Research On Modeling, Control And Experiment Of A High-Response Short Stroke Linear DC Motor

The precision control system of using linear motor direct driving is a new feed transmission mode developed in recent decade. Since the precision control systems of using linear motor direct driving can eliminate the disadvantages of the conventional rotary-to-linear conversion mechanism, improve greatly the rapid response and control precision of the direct drive feed transmission system and have a wide application future in the manufacturing industry, which have received wider attention in the academic field and in the industrial field.In this thesis, the theory and method of position servo control for a new high-response short stroke PM linear DC motor are proposed. Its mathematical model, the control strategy, design and implementation of the servo control system and some related experiments are mainly studied. The technological problems appearing in the processing of researching on a linear servo drive system for the dynamic focus module of using the high-response short stroke PM linear DC motor are solved. Which are based on comprehending theoretical and practical meaning, and research status and developing trends of the linear motor and its control technology.Firstly, the configuration features and operating principle of the high-response short stroke PM linear DC motor are described. Next, the coupling relations between mechanical and electromagnetic equations are deduced by means of the energy transfer mechanism using a method of theory analysis combined with practice application. The mathematical model of the high-response short stroke PM linear DC motor is proposed, and the block diagram of the dynamic model and transform function equations are given. Finally, the dynamic performance and the parameters of affecting the dynamic performance are analysed, and the effectiveness of the mathematical model is verified by the experimental results.The model-based position feedforward tracking control algorithm and strategy are proposed to satisfy the requirement of position tracking performance based on the research on the mathematical model of the servo control system. The feedback and feedforward controllers are designed. A digital-analog mixed dual closed-loop (position loop and current loop) position servo control system is constructed. The position loop adopts the digital controller based on the Digital Signal Processor (DSP- TMS320LF2407A) to implement the position feedforward tracking control algorithm and achieve the high control accuracy, and the electric current loop and the pulse width modulation (PWM) employ the analog controller to meet the requirement of the real-time control for the current loop. In addition, the hardware of digital controller is developed using bus-isolated technology with practical application, the software of digital controller is designed, and some key techniques are also discussed in hardware and software design.The experimental research of the linear DC motor and the position servo control system are implemented by means of a DSP-based development platform for the particularity of experiment method. Utilizing the system self-contained linear optical encoder in the linear DC motor, the model parameters and performance parameters are determined. The effectiveness of the proposed control algorithm is verified through the contrastive experiment. A prototype system of the linear motor applied in the direct drive dynamic focus module is developed.Some theoretical and practical achievements are obtained through deeply researching the operating principle, mathematical model, control algorithm and strategy, design and implementation of the servo control system and related experiments of a new high-response short stroke PM linear DC motor in this thesis.