Robust adaptive control of direct drive brushless DC motors and applications to robotic manipulators

Application of robust adaptive nonlinear control to brushless DC motors is considered in this paper. The advocated robust adaptive controller enjoys robustness to parametric and dynamic uncertainties in the motor dynamics. In addition, the controller can reject any bounded disturbances acting on the motor. The controlled variables are phase voltages which are designed based on the backstepping technique. The closed-loop stability of the system is shown using Lyapunov techniques. The tracking errors are shown to be globally uniformly bounded. The design procedure is shown to be also applicable to multi-link manipulators actuated by brushless DC motors. The control design may be improved to achieve asymptotic tracking.