Active control of the dynamics of lightweight mechanisms

With the intention to drive mechanisms at higher speeds, reduced weight and improved accuracy of operating conditions, the influence of dynamic effects grows in proportion. As a result, the elasticity of the mechanisms structures has an impact on path of the motions which has to be realized by the linkage system. Improvements can be achieved with the aid of active control applied to these structures. As an example a four-bar linkage system will be used to demonstrate the effectiveness of the introduced active elements. The results gained by simulation using a the hybrid multibody system model have been verified both by numerical calculations based on finite element models and by experiments. They give us the needed informations like regulating distance and frequency range to develop suitable actuators. It will be shown, that in case of a suitable choice of the actuators and its positions the deviations of the path of motion can be compensated. Several actuator concepts will be introduced and their most important features will be pointed out.