Nippondenso Co., Ltd.

Advics Co., Ltd.

Toyota Jidosha Kabushiki Kaisha

Denso Corporation

Shoichi Masaki

Takashi Watanabe

Moriharu Sakai

Tadaaki Tsuno

Satoshi Hirano

Naohiko Tsuru

Ken Asami

Kazunori Sakai

Yutaka Okuda

Hiromi Maehata

A vehicle emergency brake system has a second brake for braking a vehicle by increasing the frictional resistance with the road surface, a millimeter wave radar for detecting any obstacle in an advancing direction, a pedal speed sensor for detecting the step-in speed of a brake pedal for actuating a first brake, and a controller for actuating the second brake. If hard braking by the first brake is detected by the pedal speed sensor, the controller determines whether the vehicle is going to crash into an obstacle detected by the radar. If a determination is made that it will collide, the second brake is actuated. Thus, it is possible to reliably actuate the second brake in an emergency.

Emergency braking apparatus for vehicle

A vehicle movement stabilizing device is provided which in effectively functioning braking, acceleration and turning movement during travel of the vehicle by activating the frictional force adding device, reliably controls the start and end of the operation of the frictional force adding device and prevents repetition of unnecessary operations. The vehicle movement stabilizing device is provided with frictional force adding device for increasing the frictional force of the wheels to the road surface by scattering particles and a controller. The controller is structured to start the operation of the frictional force adding device when it detects the operation start conditions based on signals from wheel speed sensors, a hydraulic pressure sensor and a step-in force sensor during braking, and to stop its operation if signals indicating disappearance of the state are detected, thereby preventing repetition of unnecessary operations.

Vehicle movement stabilizing device

The aim is to stably control the lateral movement of a vehicle even on a road where the frictional coefficient is extremely small, such as on a frozen road, thereby improving the turnability and travelling stability. The device includes a frictional force adding means for increasing the frictional force of wheels to a road surface by scattering particulates and a controller which calculates the target lateral movement value and the actual lateral movement value based on the signals from wheel speed sensors, a steering angle sensor and a yaw rate sensor and actuates the right or left frictional force adding means according to the difference between these two values to increase the frictional force, thereby stabilizing the lateral movement.

Vehicle lateral movement stabilizing device

An apparatus for detecting a condition of a road surface includes a vehicle wheel speed detecting device for outputting a vehicle wheel speed signal representing a speed of a wheel of a vehicle. A vehicle wheel speed summating device operates for summating variations in the vehicle wheel speed represented by the vehicle wheel speed signal during every time period corresponding to one revolution of the vehicle wheel, and for generating a summation value representing a result of the summating. A road-surface condition detecting device for detecting a road-surface condition on the basis of a difference between a current summation value and a previous summation value generated by the vehicle wheel speed summating device.

Apparatus for detecting condition of road surface

A descending grade condition detecting system which can accurately detect a descending grade such as a snow-packed road or the like where slippage is likely determines whether permission has been granted to perform descending grade determination. If so, it determines whether established vehicle body deceleration is 0.3 G or less. If so, the system determines whether a road surface at each of the wheels is low .mu. corresponding to a snow-packed road or the like. If estimated vehicle body deceleration is small and of comparatively high .mu., descending grade condition flags KF are set for the respective wheels for which determination thereof has been made to indicate that a condition of a road being traveled is a condition of a low .mu. descending grade of a snow-packed road or the like.

Descending grade condition detecting apparatus

The wheel speed of each wheel of a vehicle is calculated based on wheel speed signals from wheel speed sensors. The wheel acceleration of each wheel is calculated based on the wheel speed. High frequency components of the wheel acceleration of each wheel are filtered using a high-pass filter to obtain the frequency components of the wheel acceleration which are due only to the road surface condition. Then, a variance of the filtered wheel acceleration is calculated, and a bad road condition determination is executed using the calculated variance. Anti-skid control is carried out based on the bad road condition determination result to provide improved braking control in off-road conditions.

Anti-skid controller having accurate road surface detection capabilities

A brake pressure control device is capable of realizing reduction in a braking distance of a vehicle by promoting control in decreasing brake pressure applied on wheel braking force generating members such as wheel cylinders or a response function in increasing the brake pressure applied on the wheel braking force generating members in generating braking force on wheels. When there is a pressure difference between wheel cylinders, a reservoir control valve is brought into a blocking state and two control valves are brought into a communicating state by which pressure of the brake fluid is shifted from a wheel cylinder on high pressure side to a wheel cylinder on the low pressure side, by which the pressure of the wheel cylinder on the high pressure side can be decreased by only shifting the brake fluid between the wheel cylinders without making the brake fluid flow into a reservoir and accordingly, a relative time by which the reservoir becomes full is retarded and the response function in increasing the pressure of the brake fluid can be enhanced by that amount.

Brake pressure controlling apparatus

In an anti-skid control system for a motor vehicle there is provided a fail-safe control system for providing a compensation for a proper vehicle braking operation against the occurrence of failure of a hydraulic pressure control valve. The fail-safe control system includes a device for monitoring a control signal for controlling the operation of the control valve so that the hydraulic pressure applied to a wheel braking cylinder is regulated for preventing a wheel of the vehicle from skidding. The monitoring device detects the occurrence of failure of the control valve when the control signal indicative of one of the operation modes of the control valve is continuously generated more than a predetermined time period. In response to the detection, the fail-safe control system switches a directional control valve to the passage-opening condition so that the hydraulic pressure from a master cylinder can directly be applied to the wheel braking cylinder, thereby enabling the braking operation to be controlled by a vehicle driver.

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Asahi-machi, Japan

Shoichi Masaki