The Study of Self-tuning Robust Control in Dual Linear Motors Synchronous Servo System

The gantry-moving boring-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 variation, unmodelled dynamic and the nonlinear uncertainty. These factors will make the performance of the servo system worse, so they must be considered in servo drive system of high precision, tiny-feed numerical control machine. A new self-tuning regulator control method is presented for the dual linear motors synchronous servo system in the paper. Recursive least squares identification algorithm with insensitive region and projection tuning is applied for parameters real-time identification of the controlled plant, and H_infin robust control algorithm is used for parameters real-time calculation of the regulator. H_infin robust self-tuning controller is applied for the unknown and bounded disturbance, parameter uncertainties and unmodelled dynamics. The system will automatically tune the parameters of the robust controller so that the influences can be suppressed effectively. The simulation results indicate that the proposed scheme is effective and has a stronger robustness, and meets demand of speed synchronized control as well as position synchronized control for the dual linear motors synchronous servo system