13 Semi-Active Suspension Systems II Concepts of Semi-Active Suspension Systems Karnopp’s Original Concept • Sky-Hook for Comfort • Extended Ground-Hook for Road-Tire Forces • Semi-Active Actuators and Their Models Control Design Methodology General Design Methodology • Clipped Active Control • MOPO Approach • NQR Approach • Preview Control Michael Valásek ˇ Czech Technical University, Prague Properties of Semi-Active Suspensions: Performance Indexes Influence on Comfort • Influence on Road Friendliness Willi Kortüm German Aerospace Research Establishment Examples of Practical Applications Passenger Cars • Road-Friendly Trucks • Trains • Airplanes The concept of suspension systems is treated for a broad array of vehicles including trains, airplanes (during ground motion), and off-road vehicles. The vehicle. | 13 Semi-Active Suspension Systems II Michael Valâsek Czech Technical University Prague Willi Kortüm German Aerospace Research Establishment Concepts of Semi-Active Suspension Systems Karnopp s Original Concept Sky-Hook for Comfort Extended Ground-Hook for Road-Tire Forces Semi-Active Actuators and Their Models Control Design Methodology General Design Methodology Clipped Active Control MOPO Approach NqR Approach Preview Control Properties of Semi-Active Suspensions Performance Indexes Influence on Comfort Influence on Road Friendliness Examples of Practical Applications Passenger Cars Road-Friendly Trucks Trains Airplanes The concept of suspension systems is treated for a broad array of vehicles including trains airplanes during ground motion and off-road vehicles. The vehicle suspension has many important functions Control of the attitude of the vehicle body with respect to the road surface Control of the attitude of the wheels with respect to both the road surface and the vehicle body Isolation of the vehicle body from forces generated by the roadway unevenness Control of the contact forces between wheels and the road surface Control of lateral and longitudinal motions All these functions can be significantly improved via electronic control added into the system. This makes the suspension active. In this section the treatment of suspension is limited just to the vibration control. We primarily focus on the isolation function and the contact force variation control in particular the normal component of it . The lexicon commonly used in vehicle dynamics semi-active control implies that the control actuator requires very little power. Such control is where the actuator possesses many attributes of conventional active control but which requires very little control power. A semi-active actuator typically dissipates energy thus it does not raise stability concerns. Concepts of Semi-Active Suspension Systems Karnopp s Original Concept The
