Research On Digital Control Technology Of MAGLEV Vehicle's Suspension System

Suspension control is the key technology of maglev vehicle research. The dissertation mainly studies the digital control problems on suspension subsystem of EMS maglev vehicle. Decoupling ability of vehicle bogie was first analyzed to prove that suspension module is the independent control unit, followed by calculation of magnetic forces based on distributed magnetic field model. After that, decoupling control algorithm about suspension module was studied.Its main contents comprise the following aspects.Firstly, the structure decoupling analysis of a magnetic bogie is presented. Bogie is the basic sustaining unit of EMS maglev vehicle, yet its kinematics decoupling has not been completely solved. The dissertation simplifies the system model by means of inner DOF(degree of freedom),and sets up the kinematics of a magnetic bogie. Analytical form of the inversed solution to kinematics equation is then given. This solution extends former conclusions about the structure analysis, and has a significant role in structure decoupling analysis and vehicle design.Secondly, calculation of magnetic forces based on distributed magnetic field model is presented. Magnetic forces formula usually used in maglev system research is based on point model, which differs evidently where magnet is not parallel to the rail. The dissertation for the first time studies the analytical form of magnetic force when pitching angle between magnet and rail is not zero, and proves its validity by means of FEM analysis.Thirdly, stability analysis of single magnet suspension system by means of Volterra operator is presented. The work on stability analysis of nonlinear suspension system is singularly. This dissertation takes the advantage of Volterra nonlinear system stability theory to set up the stability criterion of single magnet system controlled by PD algorithm.At last, two-point decoupling control algorithm of suspension module is presented. Suspension module is a rigid body, so independent control structure for its each end is not proper, especially when its ends swing hard. Here suspension module is modeled as a whole object, and a decoupling control algorithm is presented, which is proved correct via simulation.