Accurate Decoupled Linear Modeling for Robust H_∞ Control of Multi Axis Shaking Tables

This paper illustrates an improved linear modeling method for multi axis electro-hydraulically actuated servo systems to enable the design of high performance and robust H_∞ controllers. The model is validated for a Multi Axis Simulation Table (MAST) located at the University of Bath. The dynamic analysis of the MAST proves the effectiveness of the modeling technique compared with conventional methods. Based on the validated linear model, the uncertainties of the system, as determined from parameter estimation errors and system nonlinearities, are quantified. This leads to the design of an H_∞ controller for the MAST. The simulated performance of this controller is then compared with that of a classical PI controller. In this paper, the control potential is demonstrated for horizontal table motion.