Quantitative Synthesis to Tracking Error Problem Based on Nominal Sensitivity Formulation

This brief presents a simple and robust design technique based on quantitative feedback theory (QFT) to solve the tracking error specification (TES) problem. The TES problem is converted into an equivalent disturbance attenuation (EDA) problem wherein the plant uncertainties are translated into equivalent external disturbance sets. The design problem then becomes a simple nominal disturbance rejection problem. The main advantage of the proposed technique is that they are simple, computationally efficient, and require less control effort (overdesign) due to the nominal sensitivity function formulation. The computational simplicity of the proposed methods makes them potentially more suitable for handling design problems involving a large number of uncertain plant parameters. Experiments are conducted on a laboratory electro-mechanical plant emulator system to demonstrate the efficacy of the proposed design method.