Fuzzy PID control for AC servo system based on Stribeck friction model

Friction is the key factor influencing high precision and super low-speed running performance of AC servo system. In order to factually simulate the influence of friction on AC servo system, three-loop nonlinear model of industry AC servo motor including measured Stribeck friction disturbance factors is established. The control performance of position loop is simulated and studied by adopting traditional PID and fuzzy PID. The results show that Stribeck friction can lead to “flat top” of position tracking and “dead zone” of speed tracking adopting traditional PID, while fuzzy PID decreases the influence of friction on servo system performance and improves tracking precision and robust performance of the system.