Fractional Order Modeling And Control For Galvanometer Scanner System

The galvanometer scanner systems play an important role in the ultra-precision laser system,due to its fast response,high bandwidth and large scanning range.It is widely used in laser processing and laser scanning fields,such as stereo lithography apparatus,selective laser sintering and confocal microscopy.Nevertheless,the plant uncertainties,hysteresis and time delay reduce the control performance of the system,which seriously affect the accuracy of the ultra-precision laser system.In order to overcome the above difficulties,the galvanometer scanner systems are studied.We establish the system's fractional order mathematical model and study the application of related fractional order control algorithm in the galvanometer scanner systems.The main work of this paper includes the following content:(1)The working principle and structure of galvanometer scanner systems are studied.Meanwhile,we establish the fractional order model to describe the rate-dependent hysteresis of galvanometer scanner system.Finally,the PSO algorithm is implemented to identify the parameters of the fractional order model.(2)The stability conditions of fractional order uncertain systems are analyzed.In order to guarantee the frequency-domain robust performance and time-domain response of fractional-order uncertain systems,and a new design method of fractional-order robust controllers is proposed,where the parameters of fractional order controller can be solved by the particle swarm optimization algorithm.(3)In order to reduce the dependence on the system model in the solution of the fractional PID controller,the application of data-driven theory in the fractional order system is studied,where iterative feedback tuning theory is combined with the fractional PID control algorithm.