Research on Real-Time Monitoring and Performance Optimization of Suspension System in Maglev Train

With the success of the commercial operation of the maglev train, the demand for real-time monitoring and high-performance control of the maglev train suspension system is also increasing. Therefore, a framework for performance monitoring and performance optimization of the maglev train suspension system is proposed in this article. This framework consists of four parts: plant, feedback controller, residual generator, and dynamic compensator. Firstly, after the system model is established, the nominal controller is designed to ensure the stability of the system. Secondly, the observer-based residual generator is identified offline based on the input and output data without knowing the accurate model of the system, which avoids the interference of the unmodeled part. Thirdly, the control performance is monitored and evaluated in real time by analyzing the residual and executing the judgment logic. Fourthly, when the control performance of the system is degraded or not satisfactory, the dynamic compensator based on the residual is updated online iteratively to optimize the control performance. Finally, the proposed framework and theory are verified on the single suspension experimental platform and the results show the effectiveness.

Study on the effect of dimple position on drag reduction of high-speed maglev train

Transient numerical simulations were carried out by placing dimples at the top, sides and bottoms of the tail car streamline area of a high-speed maglev train. The results of an improved delayed detached eddy simulation turbulence model using three-dimensional compressible Navier-Stokes and shear-stress transport K-Omega double equations were compared to the results of a wind tunnel test to verify the numerical simulation accuracy, within 5% of the ground truth, which is an acceptable precision range. The results show that dimples arranged on the streamline area atop the train tail car affected the locations at which the airflow at the top and bottom of the train met and weakened the strength of the wake. The aerodynamic drag and lift coefficient decreased by 3.40% and 4.27%, respectively. When the dimples were arranged on the streamline area at the sides or bottoms of the train tail car, they had little effect on the top of the tail car, so they did not destroy the balance of the airflow at the top and bottom. They also had little influence on the development of wake topology. Therefore, the aerodynamic drag and lift of the train changed little.

Research on Siding Mode Controller of High-Speed Maglev Train Under Aerodynamic Load

The high-speed maglev train will be subjected to extremely obvious aerodynamic load during operation, it will also be subjected to instantaneous aerodynamic impact load in the case of passing, which will bring extreme challenges to the suspension stability and safe operation of the train. It is necessary to consider the influence of aerodynamic load and shock wave in the design of suspension control algorithm. Traditional proportion integration differentiation (PID) control cannot follow the change of vehicle parameters or external disturbance, which is easy to cause suspension fluctuation and instability. In order to improve the suspension stability and vibration suppression of high-speed maglev train under aerodynamic load and impact, a controller based on sliding mode technique is designed in this paper, and in this controller, the deformation of the primary suspension is introduced to replace the aerodynamic load on the electromagnet. In order to verify the control performance of the designed controller, the dynamic simulation model of train with three vehicles is established, and the dynamic response of the train under the condition of passing in open air is calculated. Compared with the PID controller, it is verified that the sliding mode control (SMC) method proposed in this paper can effectively restrain the electromagnet fluctuation of the train under aerodynamic load.

Auxiliary Stopping Area Layout Method for High-Speed Maglev considering Multiple Speed Profiles and Bidirectional Operation

Auxiliary stopping area (ASA) is the key guarantee for high-speed maglev train operation safety. Aiming at the layout of the ASA along the track, this article constructs an optimized model of ASA layout and proposes a solving algorithm based on the single target genetic algorithm by analyzing the influence factors of ASA layout. The result of the numerical experiment shows that the proposed method could fulfill the requirements of the maglev train operation safety and efficiency and optimize the cost of the ASA layout while taking the complex line situation, train tracking operation, and bidirectional operation on a single line into account.

Dynamic Response Analysis of Medium-Speed Maglev Train with Track Random Irregularities

In order to analyze the dynamic response of medium-speed maglev train in the speed range of 0–200 km/h, the suspension performance, suspended energy consumption, and riding comfort of the train stimulated by random track irregularities are discussed in this paper. Firstly, the model of medium-speed maglev train including car body, air spring vibration isolation system, and the suspension system is established. Then, a controller based on flux inner feedback loop and PID outer feedback loop is designed for the suspension system. The established model is stimulated by the actual track power spectrum in full speed range. The simulation results show that the fluctuation of suspension gap is less than ±4 mm. Furthermore, thanks to the adding of permanent magnet, the power consumption is significantly reduced, which is of benefit to the electromagnet heating problem and on-board levitation power supply system. The riding comfort of the train moving on the irregular track using Sperling index is assessed. The experimental results validate the effectiveness of the proposed analytical calculation model of medium-speed maglev train. It is shown that medium-speed maglev train achieved good performance, significant power reduction, and satisfactory riding comfort.