Study On Temperature Control System Of Blackbody Radiation Source Based On Fuzzy Internal Model PID

Blackbody radiation source is a key instrument for radiation temperature measurement and traceability.At present,the common temperature control algorithm for blackbody is PID.However,with the expansion of the application range and the improvement of temperature control requirements,the conventional PID control algorithm has been unable to fully meet the needs.In addition,the temperature control process of black-body radiation source is a complicated process with pure time delay and nonlinearity,so this paper analyzes the temperature control system of black-body and improves its temperature control algorithm to meet higher practical needs.The research object of this paper is the blackbody of the surface source.The research on temperature control of it is divided into the heating process when the target temperature is higher than the ambient temperature and the cooling process when the target temperature is lower than the ambient temperature.Firstly,the basic structure and performance requirements of the blackbody of the source are introduced.Then,the heating and cooling processes are analyzed and deduced,and parameters are identified by MATLAB.Finally,the corresponding mathematical model of the heating and cooling processes of the blackbody of the source is obtained.Then the conventional PID algorithm and its advantages and disadvantages are described and Simulink simulation research is carried out.Then,the principle of fuzzy internal-modulus PID algorithm is introduced in detail.MATLAB software was used to simulate the algorithm,and the heating and cooling effect curves were compared and analyzed.The simulation results show that the fuzzy internal model PID algorithm has the fastest response,shortest stability time,small overshoot and high temperature control accuracy.In order to verify the practicability and feasibility of fuzzy internal mode PID,based on the NI Compact RIO controller,a temperature control platform for the blackbody of the source at room temperature was built.Using LabVIEW software of PID algorithm and fuzzy internal model PID algorithm is developed,and comparing the heating and cooling processes of the two algorithms,it can be obtained that the fuzzy internal mode PID algorithm has the advantages of high steady-state accuracy,small overshoot and short adjustment time compared with the PID algorithm,which greatly improves the temperature control quality of the blackbody of the surface source.