Fault-Tolerant Control of Magnetic Levitation System Based on State Observer in High Speed Maglev Train

In recent years, the high-speed rail train has achieved great progress, but the wheel–rail relationship and the catenary–pantograph relationship are the bottlenecks to further increase the speed. The maglev train is an entirely new mode of transport without wheels. It takes full advantage of electromagnetic force to achieve active levitation and runs the train by the linear motor. It completely abandons the frictional resistance to speed up over 500 km/h practicably. The redundancy and fault tolerance of the magnetic levitation system, which is considered as the wheels of the high-speed maglev train, play a major role in the safety and reliability of high-speed maglev train. However, due to the failure of sensors and the existence of track seams, the suspension unit often breaks down. The performance of suspension join-structure under the modular redundancy strategy with sensor failure is analyzed and investigated. The investigation carried out by us reveals that the overall performance is unpleasant and the electromagnet fevers seriously. In order to solve this problem, we propose and design the state observer as a solution to construct the fault-tolerant control system. The designed observer is applied to estimate the gap measurement of the fault sensor so that the suspension unit will not fail. Therefore, The fault-tolerant control system based on state observer improves the redundancy and fault tolerance capacity of the magnetic levitation system with sensor failure significantly.