Abstract
This paper presents both simulation and experimental investigation into the simultaneous design of a steering wheel and its control system for vibration suppression. The research can be divided into two stages. In the first stage, the simultaneous design is formulated as a nonlinear programming problem in which the H∞ norm of the closed-loop system is minimized with respect to the structural parameters and the control parameters. For the convenience and efficiency of using existing control design tools, the original formulation is replaced by a nested one in which only the structural parameters are used as explicit design variables in the main optimization and for a given structure, a sub-optimization is carried out to find the corresponding optimal control parameters. The design obtained by simultaneous optimization is compared with the original structure combined with the corresponding optimal controller and the effectiveness of the simultaneous optimization is verified by simulation. In the second stage, experiments are performed to evaluate the design of simultaneous optimization. For simplicity, standard H∞ control is used in the first stage and the effects of modeling error and system uncertainty are not considered. However, dealing with these factors is important issue in a real structure-control system. Since μ synthesis is a systematic robust control method to analyze and quantify the effects of uncertainty, it is adopted in the experimental evaluation. The experimental result shows that the optimized structure is still superior to the original one after the controllers are redesigned in the framework of μ synthesis.
