Synthesis of a high-speed tracked vehicle suspension system--Part I: Problem statement, suspension structure, and decomposition

This two-part paper is concerned with the problem of synthesizing a high-speed vehicle suspension system. Using a new decomposition technique, it is shown that there exists an optimal structure which a high-speed suspension must have in order to fulfill the requirements of vehicle body vibration isolation within given displacement constraints, external force cancellation, vehicle body tilting and guideway tracking while maintaining primary gaps or contact forces within given limits, and assuring maintenance of nominal mass and inertia parameters of the vehicle body. The suspension structure derived in this part is such that the incompatibility of vibration isolation and guideway tracking under the influence of external forces which is present for all suspensions synthesized heretofore-whether optimal control approaches have been used or not-has been removed. The new suspension structure features three independent parts: the nonlinear and time-varying preload-and-mass control operating on external forces and vehicle body accelerations, the linear time-invariant tracking control operating on the means of certain vehicle states, and the linear time-invariant vibrating control which operates on the difference between the actual vehicle state vector and its mean.