Robust Control of High Speed High Precision Linear Motion System

This paper presents an improved robust control of a high speed high precision XY-table linear motion system used in semiconductor wire bonding machine. H-infinity robust control is implemented in both inner velocity loop and outer position loop to achieve high and consistent control performance even in the presence of considerable resonance uncertainties and external disturbances. Auto-tuned feed-forward compensation based on fuzzy logic method is employed to obtain satisfactory dynamic and settling performance. High close loop bandwidth has been yielded, and high acceleration of 20g (1g = 9.81m/s(2)), high speed of 0.9m/s can be achieved with the dynamic error of 2 mu m, settling error of 1.2 mu m and static error of 0.2 mu m.