Method and system for controlling active suspensions of a vehicle during acceleration and deceleration

A system for controlling a plurality of active suspensions in a vehicle which is provided corresponding to each wheel of a vehicle, by charging and discharging a fluid to independently control height of said active suspensions to attain a reference vehicle height, the system comprising:

• a longitudinal G-sensor mounted on said vehicle for detecting a longitudinal acceleration of said vehicle and for producing a longitudinal acceleration signal;
• longitudinal hysteresis control means responsive to said longitudinal acceleration signal for attaining longitudinal control without fluctuation and for generating a longitudinal control signal;
• a vertical height adjusting switch mounted on said vehicle for simultaneously changing a stroke by a same amount for each active suspension and for generating a signal of reference vehicle height for said each active suspension;
• longitudinal variation calculating means responsive to said longitudinal control signal and said reference vehicle height signal for computing a quantity of said fluid in accordance with said longitudinal acceleration and for producing a first quantity signal;
• a lateral G-sensor mounted on said vehicle for sensing a lateral acceleration of said vehicle and for generating a lateral acceleration signal;
• lateral hysteresis control means responsive to said lateral acceleration signal for attaining lateral control without fluctuation and for generating a lateral control signal;
• lateral variation calculating means responsive to said lateral control signal and said reference vehicle height signal for computing a quantity of said fluid in accordance with said lateral acceleration and for producing a second quantity signal;
• control quantity calculating means responsive to said first and second quantity signals for calculating a control quantity and for generating a control quantity signal;
• a vertical G-sensor provided for each active suspension to detect an acceleration in a vertical direction of said active suspension and to produce a vertical acceleration signal;
• vertical acceleration control means responsive to said vertical acceleration signal for attaining vertical control without fluctuation and for generating a vertical control signal;
• a suspension stroke sensor provided for each active suspension to detect a stroke of said active suspension and to generate a stroke signal, and stroke control means responsive to said stroke signal for generating a stroke control signal;
• control means responsive to said vertical control signal and said stroke control signal to control said active suspension system;
• means for supplying said control quantity signal to said active suspension system to reduce delay in vehicle attitude control by said active suspension system;
• calculating means responsive to said longitudinal acceleration signal for computing a changing amount of vehicle height dependent on an actual amount of said longitudinal acceleration;
• and
• correcting means responsive to said calculating means for simultaneously lowering said reference vehicle height in a linearly proportional function of said actual amount so as to lower said reference vehicle height by a same displacement amount for said each active suspension, wherein said control means controls said active suspension system based on said lowered reference vehicle height.