Research On Design And Control System Of PTZ Multi - Point Measurement

Currently single-point measurement of snow depth can not fully reflected snow depth in the high-speed railway track, multi-point o measurements of snow depth based on PTZ (Pan-Tilt-Zoom) can make up for the lack of single-point measurement. Aimed at multi-point measuring snow depth performance requirements, this study was designed to develop servo control system two degrees of freedom of PTZ based on DSP, which used fractional order controller to control its rotation precision and make PTZ have strong robustness to load change. The main work is as follows:According to the functional requirements, the critical subsystems PTZ was analyzed. The suitable driving mode and transmission mode was selected. The mathematical model of brushless DC motor was established; The D-H method was used to analyze the kinematic position of PTZ. At last the PTZ control protocol was determined.PTZ mechanical structure was detailedly designed. Firstly layout of each part based on the PTZ with a transmission structure were determined, the PTZ motion work principle was analyzed, The encoder the connecting shaft and the level of organization and the pitch mechanism profile was designed. Finally a prototype was produced.The PTZ control hardware was designed based on DSP which mainly includes a drive circuit, power supply module, the external interface circuit, position sensor unit design, external expansion SRAM circuit, serial communication circuit. Finally, PTZ control hardware panel was produced.The control performance of PTZ movement system was mainly researched based on fractional order controller. Firstly fractional basic theoretical knowledge was introduced. The impact of fractional order parameters and tuning methods was analyzed; Then fractional order controller was applied to simulate brushless DC motor system model, making the track step signal, ramp signals and the robustness of the simulation test. The results show that the fractional order control were high precision, robustness, meeting PTZ motion control performance requirements.