A control design for a tracked vehicle with implicit nonlinearities using quantitative feedback theory

A vehicle speed-control system is developed for the M113 tracked vehicle. Because the nonlinearities involved are implicit in the model, it is difficult to apply most currently available techniques. However, quantitative feedback theory (QFT) offers an alternative solution to this complex control design problem. The main idea of QFT nonlinear control design is to design one robust controller for an equivalent family of linear time-invariant models of the nonlinear system to be controlled. The equivalent linear time-invariant system set has input-output behavior similar to that of the nonlinear system in the desired operation range. The robust controller is designed to ensure that every member of the equivalent set would perform well as specified. Its performance and validity are further verified through extensive simulations to show satisfactory results