Design Principles for Vibration Control Systems Using Semi-Active Dampers

Electronically controlled vibration isolation and control systems have recently reached at least the prototype phase in a number of fields of application. Of particular practical interest are semi-active systems which require very little actuator power. Semi-active dampers in the form of rapidly modulated hydraulic shock absorbers have been used for example in automobile suspensions to achieve some of the benefits of fully active servo-mechanism systems but with much reduced cost and complexity. Various damper configurations and feedback control schemes are discussed. The design choices to be made can often result in similar system performance and yet can lead to dramatic differences in the frequency response requirements for the actuators used in the semi-active dampers.