Design of microprocessor-controlled suspensions

Because of the energy crisis, people like to drive small cars. However, vehicles with less weight tend to exhibit higher frequency ride vibrations while being driven on the freeway. These high frequency ride vibrations are detrimental to passenger comfort. Therefore, it is necessary to design suspensions for small light vehicles which reduce the amount of high frequency ride vibrations felt by the passenger in these vehicles. In this paper the microprocessor-based control is introduced to the design of an adaptive suspension for a motor vehicle. The design is suited for two different cases. In the case of the car moving on the freeway, the feedback loop adjusts the suspension so that the apparent weight of the car is increased, thereby causing it to respond with lower frequency ride vibrations. In the case of changing lanes and making turns, the feedback loop adjusts the suspension so that the apparent weight of the car and the damping ratio are modified with effective road-holding.