Semiactive Control of Multiple Degree of Freedom Systems
Abstract Semiactive control of systems with multiple degrees of freedom is addressed. Two systems representing a pitch-plane model of a vehicle and a single suspension are used to illustrate the results. The dynamic simulations show the well-known compromise between resonance control and isolation, due to passive dampers. It is shown that semiactive dampers also compromise between controlling different bodies. For skyhook and groundhook control policies, the control of one body is achieved at the cost of less control on the other bodies. For instance, in a single suspension model, skyhook semiactive dampers better control the body resonance, but significantly increase the axle resonance (wheelhop). The groundhook dampers provide a better control of wheelhop at the expense of increasing body resonance. A hybrid control policy that combines the effect of skyhook and groundhook policies is introduced. This policy can be used to provide the proper control on all bodies, while using the hardware common to existing semiactive dampers.