Research On The System Identification And PID Auto-tuning Technology Of Large Gear Measuring Center

Large gear is widely applied in wind power, ships and large machines. Large gear measuring center is a comprehensive and key measuring equipment to implement accuracy measurement of large gears. Large gear measurement is facing some difficulties such as error compensation, wide measuring rand, large load variation and so on. These problems has been the obstacles in the research of gear measuring instruments. There is no major breakthrough in China for a long time. In this paper, aiming to solve the problem that the dynamic performance are becoming worse for the inertia change, the method research and experiment verification are carried out, which lays the foundation for the control of the large gear measuring center and the perfection of the software system.This thesis introduced the mechanical system of T150 gear measuring center which is developed by Harbin Tonghe Optics and Precision Machinery Co. Ltd. Based on the electrical and mechanical system of rotary axis, transfer function were induced. Applying the PMAC, the control system of rotary axis in T150 gear measuring center are constructed.On the basis of the research in system identification and PID tuning methods. Considering the large scale inertia of T150’s rotary axis, the online identify scheme using the least squares estimation system identification method are introduced. Based on the result of system identification, the particle swarm optimization method for PID tuning are introduced.Lastly, the experiments are based on T150 large gear measuring center. Through the step respond of the position loop. Using the least squares estimation method to identify the transfer function’s parameters of the rotary axis. Through the open loop respond of electric machine, using the least squares estimation method, the validity of the method are proven. Based on the result of system identification, using the particle swarm optimization PID tuning method, the PID’s parameters of T150 are obtained. Setting the parameters into the PMAC, the dynamic performance of servo system are enhanced. The parameters of the control system are accurately tuned according to the change of inertia of rotary axis by the system identification and PID tuning method used in the paper.