Synthesis Methods For High-speed High-precision Servo Controllers Based On Two-degree-of-freedom Theory And Internal Model Principle

High-speed high-precision motion control technology is the core of the equipment manufacturing industry. As the products of the equipment manufacturing industry become smaller and more integrated, the concept of sustainable development and energy saving becomes much more popular, the demands on the performance and efficiency of the manufacturing equipments are shooting up day by day. Therefore, the advanced servo control systems are facing great challenges.There are two key aspects in the design method of the high-speed high-precision motion controllers:first, the bandwidth of the system should be as high as possible, so the response to the reference signal can be faster. Second, modeling the system accurately and compensate the nonlinear components to make the system operate in the whole frequency domain stably. This dissertation has analyzed the model characteristics of the servo control systems in equipment manufacturing industry, and proposed the design methods of the controllers for the different operating modes and object models. The design methods have been verified in the wire bonder X-Y platform and permanent magnet synchronous motor test platform, the positioning precision and response speed are increased. The main contents of this dissertation are as follows:(1) Mathematical modeling the permanent magnet synchronous motor and voice coil motor. The kinetic model of the servo systems are described using the differential equations, transfer functions and state space equations.(2) The synthesis method for high-precision fast-response current controller has been described. Design methods of two kinds of current PI controllers and decoupling compensate algorithm are proposed. Simple but efficient dead-time compensate algorithm and over-modulate voltage compensate algorithm are introduced. Meanwhile, the design methods of discrete-time low-pass filter and notch filter are demonstrated.(3) The synthesis method for the high-speed high-precision velocity controller has been described. A novel IP velocity controller based on two-loop two-degree-of-freedom (2-DOF) controller is presented. It can modify the closed loop zero of the system using the feedforwd parameter, so the response speed is higher than it of the conventional controller; the design methods of the velocity controller based on feedforwd plus feedback controller are modified. On the other hand, in order to eliminate the phase lag and sampling noise of the feedback signal in the servo systems, a simple structure of the predictive observer is introduced. It can be implemented in the servo system with2-DOF controller. The control accuracy is2mm/s when the velocity is350mm/s.(4) The synthesis method for high-precision high-acceleration position controller has been described. In order to compensate the disturbance and the model uncertainties in the servo system, the design method of disturbance observer is proposed, a novel2-DOF control algorithm based on the disturbance observer and phase lag compensation is proposed, the position control accuracy could be under5um when the acceleration is6.5g. The general structure of the discrete-time plug-in repetitive controller is given, and a practical robust criterion of the repetitive control system is derived. The design method of the stabilizing compensator in the plug-in repetitive controller is improved, which could increase the robustness of the system. Simulation and experiment results show that the position error of repetitive reference signal is only1nm.This dissertation is focused on the control theory of the high-speed high-precision servo control system. Based on the2-DOF control theory and internal model principle, the design method, stability criterion and general structure of the controllers in servo control system are proposed. Some good results have been achieved in simulation and experiment.