Robust adaptive speed control of disturbed brushless direct current motor

We proposed two adaptive control methods for speed control of brushless direct current(BLDC) motor disturbed by two kinds of disturbances in this paper. The dynamic model of BLDC motor possessing either parametric uncertainties disturbed by unknown with known bound external disturbances or parametric uncertainties disturbed by unknown with known structure model external disturbances is considered, respectively. With the prior knowledge of the parametric uncertainties and the bounded functions of external disturbances of BLDC motor, a robust adaptive control method based on backstepping is designed firstly; For the BLDC motor model with parametric uncertainties disturbed by external disturbances with known structure model, an adaptive control method combined with disturbance observer is proposed. The proposed two methods preserve the advantages of adaptive control and robust control and guarantee transient performance with prescribed precision of robust control for the systems with both parametric uncertainties and unknown disturbances. The resulting controllers are more flexible than either adaptive control or robust control, and the rotor speed of BLDC motor can track its desired value with satisfying performances. Simulation results verify the effectiveness of the proposed methods.