Stability and performance robustness of manipulators

A method for the synthesis of robust controllers of manipulators is described. The emphasis is on the design of control systems in the presence of uncertainties. The sources of uncertainty are parameter errors as well as unmodeled dynamics and non-linear effects. The closed-loop system is to remain stable and performance robustness specifications are to be achieved despite model uncertainties. Stability and performance robustness measures are derived which are functions of frequency. Given a linear model for the manipulator, and a bound on model error, these measures evaluate various control system designs and enable the designer to determine (for a given design) whether stability and performance robustness specifications can be guaranteed in the presence of model uncertainties. The results are applied to a 2 degree-of-freedom spatial manipulator.