Model Decoupling of Electromagnetically Levitated Vehicle

Abstract

The electromagnetically levitated vehicle moves along the rail, supported by attractive force of electromagnetics. This support system is inherently unstable and requires closed loop control for levitation gap. This control equipment is important to the vehicle implimentation and it must be designed by the specification of responce to the disturbances. This disturbances are assorted to two classes, one is rail arrangement disturbance which the vehicle ought to follow without offset and the other is external force disturbance.
Up to this time analysis and synthesis of this control system has been carried out based upon mainly one magnet system. This is incomplete when we extend to one vehicle model which consists of two bogies and one vehicle body, because the bogie and vehicle body have six freedoms of motion, which are heave, roll, pitch, twist, sway and yaw. Therefore the control system is a multi input-output and multivariable system. We allocated these freedoms into two subcontrol systems. One is support system and the other is guide system. These two systems can be treated equally.
Support system, which we take up, is decomposed by modes of motion in the model, and it is shown that not only input-output relations but also state variables and each disturbance can be decomposed into four decoupling modes which are correspond to four freedoms of motion in support system. We easily analize the vehicle responce to each disturbance in this decoupled mode. Other basic characteristics will be also shown by this useful decomposition theory such as the mode transfer between bogie and body.