Design Of Control System For Active Optics Force Actuator

With the increase in the aperture of optical remote sensors,it is an important goal of the development of optical remote sensors to maximize the accuracy of the main mirror surface shape while continuously improving the light collection capability and resolution.For large-aperture telescopes,the traditional support method is not only costly and technically difficult,but also difficult to meet the requirements of surface shape.Active optical technology can adjust the deformation of optical components in real time,ensure good shape accuracy,greatly reduce the manufacturing cost of large-aperture telescopes,improve imaging quality,and have developed into one of the most important technologies in large ground telescopes.In large-scale ground telescopes,a force actuator is used to complete the surface shape control of the main mirror,the deformation of the mirror surface is detected by a sensor,the host computer calculates the corresponding coordinates and suitable force,and then sends it to each force actuator through a corresponding bus According to the data sent by the host computer,the pressure or tension is executed to achieve high-precision control of the telescope surface shape.This thesis designs a DSP-based active optical force actuator control system,completed the following.Based on the analysis of the mechanical structure and working principle of the force actuator,the overall design of the force actuator control system is completed.The overall scheme of the control system based on the combination of DSP and CAN bus is proposed.The system design of the distributed control network using CAN bus is established,and the software and hardware requirements of the system are analyzed,and the expected performance indicators are given.The hardware circuit of the whole system is designed,including force actuator control circuit,stepper motor drive circuit,force signal acquisition circuit,power supply circuit,etc.,and a system experiment platform is built.The control method of the force actuator is designed.The variable structure parameter self-tuning fuzzy PID controller is used to correct the output of the force actuator.The S curve is used as the acceleration and deceleration control method of the stepper motor,which overcomes the load torque and the system torque caused by the speed change.Complete the software design of the force actuator system,complete thesystem initialization subroutine,sensor acquisition subroutine,communication subroutine(serial port and CAN bus),etc.,and draw a detailed program flow chart.Complete system performance testing,including force actuator control method testing,stepper motor acceleration and deceleration control method testing,system performance testing,sensor testing,etc.The control method of the force actuator was tested,and the performance and effectiveness of the control algorithm were verified.The experimental results show that the system can meet the accuracy requirements of active optical profile correction,meet the expected requirements,and respond quickly,which has certain application value in engineering.