Research Of The Vacuum Manipulator Control Methods Based Dynamics Model

In the semiconductor industry, a cluster tools is several different but related process modules integrated into one set of producing equipment, to meet the requirements of reducing human operation to improve the clean level, shortening the manufacturing time, increasing the throughput, and decreasing the cost. Within this mainstay manufacture equipment, a vacuum manipulator is indispensable in that it transfers wafer between neighboring chambers. Currently the vacuum manipulators have been developed to transfer wafers ranged from 200mm to 300mm. Due to their sensitive nature and high commercial value, relevant techniques are being blocked by western countries. Counterpart researches are hugely required. This thesis has carried out research on the control method of vacuum manipulator, supported by Ministry of Science and Technology's key funding on super large-scale integrated circuit manufacturing equipments and based on the vacuum manipulator manufactured by ShenYang XiaSun Robot Automation Corporation .The thesis analyzes the key issues need to solve about the vacuum manipulator. Based on studies on kinds of advance control approaches, a systematic research has been done toward the model making, controller structure, path planning ,and dynamics control, with contributions as follows.(1) Both the kinetics model and the inverse kinetics model have been solved for the real-time control of the vacuum manipulator. Dynamics equations have been given for the serial chain of the parallel arms of the vacuum manipulator through the Lagrange-method.Dynamics model making was set up through the Lagrangc D-Alembert method, in accordance to the mixture of drive and non-drive joins in the parallel arms, which makes way for the realization of fast-speed precious control of the vacuum manipulator.(2) Structural design of an open robot controller tackling the specific characteristics of the vacuum manipulator controller. Formulation of the vacuum manipulator controller based on PMAC motion control board, rendering a solid basis for realization of an open, modular controller.(3) Based on the analysis of various path planning techniques, a modified path planning method is adopted, for the manipulator end effecter running at an allowable maximum acceleration with motion stability justified considering the dynamics equations and figure trait. Simulation results for the proposed planning are given and proved that the proposed method can meet the double requirements on efficiency and stability during the whole operation of the vacuum manipulator.(4) In the traditional motor servo control system, the mechanical coupled coriolis and centrifugal forces on the arms have been hitherto taken as disturbance on the motor shaft. In order to further improve the control precise and stability, manipulator dynamics model-oriented control is presented. First, PD computed torque control is used, with compensation given through robust control to eliminate the static error under the computed torque control under disturbance and model incorrectness. However, this proposal needs the accurate model incorrectness and the arithmetic is involuted. So putting forward a simple self-adaptive control robust arithmetic. Simulation experiments demonstrates the effectiveness of the proposed method.