ACTIVE SUSPENSION SYSTEM FOR A MOTOR CAR
A vehicle exists to carry someone or something from one place to another. In doing that there should be as little disturbance as possible of what is being carried. If the load is inanimate, the less the disturbance the less in the way of special packing will be necessary. If animate, then the better the condition after the journey, the longer the journey can be without fatigue. When the driver has less fatigue then he can maintain a better concentration on driving the vehicle.
The basic need for a suspension system in a vehicle is not entirely caused by human susceptibility to the discomforts of vibration, although isolation from the road-induced disturbances is a highly desirable design aim. Maintaining contact between the wheels and the road surface is far more fundamental, as the control and stability of the vehicle relies upon it totally.
It is essential for a car suspension system to fulfill some basic requirements. The most important of them are listed below.
The ride comfort is determined by the acceleration of the body. The acceleration forces are experienced by the passengers as a disturbance, and set demands on the load and the vehicle. The suspension system has the task to isolate these disturbances, resulting from the uneven road conditions, from the body. The lower the acceleration, the better the ride comfort.
Safety is dependent on the ability of the wheels to transfer the longitudinal and lateral forces onto the road. The vehicle suspension has the task of keeping the wheels as close to the road surface as possible. Wheel vibrations must be dampened and the dangerous lifting of the wheels must be avoided. For complex active suspension systems, additional emphasis should be given on the Failure Mode...