Design Of Temperature Control System For Low Temperature Blackbody Radiation Source

The blackbody radiation source is the standard radiant source for the reappearance and transmission of radiance and radiation temperature.It is mainly used for calibration of radiance meter and radiation thermometer and so on.It is a standard instrument to ensure the accuracy and unity of radiance and radiation temperature.At present,the digital PID temperature controller imported from abroad is used on the blackbody radiation source.This kind of PID controller will cause the system temperature to be overshoot and oscillation.The temperature reaches a stable state with long time and poor stability.In order to overcome the shortcomings of this kind of PID controller,this thesis discusses and designs a non-overshoot low temperature blackbody radiation source temperature control system based on Active Disturbance Rejection Control(ADRC)Technique.The main contents are as follows:(1)Simulation design of blackbody radiation source cavity.Design a complete black body radiation source cavity structure.Establish a temperature heat transfer model for the structure,Simulate the temperature change process of blackbody radiation cavity at the unsteady heat conduction process based on finite element analysis method.(2)Establish a blackbody radiation source temperature control model and research the active disturbance rejection temperature control method of black body radiation source.Through temperature control system identification and parameter estimation methods,the temperature transfer model of the controlled object was obtained through experiments.Designs a non-overshoot low temperature blackbody radiation source temperature control system based on Active Disturbance Rejection Control Technique.The temperature control effects of three temperature control methods,including PID control,nonlinear PID control,and Active Disturbance Rejection Control Technique,were compared by simulation.The results show that the Active Disturbance Rejection Control Technique has relatively fast response speed,and the fluctuation of temperature after the system is stable is smaller,with less transition time and non-overshoot(3)Build and test the test platform of low temperature blackbody radiation source temperature control system.Carry out the hardware selection of blackbody radiation source temperature control system,and build the experimental platform.a non-overshoot low temperature blackbody radiation source temperature control system of the Active Disturbance Rejection Control Technique based on QNX platform is carried out.The experimental results show that the non-overshoot temperature control system stability of the blackbody radiation source based on the Active Disturbance Rejection Control Technique is better than 0.01?/10 min,the temperature field uniformity of the blackbody radiation source is at the temperature range of 30~50?,the uniformity of the temperature field of the target surface of the blackbody radiation source is better than 0.05?,and the expected target is achieved.