Motion Control Of Air Bearing Positioning Stagebased On Relay Feedback Technology

This dissertation focuses on the relay feedback method and its application on motion control of air bearing positioning stage, which is driven by linear motors and developed for IC packaging application.Firstly, we introduce the working principle and the applications of the relay feedback method. Then we analyze and investige the characteristics of two kinds of relay modules. By aiming at the PID parameters tuning on speed control of servo control system, we carefully study the parameters of the saturation relay module, and propose the relay parameters setting rules. Experimental results validate the proposed rules and show that the tuning of PID controller parameters is quick and effective.Secondly, we design a disturbance observer based on relay feedback for position control, since the external disturbances are the key source that affecting the platform's performance. With the simple thrust model structure of linear motor, we employ the relay feedback to identify the model's parameters and establish the control model of platform. Moreover the disturbance observer is used to resist external disturbance and eliminate factors of model errors.For realization and experimental research of the control algorithm, a control system is set up which uses the dSPACE DS1103 controller. The control system includes two parts. One is the interface programmed by Control desk, by which the users can record the real time data, manage the hardware, set parameters and capture the states and results of experiments. The other is the real time operating program based on Matlab\Simulink, which is in charge of the tasks such as sampling, controlling, code generating and so on. Experimental results show that the proposed algorithm can resist external disturbance and achieve high positioning accuracy.