Research On The Control System Of Precision Stage Based On Material Selection

With the development of science and mechanical manufacturing technology, precision machining stage system with high precision and high resolution plays an important role in modern industry and scientific research field. The whole performance has defect and the demand of environment is strict in the developed precision and ultra-precision stage. By comparing the ultra-precision stage developed at home and abroad, the conclusion can be drawn as follows: ceramic material, aerostatic guideway and direct drive technology are the key technology of ultra-precision stage. The open numerical control system is chosen certainly.Through researching on key technology of precision stage, the linear motor, close type aerostatic guildway, exposed linear encoder and high performance motion controller are chosen to establish the whole motion system. The models of the parts are determined by calculating and analysis to meet the challenge of precision and speed for the system.The general used method in control engineering field is the classical PID control and its improved methods. Considering the stage character, load variation, disturbance and economic factors, the classical PID controller is used and unit-feedback PID control, PID with acceleration feedforward control, position and velocity dual loop feedback control, Smith prediction control system were analyzed separately through computer simulation and control results of slider made of different materials were compared. To solve the problem of control system selection, a synthesis evaluation index was built using analytical hierarchy process to seek an optimum control method.At last, the I/O interface and the connection to external device of the motion system were discussed and the pin definitions were designed for subsequent works.