Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Jun Mihara

Kenji Tozu

Takayuki Itoh

Norio Yamazaki

Shoji Inagaki

Toshiaki Hamada

Hiroshi Nakashima

Noriaki Hattori

Masaki Yamamoto

Yoshiharu Nishizawa

Shingo Sugiura

Yoshiyuki Yasui

Masanobu Fukami

Hiromu Kuromitsu

Seiichi Kojima

Hitoshi Terada

Akio Sakai

A vehicle motion control system for a vehicle for maintaining stability of a vehicle when the vehicle is in motion includes braking device for applying a braking force to each wheel of the vehicle. The system includes a lateral acceleration sensor for sensing a lateral acceleration of the vehicle and a yaw rate sensor for sensing a yaw rate of the vehicle. A vehicle slip angular velocity is calculated on the basis of output signals of the lateral acceleration sensor and the yaw rate sensor and then a vehicle motion condition is determined on the basis of the vehicle slip angular velocity. The braking device is actuated to apply a braking force to at least one of the wheels on the basis of the vehicle motion condition and irrespective of depression of the brake pedal in order to maintain the stability of the vehicle in motion. An abnormal condition of at least one of the lateral acceleration sensor and the yaw rate sensor is determined on the basis of the vehicle slip angular velocity.

Vehicle motion control system

The present invention is directed to a vehicle motion control system for maintaining vehicle stability, even in the case where the vehicle is tilted when the vehicle is in turning motion, wherein a braking force control unit is provided for controlling a braking force applied to each of front and rear wheels of the vehicle. The system includes a tilt detection unit which detects a tilt of a normal axis of the vehicle to its vertical axis, and a turn determination unit which determines a turning condition of the vehicle including a turning direction thereof. A yaw moment control unit is provided for controlling the braking force controlling unit to produce a yaw moment in a direction opposite to the turning direction of the vehicle in response to the tilt detected by the tilt detection unit when the turn determination unit determines that the vehicle is turning.

A wheel brake pressure controlling system includes a brake pressure operating circuit for selectively supplying to a wheel brake a primary pressure generated by a vacuum booster in response to the depression of a brake pedal and a secondary pressure generated by a hydraulic pressure pump which is driven by an electric motor, a microcomputer for estimating a turning of vehicle, determining if a turning of the vehicle is in a over- or under-steer region, and for determining a wheel brake, the pressure of which is to be intensified if the turning of the vehicle lies in the over- or under-steer region, and an output controller for supplying the secondary pressure to the wheel brake which has been thus determined, through the brake pressure operating circuit. The microcomputer determines if the turning of a vehicle occurs in a reference region located outside the over- or under-steer region, and whenever the turning of the vehicle occurs in the reference region, drives the second source of pressure for generating the secondary pressure, determines a wheel brake which is to be intensified, and automatically intensifies the wheel brake.

Wheel brake pressure controlling system in which vehicle operating

The invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling the braking force applied to each wheel, in response to a condition of the vehicle in motion. A predetermined pressure increasing characteristic is provided for the hydraulic braking pressure which is supplied from a pressure control apparatus to wheel brake cylinders, on the basis of the vehicle condition, when the braking force controller initiates the control of the braking force to actuate the pressure control apparatus. And, a predetermined pressure decreasing characteristic is provided for the hydraulic braking pressure, when the braking force controller terminates the control of the braking force. The braking force controller is arranged to control the hydraulic braking pressure supplied from the pressure control apparatus to each wheel brake cylinder in accordance with the pressure increasing characteristic and the pressure decreasing characteristic to maintain the stability of the vehicle.

A brake force distribution control system comprising wheel speed sensing means S1, S3 which detect wheel speeds VWFR, VWRR of a front right wheel FR and a rear right wheel RR respectively, standard speed calculating means M1 calculating first speed value B and second speed value C from each of the wheel speeds VWFR, VWRR, and figuring out front medium value of VWFR, B and C and rear medium value of VWFR, B and C as standard wheel speeds VWSFR, VWSRR respectively, comparison means M2 calculating a difference between the standard wheel speeds VWSRR and VWSFR and driving means M3 operating a pressure control valve unit FV depending on the differences so as to modulate brake force of the rear right wheel RR relative to that of the front right wheel FR.

Distribution system for selectively controlling and supplying brake

In an electric control apparatus for a hydraulic brake control system of a vehicle, a feedback control portion is provided to produce a feedback control pulse signal indicative of a difference between a target slip ratio and an actual slip ratio. A feedforward control portion is provided to successively convert the target slip ratio in relation to a required braking force, a hydraulic braking pressure and an amount of hydraulic braking fluid, in sequence, and to convert the amount of hydraulic braking fluid into a feedforward control pulse signal. A pulse mixing circuit is connected to control portions to mix the control pulse signals for producing a mixed control pulse signal as a distinct control pulse signal. A driving circuit is connected to the pulse mixing circuit to control a hydraulic braking pressure applied to each wheel of the vehicle in accordance with the control pulse signal, regardless of the extent to which a brake pedal of the vehicle is depressed.

Growing community of inventors

Toyoake, Japan

Jun Mihara