M. M. Fateh - Electrical Engineering Department, University of Shahrood, Shahrood, Iran.
S. Azargoshasb - Electrical Engineering Department, University of Shahrood, Shahrood, Iran.

This paper presents a discrete-time robust control for electrically driven robot manipulators in the task space. A novel discrete-time model-free control law is proposed by employing an adaptive fuzzy estimator for the compensation of the uncertainty including model uncertainty, external disturbances and discretization error. Parameters of the fuzzy estimator are adapted to minimize the estimation error using a gradient descent algorithm. The proposed discrete control is robust against all uncertainties as verified by stability analysis. The proposed robust control law is simulated on a SCARA robot driven by permanent magnet dc motors. Simulation results show the effectiveness of the control approach.

Discrete Control, Uncertainty Estimator, Free-model Control, Adaptive Fuzzy Estimator, Task-space, SCARA Robot