Fast and accurate speed regulation of brushless DC motor servo systems via robust composite nonlinear control

A parameterized design of speed servo controller for brushless DC motors is presented based on a robust composite nonlinear control framework. The servo controller consists of a linear control part for achieving fast response, a nonlinear feedback part for suppressing the overshoot, and a disturbance compensation mechanism for erasing the steady-state error. A reduced-order extended state observer is adopted to estimate the un-measurable state variables and unknown disturbance. Simulations are first carried out in MATLAB/Simulink, followed by real-time experiment using a TMS320F28335 digital signal controller board. The results confirm that the proposed control scheme can achieve fast, smooth and accurate tracking of target speed, and has a good performance robustness against the load disturbance and parameter variations.