Study On Communication Network Of Location And Speed Detection System For High Speed Maglev Vehicle

To detect the location and speed of high-speed maglev (magnetically levitated) vehicle, a location and speed detecting scheme was proposed, the tooth-and-slots of LSM (linear synchronous motor) and the location reference leaves beside the track are detected as the relative and absolute location signals, respectively. In this dissertation, the structure and function of system, the performance requirements of system and the characteristics of communications network were analysed objectively. Then a detailed communication scheme was proposed, including design and realization of the hardware and software.SPI synchronous communication was adopted to connect tooth-and-slots sensor and PRW maglev pole angel electronic unit, transmiting pole angle information. Asynchronous serial communication was adopted to connect absolute location unit and ORT location electronic unit, transmiting 12 bits location coding. PRW maglev pole angel electronic unit and ORT location electronic unit using CAN fieldbus to exchanged information for calculating actual location and speed of maglev vehicle. The ORT location electronic unit provide location and speed information to vehicle safe computer by 20mA current loop, which was for vehicle monitor and safe protection. The PRW maglev pole angel electronic unit provide location and speed information to vehicle wireless transmiting unit by RS-485 synchronous communication ,which was for feedback control of long stator linear synchronous motor.Vehicle diagnose computer connected both of electronic units by CAN fieldbus, which was for fault detection and analysis of vehicle location system.Considering the actual work circumstance of location system, a sensor redundancy design and self-diagnostic scheme was proposed, the experiments showed that proposed scheme was feasible.Finally, a analysis result was given and relevant solutions were provided.