Dynamic characteristics of mechanical system in linear motor feed system

To obtain the desired dynamic precision, aiming at the dynamic characteristics of the mechanical system neglected in previous researches, the dynamic model of mechanical parts in linear motor feed system is established with d'Alembert principle to analyze the dynamic characteristics and influence on motion characteristics of feed system. The theoretical and experimental investigations are implemented in the mechanical system of linear motor feed test-bed. Meanwhile the influence of mechanical frequency characteristics on the dynamic precision of feed system is analyzed and discussed. The results show that the mechanical system is endowed with complex dynamic characteristics although all intermediate transmission mechanisms are canceled, which affect the dynamic precision. The higher gain in speed control loop, the higher natural frequency of mechanical system in feed direction. With the increasing feed speed, the frequency and amplitude of each vibration mode of the table increase, and for the double velocity, the displacement fluctuations of table caused by the pitch vibration and yaw vibration are increased by two times.