The Study On ControllingTechnology Of Precision Positioning Platform For Micro-machining

Because of the machining dimensions, accuracy and process stability of micro machining, movement units for micro machining system are demanded to be with higher precision, resolution and real-time performance than general machining system. Macro and micro dual-drive precision positioning platform has been widely used in the microelectronic machinery,precision machining, aerospace and other fields, which is one of the most promising precision positioning mechanisms currently. Therefore, macro and micro dual-drive precision positioning platform control technology and its realization are studied, and works completed are presented as follows:1. Analyze the hysteresis of piezoelectric actuators, design experiments to achieve the Preisach model of hysteresis; proposed the polynomial fitting modeling method and constructs the polynomial fitting model. At the same time, according to the step response curve, established the dynamic model and the simulation model of the output displacement of piezoelectric actuator.2. Application the characteristics model to the precise positioning system, the composite closed-loop control system of feed-forward+feed-back was designed and optimized.3. According to the simulation result, proposed the macro and micro two level of precision positioning control system of general PC AC servo motion control system+embedded system. The macro motion is controlled by PC;The Micro displacement is the embedded processor and special logic control chip.4. Based on the hardware platform and control method, programming PC softwa re and the embeddedprocessor, and carry out a precision motion control experiment.Matlab simulation of the relevant and Location test results showed that,compared with the traditional Preisach model, proposed polynomial fitting model, with high accuracy; proposed composite control system of feed-forward+feed-back, with high control speed and keep the control precision of the original. The control structure of ARM processor+FPGA was designed, achieved precision positioning control with high speed and accurate. Real time and reliability of the system is improved.