Coordinating Control Research Of A Dual-Stage Actuator System

With the progress of the times,multi-stage actuators with long travel,high positioning accuracy,strong robustness,and fast response speed have become urgent needs in the field of precision engineering today.The dual-stage actuator is a new high-precision positioning device that combines the traditional large-stroke actuator and the smart material-based actuator and is widely used in mechanical hard disk drive,micro-robots and other fields.In the 21 st century when the nanotechnology has become so popular around the world,how to improve the accuracy in fast and large strokes is an urgent problem to be solved.,it is necessary to design a reasonable control scheme of macro actuator and micro actuator to give full play to their respective advantages,and finally achieve the long travel,high-speed and high-precision positioning of the dual-stage actuator.This article is supported by the National Natural Science Foundation of China and the Natural Science Foundation of Zhejiang Province.Through the research on modeling and control methods of dual-stage actuator,to achieve the requirements of coordinated control,the main works is as follows:(1)The mathematical model is established for the dual-stage actuator.Considering the structural characteristics of the dual-stage actuator,a mathematical model is obtained by the Newton-Euler method,and the influence of the error in the macro platform is eliminated by using the friction compensator.The characteristics are obtained by analysis of the macro platform and micro platform to determine the type of the drive used,respectively.The macro platform uses a linear motor as driver,so it can meet the requirements of the long travel.Micro-platform uses a piezoelectric ceramics as the drive,so it has the characteristics of high speed,high precision and strong robustness.(2)Coordinating control of dual-stage actuator structure with the spatial filter.Considering that the spatial filter structure can split the target value and can coordinate the control displacement between the macro actuator and microactuator,a dual-stage actuator coordinated control structure based on the spatial filter is proposed.The structure split the initial desired target value into two kinds of signals: long distance and short distance,which are used as the target value of the macro-actuator and the microactuator respectively.Through the designed combined with the error transformation of the backstepping nonsingular terminal sliding mode control scheme,ultimately achieve the fast response speed,high precision and large trip tracking target of the dual-stage actuator.(3)Coordinating control of dual-stage actuator structure with the decoupled.For the coupling characteristics of dual-stage actuator structure with the spatial filter,the dual-stage actuator control scheme based on decoupling control is proposed.In this structure,an adaptive discrete sliding mode control algorithm is designed for the macro platform to achieve a fast positioning of large strokes.The microactuator adopts the predictive discrete sliding mode control with optimal control function and to compensate the tracking errors of the macro actuator.Through precise control of the microactuator improve the tracking precision of the dual-stage actuators and to meet the large-stroke,high-speed and high-precision positioning target.The simulation and experimental results in this paper show that the control structure and algorithm proposed in this paper are feasible and effective.