Research Of Particle Swarm Fuzzy PID In Astronomical Telescope Mount

Large optical astronomy telescope is an important instrument in astronomy research. Generally, it runs at very low speed, in order to track and point the target celestial bodies with high-precision. With the continued progress of astronomical observation research, it needs to obtain more sophisticated astronomical information. And that forces the telescope’s aperture increasing, leading to more nonlinear interference in telescope mount drive system. It is a great challenge for mount precision driving. Accordingly, we propose fuzzy-PID algorithm based on particle swarm optimization. With using this algorithm to control the telescope mount drive system, the precision drive of mount with mature complicated nonlinear interference is trying to achieve.Firstly, based on the introduction of current domestic and foreign ground-based astronomical optical telescope mount drive research, it analyzes the key technologies involved in mount drive system。Around the needs of key technology, the large telescopes mount drive system and its major disturbance is analyzed and modeled, and further the mathematical model of mount drive system is derived.Secondly, in view of that the conventional PID algorithm can’t deal with the telescope mount drive controlling, a particle swarm fuzzy-PID controller with good stability and robustness is used to control the mount drive system.1) A fuzzy-PID controller is designed;2) Considering that the fuzzy PID controller is difficult to achieve optimal because of expert experience, it weights the input and output of the fuzzy-PID controller. The fuzzy membership functions are optimized by particle swarm algorithm;3) The simulation system is built to verify the proposed method. The simulation results show that the particle swarm fuzzy-PID algorithm can improve the system’s performance greatly compared with PID and fuzzy-PID controller.Thirdly, the45degree oblique axis mount is used as the experiment platform in laboratory environment. The software and hardware of the control system is designed to verify the proposed control method. The design detail of each functional module is given, such as the controller, power circuits, the motor driving module, the image acquisition module and the wireless communication module.Finally, based on the designed DSP2812oblique axis mount drive system platform, the mount servo control system is respectively controlled by PID control, fuzzy-PID control and particle swarm fuzzy-PID control to track the sun. Then the control effect of various control algorithms is analyzed contrastively. The experimental results show that compared with PID and fuzzy-PID, the particle swarm fuzzy PID controller can further accelerate the response speed of the system and improve the stability of system.