Output-Feedback Speed-Tracking Control Without Current Feedback for BLDCMs Based on Active-Damping and Invariant Surface Approach

With the proposed technique, a controlled brushless DC motor can robustly track the desired trajectory, while estimating angular acceleration, to remove current feedback. The controller design task does not require true motor parameters and load information using the standard disturbance observer design approach. The first feature is that a parameter-independent angular acceleration observer is devised to avoid direct differentiation of the speed measurement. The second one is that active-damping pole-zero cancellation control stabilizes the surface, thereby describing the desired first-order tracking system dynamics. The prototype 50-W BLDCM control system experimentally evaluates the speed-tracking and positioning performances.