Research on NonLinear Active Disturbance Rejection Controller for Permanent Magnet Synchronous Linear Motor

Permanent magnet synchronous linear motor (PMSLM) has the characteristics of high reliability and high efficiency. Aiming at the problem that PMSLM is used in various high-precision semiconductor packaging equipment, the application environment is complex and changeable, and various disturbances directly affect its motion performance, a nonlinear active disturbance rejection control method emerged. Due to the use of extended state observer (ESO) in active disturbance rejection control (ADRC), the total disturbance can be estimated in real-time, and precise mathematical models are not strictly required in ADRC, thus the ADRC has a good load disturbance rejection performance, fast set-point tracking performance, and strong robustness. The linear active disturbance rejection control (LADRC) has a relatively simple structure and its parameters can be tuned with the bandwidths of observer and controller. The nonlinear active disturbance rejection control (NLADRC) has more freedom and possibility than LADRC, so it must also have better adaptability. In this paper, the PMSLM of wire bonding machine is taken as the research object. Firstly, the open loop transfer function of the system is obtained through step response experiments. Then, in order to solve the problem that using conventional observers is easy to cause the phase lag of the system, a NLADRC based on a nonlinear extended state observer(NLESO) is designed to improve the system observation accuracy for disturbances. The total disturbance inside and outside the system can be traced from ESO, and then the controller can compensate in the nonlinear state error feedback (NLSEF) section, which has a significant effect on the control effect. Finally, the results show that compared with the PID and LADRC, NLADRC has better motion control effect, which makes the system settling time shorter, the overshoot is smaller, and the anti-interference ability is stronger,which meets the needs of engineering applications.