SLIDING MODE CONTROL OF ROBOTIC MANIPlILATORS
The application of sliding modes in robotic manipulator motion control is presented in this paper. The structure of the control system is intentionally selected to resemble 011 the cascade systems in order to apply digital signal processiiig for iniplementatioii into the Variable Structure Systems (VSSf with sliding modes. First the mathematical description of robotic manipulators powered by electrical machines is derived in a form suitable for sliding modes application. Then equations of motion under a sliding mode are derived and the selection of the outer loop controller is presented. The following problems are discussed: the selection of the switching functions in a form that allows the clear separation on the fast and slow motioii of the system; the design of a cascade VSS with an inner current loop and the influence of paranieters uncertainties on the system motion. The proposed algorithms are verified by. simulation and experiments. Both siniulation and experimental resul ts are presented.