Robust performance control of electrohydraulic actuators for camshaft machining

Summary form only given. Nonlinear dynamics of the electrohydraulic servoactuator are represented by linear models corresponding to different ranges of motion. Model uncertainty bounds are determined for each amplitude range and the corresponding robust performance controllers are designed. The controllers designed from the larger amplitude models provide robust performance for a wider range of reference signals, as demonstrated by the experimental sensitivity functions. The robust performance controllers are implemented with the corresponding repetitive controllers and feedforward controllers for the manufacturing application of non-circular turning for camshaft machining. The tracking performance results are obtained for reference cam profiles of five different scalings. For the larger reference cam trajectories, the best performance is obtained using the controllers designed from the larger model amplitude ranges. These observations validate the modeling of the electrohydraulic system using linear models for different input amplitude ranges.