Active vibration control systems as prototyping tools for passive vibration absorbers

Vibration absorbers are a well established method to reduce structural vibrations. Designing a vibration absorber consists of selecting its mechanical properties. In the automotive industry, the final design phase usually comprises extensive tests with different absorbers in the vehicle and subjective and objective evaluation of the results. This requires hardware modifications between different tests. In this paper, an approach is suggested that can assist in the development of vibration absorbers. It is based on tuning an active vibration control system such that it reproduces the behavior of a specified vibration absorber. This behavior can then be changed electronically without modifying the hardware. Two different control approaches are compared. In the first approach, the apparent physical properties of a vibration absorber are directly modified through well-known acceleration, velocity or displacement feedback structures. In the second approach, a desired dynamic mass transfer function for the vibration absorber is prescribed and an H₂-norm optimal model matching problem is solved. Both approaches are straightforward from a theoretical point of view, however, some problems occurred during the practical implementation. Along with the results, these problems and related ad-hoc modifications are discussed