Automatic Hot Test Technology Of Gyrotron Traveling Wave Tubes Based On The Robust PID Feedback Control

Gyrotron travelling wave tubes(gyro-TWTs)has played a very important role in many applications such as radar detection,millimeter wave communication and electronic countermeasures.However,high stability of output power of gyro-TWTs during an extremely long operation time(several hours)is expected in these applications.In addition,hot test is an essential part in the producting process of gyro-TWTs,and the remote control platform of the high-power gyro-TWTs hot test was set up in our laboratory,which can reduce the manual operation of all equipment in the testing process and improve the test efficiency.But there still needs some manual operation in the testing process and automatic test of gyro-TWTs is not achieved.Therefore,in order to achieve automatic test of gyro-TWTs and ensure the stability of output power,it is necessary to develop an automatic test software adopting double robust PID control strategy to realize the automatic feedback control of the system and improve the stability of the output power.Using the software instead of people to operate the remote control platform can ensure the stability and reliability of the test system,and the automation of the test platform is also realized.The main research contents of the paper are as follows:(1)Several PID parameter tuning methods are compared from the given value output response,robustness and anti-jamming ability,and a proper method is selected according to the characteristics of hot test of gyro-TWTs.(2)By analyzing the functional requirements of the test system and the control parameters,a double robust PID control strategy is proposed to ensure the stability of output power: a PID feedback control on the voltage for direct stabilization of output power and an additional PID control on the heater current for stabilization of beam current.(3)The simulation of the PID control on voltage rise process and voltage maintenance process are conducted respectively.For the voltage rise process,we analyze the reason of the deviation between simulation and experiment result,and a satisfactory simulation result is got according to the analysis results finally.For the voltage maintenance process,PID responses after feedback control with sinusoidal and random fluctuations are respectively investigated and the influence of parameter variation of sinusoidal voltage fluctuation on PID feedback control effect is analyzed,and according to adjusting the relevant parameters and strategies,an effective stability control of these two kinds of voltage fluctuations is achieved.(4)The mathematical modeling for voltage and current control process in the hot test system is carried out.We improve the general step response modeling method by traversing the time constant on the basis of the original model,and precise mathematical models of control curves of voltage and current are established according to the improved method finally.(5)The code of the automatic test software is completed,and then the virtual debugging and actual debugging of the software are accomplished,and the actual control effect of the software is analyzed.The innovation of this paper mainly includes the following points:(1)According to the control requirements of the hot test of gyro-TWTs,a robust multi feedback PID control scheme is proposed to control the operation voltage and the beem current,so as to achieve the long and stable output power of gyro-TWTs.(2)Since the hot test of the gyro-TWTs has a certain risk,the robust PID control process of working process of the gyro-TWTs is simulated before using the automatic test software to test the tubes,and the validity and reliability of the PID control strategy are verified in advance.(3)In view of the characteristics of the test control system of gyro-TWTs,the general step response modelling method is improved,and then the mathematical models are established for the control process of the voltage and current of the gyro-TWTs,which greatly improves the precision of the models.