The Technical Research Of Levitation Gap Sensor In High-speed Maglev Vehicle

As a new vehicle, High-speed Maglev Vehicle (HSMV) has the advantage of high velocity, less energy consuming, lower noise, safety and comfort, and is fit for high-speed transport. In HSMV, the levitation system plays an important role, and the gap sensor is also critical. In order to solving engineering problem of the HSMV-gap sensor, this paper investigates the temperature drift, communication interface and fault location technique during the course of assembly and maintenance.Firstly, the temperature varies in a large range in the place where the gap sensor works, so this paper analyzes the temperature drift of gap sensor, and finds out that the main reasons which result in temperature drift are the resistance of detecting coil and demodulating circuit parameters. To resolve this problem, a practical design of detecting coil is given, and a compensative measure considering the detecting coil and demodulation circuit is proposed to improve the temperature stability of gap sensor.Due to high speed of the Maglev, it demands rapidity and reliability of the communication interface between gap sensor and suspense control system. Thus a multi-serial asynchronous communication interface based on RS-485 is designed. It transmits one signal on each unattached channel and has redundant structure, which meets the requirement of rapidity and reliability. The gap sensor works in a complex electromagnetism place and there is much disturbance, so it is likely to result in communication failed. This paper analyzes the disturbance which may fail the communication, and brings forward corresponding resolving method.Moreover, due to the complexity of the structure of gap sensor, it is easy to work out in the course of using. Because of the large number of gap sensor, the service workload is very large, and the fault location needs a long time, and costs too much. To solve these problems, this paper gives the gap sensor's fault model, finds out the weaknesses, and designs a BIT fault detecting system which is tested by experiment, improving the maintenance efficiency.