Toyota Jidosha Kabushiki Kaisha

Toyota Central Research and Development Laboratories, Inc.

Yasuji Arai

Shunichi Doi

Hiroyuki Ikemoto

Osamu Yasuike

Nobutaka Oowa

Nobutaka Owa

In this vehicle height adjustment system, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. Working fluid supply/discharge means are provided corresponding to the actuator assemblies and supply and discharge working fluid to and from their pressure chambers. Wheel loading detection means are provided for sensing parameters representative of the loadings imposed by the vehicle body on the wheels, and vehicle height detection means are provided for sensing the heights of the vehicle above the wheels. A means for computing and control controls the working fluid supply/discharge means, based on the deviations of the actual wheel heights from standard wheel heights, and carries out control adjustment of the actual wheel heights to the standard wheel heights by, at least when the vehicle speed is below a determinate value, carrying out a correction to the adjustment control of the working fluid supply/discharge means, based upon the deviations of the actual wheel loadings from standard wheel loadings, by an amount appropriate substantially to eliminate the loading deviations.

System for vehicle height adjustment with loading deviation correction

In this vehicle height adjustment system, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. Working fluid supply/discharge means are provided corresponding to the actuator assemblies and supply and discharge working fluid to and from their pressure chambers. Vehicle height detection means are provided for sensing the heights of the vehicle above the wheels. A means detects the rate of change of the steering angle of the vehicle. And a means for computing and control controls the working fluid supply/discharge means, based on the deviations of the actual wheel heights from standard wheel heights, and carries out control adjustment of the actual wheel heights to the standard wheel heights, by performing a prediction calculation of the fluctuations in wheel heights caused by vehicle rolling from the rate of change of steering angle as detected by the means for detecting the rate of change of steering angle and from the vehicle speed as detected by the vehicle speed detecting means, and by carrying out a correction to the adjustment control of the working fluid supplying and discharging means, based upon the calculation result, by an amount appropriate substantially to eliminate the wheel height fluctuations.

System for vehicle height adjustment with steering angle change rate

In this system for vehicle roll control, a plurality of duty radio controlled actuator assemblies are provided, one corresponding to each one of the vehicle wheels, and resiliently suspended from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding vehicle wheel as a result of the supplying or discharging of working fluid to or from its pressure chamber. Working fluid supplying and discharging means supply working fluid to and discharge working fluid from the pressure chambers of the actuator assemblies. The system further includes means for sensing the road speed of the vehicle, and means for sensing the steering angle of the vehicle. Vehicle height detection means are also provided for sensing the heights of the vehicle above the vehicle wheels. A means for computing and control calculates the deviations of the actual detected vehicle body heights from standard vehicle body heights; when a certain condition is satisfied, it controls the working fluid supplying and discharging means according to a first duty ratio according to the deviations of the actual vehicle body heights, so as to maintain the deviations of the actual vehicle body heights within predetermined ranges; and then it controls the working fluid supplying and discharging means in the reverse order according to a second duty ratio.

System for vehicle body roll control with overshoot prevention

In this system for vehicle roll control, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. Each of these actuator assemblies is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding vehicle wheel as results of control signals being supplied to it. A plurality of control means are provided corresponding to the actuator assemblies and serve to supply control signals to them. A vehicle speed detecting means senses the road speed of the vehicle, a steering angle detecting means senses the steering angle of the vehicle, and a lateral acceleration detecting means detects the lateral acceleration of the vehicle body. A means for computing and control predictingly computes the roll angle of the vehicle body from the vehicle speed sensed by the vehicle speed detecting means and the steering angle sensed by the steering angle detecting means, and controls the plurality of actuator assemblies, via the plurality of control means, in accordance with the computed roll angle, so as to reduce the rolling of the vehicle body to keep the vehicle body rolling within a determinate range. This computing and control means is further adapted to compare the direction of vehicle steering as detected by the steering angle detecting means with the direction of lateral acceleration of the vehicle body as detected by the lateral acceleration detecting means, and does not effect such controlling of the plurality of actuator assemblies, when the direction of vehicle steering is opposite to the direction of lateral acceleration of the vehicle body.

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Toyota, Japan

Yasuji Arai