Performance Limitations for Active and Passive Suspensions
Keywords. Automotive, suspension, systems theory.
This paper investigates a systems approach to suspension design for
passive and active suspensions. We seek to understand the set of
dynamic responses which are achievable for both passive and active
systems. To this end, we view a suspension system as a mechanical
multi-port network and draw on concepts from electrical circuits
such as passivity and reciprocity. We give an example of a
suspension which is stiff to loads on the sprung mass, is soft
to road disturbances, which can be realised actively but not passively.
Degrees of freedom and constraints on various transfer functions are
examined for quarter- and half-car models.