Research On Speed Tracking Control Algorithm Of Maglev Train Based On Improved Active Disturbance Rejection Controller

As a new mode of rail transit,maglev train is an important support for realizing the strategy of China's transportation power.With the rapid development of control theory and artificial intelligence technology,the operation of maglev trains has become more intelligent.Among them,the speed tracking system of maglev trains is an important basis for realizing the automatic operation of trains.However,the characteristics of large time delay,nonlinearity,and multiple constraints in the train operation process make the automatic control of the train very difficult.In view of the above characteristics,it is of great significance to study a simple,effective,stable and reliable speed tracking control algorithm for the safety,energy saving,punctuality and other requirements of the automatic operation of maglev trains.By studying the dynamic model of the maglev train,this paper analyzes the speed tracking control strategies proposed by domestic and foreign scholars,and studies the speed tracking control algorithm of the maglev train according to the large time delay characteristics of the train running process.The main work of the paper is summarized as follows.First,the force analysis of the operation process of the maglev train is carried out,and the dynamic model of the maglev train is constructed.The time-delay link in the train speed tracking system is equivalent to a second-order inertial link,combined with the active disturbance rejection control theory,a third-order Linear Active Disturbance Rejection Controller(LADRC)is proposed.Modular design is presented,and finally,based on the structure of the controller,the control principle of the controller is systematically discussed.Second,based on the structure of LADRC,an improved ADRC(Time-Delay-ADRC,TDADRC)is proposed.Firstly,the control structure of TD-ADRC is given;secondly,the transfer function of the train speed tracking system is systematically analyzed,and some transfer functions are equivalent in the low-frequency domain;thirdly,based on the equivalent transfer function,the first order plus time delay(FOPTD)model is proposed;fourthly,based on the FOPTD model,the parameter tuning strategy of the controller is given;fifthly,the train speed tracking system is controlled by a single degree of freedom control structure.It is converted into a 2-DOF control structure,and based on the 2-DOF control structure,the stability of the system is analyzed,and then the parameter domain of the controller that satisfies the system stability is solved.Third,in the Simulink environment,a maglev train speed tracking system is built,the ability of LADRC and TD-ADRC to track the target speed curve is verified successively,and the anti-interference ability of the maglev train speed tracking system based on TD-ADRC was analyzed.The simulation results show that(1)Compared with the Proportion-IntegrationDifferentiation(PID)controller,the speed tracking system of the maglev train based on the LADRC controller reduces the tracking steady-state error,but the system output still has a certain Oscillation,which shows that the LADRC controller improves the tracking accuracy of the train,but the ability to reduce the influence of the time delay link needs to be improved.(2)The TD-ADRC controller can make the maglev train track the target speed curve stably and accurately in different sections,effectively reducing the influence of the time-delay characteristics on the system,which is of great significance to the automatic operation of the maglev train.