Parameter space approach based robust MIMO controller tuning for a vacuum thermal evaporation process

The parameter space approach method for stability chart calculation is a well-known method. There are various analysis and fine-tuning tools available for controller design which are based on the determined stabilizing controller parameter space. Unfortunately the parameter space approach is currently only systematically developed and implemented for single loop PID controller tuning. This work presents an easy way (based on decoupling techniques) to expand the synthesis step of the classical parameter space approach to MIMO systems (with multiple time delay). The developed method is illustrated on the application example of a vacuum thermal evaporation process (VTA). Regarding this example, the presented approach is used to tune the parameters of the internal PID heat controllers. The VTA-process is characterized in detail before the controller design starts. Furthermore a physical model which describes the heat transfer in the process is obtained.