The Design Of Electrostatic Levitation Position Control System

Non-container processing technology is able to avoid materials been affected by the wall of the container during solidification and improve the degrees of undercooling, it is an important research direction on the development of space materials science. Compared to other levitation technology, the electrostatic levitation technology does not generate additional energy input the sample, does not create additional interference factors during materials solidification process, combined with other non-contact measurement devices easily to measure the thermal properties, it is more suitable for scientific experiments of materials in space and expected to become one of the important test devices in China's space materials science in the future.Electrostatic levitation position control system is the base and core on electrostatic levitation material processing technology. There is no report that China has fully grasped the core technology. According to analysising of the theory of position control system, this dissertation designed and accomplished the electrostatic levitation position control system and achieve to control the levitation sample position steadily.The main work of this dissertation is:(1)Research of the principle of electrostatic levitation and position control of electrostatic levitation, analysis of the physical process of sample levitation and the process of position control, proposed the function of position control system, the precision of position control and the design goal of control frequency.(2) According to the design objectives and requirements, design and implement electrostatic levitation position control system of various hardware components: three-dimensional position measurement, control unit, high-voltage amplifiers, levitation structure and so on, use two parallel laser beams of different wavelength light source light the sample perpendicularly, use two vertical two-dimensional position-sensitive detectors (PSD) detect the location of the shadow of the sample, achieve to the position measurement of the levitation sample; use STC11F32XE microcomputer as the core of contil unit to achieve the three-dimensional position signal collection, position control operation and output of three-dimensional control signals; select for the high-voltage amplifiers and design the electrodes structure, format the hardware platform of electrostatic levitation position control system.(3) In terms of software, design and implement the software of electrostatic levitation position control system. Use C language programming each program running in the system, achieve the various functions of position control system. Design and implement of the main program, serial interrupt routines, control routines and digital interrupt routines and so on. In terms of algorithm, process data of position measurement according to coordinate rotation principle, proposed integration detachment PID control algorithm and parameter tuning method for electrostatic levitaion position control system.(4)In this experiment, the control system achieved to steadily control the position of levitation sample.