ABSTRACT
The precise position control of a brushless direct current motor (BLDC) is a more complicated problem due to the multi-input nature of the motor and the significant nonlinear coupling among its phase winding currents and the rotor velocity. This chapter applies the adaptive integrator backstepping tools to the design of a position tracking controller for the BLDC motor. Since the BLDC motor is a three phase machine, the standard, fixed rotor transformation is utilized to substantially simplify the nonlinear electromechanical dynamics. The motor is viewed as a torque source and thus a desired torque signal is designed to ensure that the load follows the desired position trajectory. Since the developed motor torque is a function of the electrical winding currents, a simple commutation strategy is utilized to restate the desired torque signal as a set of desired current trajectories. Based on the exact model knowledge of the full state feedback, the position tracking controller is designed for the open-loop dynamics.
