High Precision Position Control based on Active Disturbance Rejection Control for Galvanometer Scanner System

To satisfy the high precision and high dynamic requirement, the high precision position control based on the active disturbance rejection control (ADRC) is proposed for the galvanometer scanner system, whose control scheme consists of four parts: two tracking differentiator (TD), the extended state observer (ESO) and the nonlinear proportion-integration-differentiation (NPID) controller. One TD is used to arrange the transition process of the position command to solve for the contradiction of the high dynamic performance and the high precision for the system. The other TD is proposed to calculate the rotor speed from the rotor position signal, which can solve the high frequency noise issue of the traditional differentiator based rotor speed calculation approach. The ESO is proposed to estimate the parameter variation and the load disturbance of the galvanometer scanner drive system, while the nonlinear PID controller is used to achieve the high precision position control by compensating the various uncertainties. The resulting control has the simple structure and low computation burden, which can guarantee both the high dynamic performance and high precision for the system position control. The simulation and experimental results verify the effectiveness of the proposed position control of the galvanometer scanner system.