Study Of Control Algorithm For Auto-docking System Of Propellant Connector Based

Automatic docking technology of connector is the key technology in the process of rocket launch.Many accidents occurred in the process of propellant filling,which lead to the failure of rocket launch in history.Besides,this technology can significantly improve the efficiency of rocket launch so that it has great economic and safety benefits.Therefore,it highly valued by the world’s aerospace powers.With the heavy development of launch,the increase ofintegration level in connector and the docking environment becoming more and more hostile,conventional PID controller is gradually difficult to meet the control requirement of connector automatic docking system.In order to adapt to the development trend of launch vehicle,it is necessary to find a controller with better control performance,which has positive significance for protecting the rocket body from tearing and improve the safety and reliability of propellant filling process.Firstly,in this paper,the simulation model of automatic connector docking system is established on the platform of Simulation X,which simulates combined with MATLAB/Simulink,as well as compares with the control situation of real system.The simulation results of Simulation X platform are the same as those of co-simulation,which shows that they are equivalent and can be analyzed on the co-simulation model without deviation due to code conversion.The comparison with the actual control situation model is highly similar to the actual system.Secondly,the anti-interference ability of the conventional PID controller is insufficient,and the application in the actual system has reached the bottleneck,so it is difficult to improve the control accuracy.Combined with the advantages and disadvantages of fuzzy PID controller,adaptive controller and active disturbance rejection control,are designed respectively.Combined with the simulation model,the simulation is carried out under the interference of noise,wind speed 10m/s,wind speed 15m/s and wind speed 20m/s.The simulation results show that the fuzzy PID control has strong anti-interference,but the improvement of control accuracy is not enough;the control accuracy of adaptive controller has improved significantly,and contains a certain degree of anti-interference;the control accuracy ofactive disturbance rejection controller is slightly higher than that of conventional PID controller,and the anti-interfence performance is also considerable,but it has limited ability for suppressing the influence of the interference by ESO.Combined with the simulation performance of the three controllers and the actual docking situation,it shows that the adaptive control in the connector automatic docking system has good expected effect.Lastly this paper tests by PID controller and adaptive controller on the automatic docking system.It tracks to the target which can make static motion、sinusoidal motion、constant amplitude and frequency conversion motion、exponential decay motion and variable amplitude and frequency conversion motion.The test is approximate to the simulation results.Adaptive controller is greater than PID controller at tracking precision、anti-interference capability and overshoot,and it can be better at improving control performance,which can provide important support for the development of connector integration and the heavy development of launch.