Design of feedforward controllers for servo systems in manufacturing applications

Presents a new approach for the design of tracking controllers using knowledge about the form of the trajectory. If there is a smooth command-path, the tracking-error can be minimized with deadbeat design. The generalised predictive control (GPC) strategy leads to good results, if an optimal control-horizon is chosen. It is pointed out that the GPC strategy uses a position-controller with a regulating function not designed for eliminating disturbances. Experiments showed that model mismatch, limited actuator power and nonlinearities reduce the tracking performance. The closed loop tracking error can be reduced down to 1% of the nominal value without feedforward controller