking pressure from being supplied to the wheel brake cylinder operatively connected to the other driven wheel, e.g., to hold the hydraulic braking pressure supplied to the wheel brake cylinder, or to reduce a rate of increase of the hydraulic braking pressure.

Anti-skid control system for driven wheels

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.

Anti-skid brake system for wheeled vehicle

Control system for controlling an anti-lock braking system having a brake for a wheel of a motor vehicle, wherein a skidding or locking condition of the wheel is detected by a detector based on a running condition of the vehicle and a rotating condition of the wheel, and a slip ratio of the vehicle is maintained within an optimum range by a pressure-regulating device, by increasing, decreasing and holding a brake fluid pressure applied to the brake, in response to the detected locking condition of the wheel. A predetermined pressure-decrease time during which the fluid pressure is decreased is measured by a measuring device, and a deceleration rate of a rotating speed of the wheel when the pressure-decrease time has elapsed is detected by a detecting device. A device is provided for determining an extension time during which the fluid pressure is further decreased, such that the extension time increases with the detected deceleration rate of the wheel. The pressure-regulating device is activated to further decrease the fluid pressure for the determined extension time.

Vehicle braking system for drive wheels, having means for determining a

Provided is a so-called active suspension controller for a vehicle especially effective during turning. The controller comprises: an actuator provided between the body and every wheel of the vehicle; sensors for a turning condition of the vehicle, here the turning condition including a steering angle, vehicle speed, yaw rate and others; and a control apparatus responsive to the sensed turning condition for driving the actuators in order to control the allotment ratio between the front and the rear axles of the load shift between the right and the left wheels. The allotted load shift realizes stable turning under various circumstances.

Growing community of inventors

Mishima, Japan

Chiaki Hamada