Robust control design for a thixoforming process

In this paper a robust control design based on μ-Analysis and -Synthesis for a Thixoforming Process is presented. This process is a new manufacturing technology where metals are processed in their semi-solid state. To automate the process strict performance requirements have to be taken into consideration. The process model is characterized by strong nonlinearities and uncertain model parameters, which are treated as structured uncertainties. Input signal characteristics and performance requirements are taken into account by using different weighting matrices. To meet the performance requirements two controllers of different structure have to be designed for a speed and a force control in the manufacturing process. The closed loop system containing the thixoforming process and the two switching robust controllers has been analysed and simulated.