Design Of High Precision Force Actuator Control System

Telescope is an important tool for astronomical observations,the greater its caliber,the stronger its collection of light capacity,the higher its the resolution.With the increase of diameter,the primary mirror will be affected by wind,temperature and gravity,Which will change the shape of the telescope and affect the imaging quality of the telescope.Therefore,it is necessary to control the main mirror shape in real-time by correcting the wind,temperature and gravity on the impact of the mirror to improve the image quality.In a large ground-based telescope,the control of the primary mirror shape in real-time can be achieved by controlling the force actuator in the active optical system.In recent years,active optical technology has become one of the important technologies in large-scale ground-based telescope system.It belongs to the intersection of automatic control,precision machinery,computer,optics and automatic control.Its principle is to detect the distortion of the mirror surface by the wavefront sensor and calculate the correction force and its coordinate,and then transfer the required correction force value to the corresponding force actuator via the bus.The control force actuator to expert pressure or tension,to achieve active adjustment support force,to control the shape of the purpose.The paper is divided into four parts:In the first part,the working principle and mechanical structure of the force actuator are introduced.On the basis of this,the overall scheme of the force actuator control system is designed.The second part of the control system needs to design some of hardware circuit,including the system power circuit,force signal acquisition circuit,motor drive citcuit and force actuator control circuit,and to set up the system experimental platform.In the third part,the advantages and disadvantages of the closed-loop control strategy in the force actuator control system are analyzed,and design of the variable-speed integral PID controller with dead zone is completed,Then,the software design method of the force actuator control system is introduced.The detailed program flow chart is designed.The fourth part of the force actuator control system to complete the performance test,and experimental results analysis,including force actuator control experiments,force acquisition single conversion accuracy test and calibration,force actuator performance testing.From the experimental results,it can be seen that the system can work in the expected way,can achieve the precision of the primary mirror shape correction force,and have a good response performance,with a certain degree of engineering practical value.