The Control System Research Of Precision Micro Actuator Based On FPGA

Compared with piezoelectric, electrostatic and thermal driven methods, maglev planar motor micro actuator methods have advantages, such as the low driving voltage, small resistance movement, high freedom, good reliability, etc.. With the development of processing industry,maglev planar motor has become to be the focus of domestic and international research.Sampling rate of control system has a direct impact on the control precision of maglev planar motor micro actuator. So selecting a high clock frequency FPGA to be the main chip can not only improve the efficiency of the program, but also have great application space in large amounts of data computing and peripheral circuits’ extensions.The main contents are as followings:1. The structure and the principle of the novel magnetic levitation micro actuator with moving-windings were introduced. Based on the analytical model magnetic field distribution derived by using the equivalent surface current method, the dynamic model of the magnetic levitation system was built. Then, a control system using PID control strategy was constructed,and the dynamic and stability performances were verified by simulation experiments.2. In order to increase the respond speed and stability of the control system, a control system of the magnetic levitation micro actuator based on high-speed EP2C5 FPGA was built. In the system, several corresponding circuits, such as sampling circuit, communication circuit were designed. A data sampling circuit was designed by using the chips of AD7671 and AD5545 to manipulate and output circuit, which achieves the micro actuator’s functions of data acquisition and data output. A communication circuit is designed to realize hardware connections between control circuit and upper computer via RS232.3. The software for FPGA-based magnetic levitation micro actuator system software werealso programmed according to Software Quartus II to achieve ADC sampling, FIFO caching,data filtering, algorithm controlling, DA controlling and communicating with upper computer;Functions and implementation methods of algorithm were described to finish program writing and to realize functions of the modules as well.4. The FPGA-based experimental system of the magnetic levitation micro actuator was constructed finally. The levitation status of the mover can be tested by the odd current sensors,and the information can be collected and illustrated by the PC via Delphi interface. The experiment results show that the control system can realize high-precision position with high respond speed and good tracking performance. The system is able to achieve a precision control of 1μm in the range of 2mm.