A new fuzzy control system based on the adaptive immersion and invariance control for brushless DC motors

In this study a novel type-2 fuzzy control approach on basis of the adaptive immersion and invariance (I & I) control method is proposed to control of brushless DC motors (BLDCMs). The parameters of the mathematical model of the BLDCM are considered to be unknown and furthermore the dynamics of BLDCM are disturbed by changes of some variables such load torque and phases resistance. The stability is analyzed based on the adaptive I & I theorem and some tuning laws are derived for uncertain parameters. Furthermore, the approximation error is tackled by the proposed fuzzy compensator. The parameters of the fuzzy compensator are tuned through the Lyapunov stability method. The reference signal tracking performance of the suggested control technique is examined in three cases. In the first case the load torque and phases resistance are constant, in the second case the phases resistance is considered to be time-varying and the load torque is abruptly changed and finally in the third case, a comparison with some other well-known control techniques is taken to account. It is shown that the proposed controller results in desired performance.