The suspension system of Maglev vehicle needs strong robustness and anti-jamming ability in the process of operation and fluctuation control. In order to solve the open-loop instability and strong nonlinearity of the mechanical equation of the suspension system of the Maglev vehicle, the non-linear dynamic equation is established. At present, the research based on the single electromagnet and the rigid track is the most common. However, based on this method, it is impossible to study the coupled vibration caused by track factors. Therefore, based on the dynamic equation of a single span simply supported beam of flexible track and the non-linear equation of the suspended electromagnet itself, an overall control model is needed to discuss the control strategy. Based on this dynamic model, the singularities of the system are solved according to Hurwitz criterion, and the characteristic equation corresponding to the Jacobian matrix is obtained. The stability analysis shows that the system is unstable. At the same time, the necessity of using a feedback control method to control the air gap has been proved. On this basis, a sliding mode adaptive state feedback controller for the maglev system is designed based on the RBF network approximation principle. The corresponding simulation and experimental results are given. The simulation and experimental results show that the controller can ensure the vehicle's stable suspension and effectively suppress external interference. Compared with the traditional PID and fuzzy controllers, the controller can guarantee a faster dynamic response, stronger robustness, and smaller overshoot while considering the flexible track and external disturbances. INDEX TERMS Maglev system, flexible track, coupled vibration, RBF, sliding mode adaptive control.
Due to the strong coupling and large disturbance between multiple electromagnetic coils, the previous dynamic model of low-speed maglev train cannot accurately model the complex system when it is levitated. Therefore, based on the general linear transfer function, the concept of feature modeling is introduced to describe the dynamic characteristics, environmental characteristics and control performance requirements of the system by defining feature variables. On the premise of satisfying a certain sampling frequency, the original dynamic model is approximately linearized, which is equivalent to a second-order difference equation, i.e. a system with slow time-varying parameters. On this basis, the design and implementation of the controller of the magnetic levitation system are discussed. First, by studying the application of PID controller in suspension system, the difficulty of parameter debugging of PID controller and the insufficiency of restraining coupling interference are pointed out. The generalized predictive control (GPC) is proposed and improved to improve the robustness and anti-jamming of the system. Finally, a large number of simulations and experiments show that the controller can effectively suppress the coupling interference. Compared with single-point levitation controller, it has higher application value in engineering practice.
In order to analyze and verify the adaptability of train to track beams with different stiffness, the dynamic response of vertical vehicle-track-bridge with different stiffness track beam is studied. Firstly, according to the actual vehicle-track-bridge coupling system, the corresponding mechanical and kinematic equations are established. The natural vibration characteristics of track beams (bridges) with different stiffness are studied, and the dynamic response caused by current control algorithm is analyzed. Secondly, combined with the 3-D model of vehicle-track-bridge and the actual system, the dynamic simulation and experiment of the coupling system of track beam with different stiffness in the speed range of 60 km/h are carried out. The results show that the vertical first-order natural frequency of track beam decreases with the decrease of track beam stiffness. When the deflection span ratio increases, the suspension gap fluctuation increases, but the increase of deflection span ratio within a certain range will not affect the tracking performance of control current, and the train is still in a relatively stable suspension state. For the track beam, with the decrease of stiffness, the vertical deflection of the track beam increases and the high-frequency vibration energy increases, which has a great impact on the vibration response of the coupling system. The research results of this paper can provide a useful reference for the optimization of suspension system of medium and low speed maglev train, line design, and the formulation of construction standard of maglev vehicle-track-bridge system. In addition, the research results of this paper can provide a theoretical basis for reducing the construction cost of track beam.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.