H∞ Robust Control for Dual Linear Motors Servo System

The gantry-moving milling machining tools that adapts dual linear motors drive is a high precision and fast motion system, the factors that influence the synchronous performances of the system are not only unknown bounded disturbances but also have parameters variety, unmodelled dynamic and the nonlinear uncertainty. These factors will make the performance of the servo system worse, so they must be considered in the servo drive system of high precision and tiny-feed numerical control machine, thus the satisfying control effect can be achieved. It is difficult to meet the requirement of the synchronous performance only by the position loop; the dynamic synchronous control in the velocity inner loop should be implemented. The problem of H_infin control for synchronous drive of dual linear servo motors used in gantry-moving milling machining center is researched in this paper. A synchronous drive controller is designed based on H_infin control theory. When loads or disturbances are changed suddenly, the H_infin synchronous controller can regulate rapidly so as to ensure the synchronous precision of the dual linear motors servo system. The H_infin feedback controller guarantees synchronous precision of the synchronous linear servo system and eliminate the inferences that are the unknown and bounded disturbance, parameter uncertainties and unmodelled dynamics. The system will automatically tune the parameters of the controller so that the influences can be suppressed effectively. The simulation results show that the proposed scheme is reasonable and effective