Magnetic suspension control systems for the MBB high speed train

The problem of designing the magnetic suspension system for a wheelless train with maximum speeds of up to 500 km/hr is discussed. Special attention is given to the modelling of rigid body and elastic modes as well as magnet dynamics in the vehicle system. Disturbances from curves and grades, which are especially important, wind forces, track tolerances, accelerometer biases and instrument measurement errors are investigated. The paper compares a number of control synthesis techniques. Several design methods, such as decomposition, arbitrary dynamics and linear quadratic optimum control, are applied. The magnetic suspension system posed a number of special problems, such as noncyclicity of the system, and the choice of weighting matrices for high order systems, which had to be solved. The practical realization of the necessary measurement instrumentation, digital controller, magnet drivers and support magnets in the MBB magnetic test vehicle is described. The paper is supported by typical experimental results obtained from runs on the MBB test track in München-Ottobrunn.