Hybrid fuzzy bang-bang mode controller for electric motor drives applications

This paper proposes a real-time hybrid fuzzy bang-bang (BB) controller for high performance motor drives. The controller consists of a fuzzy-BB controller in parallel with BB-controller. The objective is to develop a nonlinear BB-controller using the fuzzy control paradigm for position control of electric motor drives to achieve an improved motor behavior. In order to combine the advantages of fuzzy-BB and BB-based controllers, a hybrid fuzzy-BB controller is proposed in which the output can either be the outputs of the two, i.e. the fuzzy-BB or BB units being switched as per the absolute error signal. The principle of the proposed control strategy is that to use a BB controller, which performs satisfactory in most cases, while keeping in the background a fuzzy-BB controller, which, is ready to take over the BB-controller when changes such as overshoot and oscillations occur in the drive system. Here, the selection between the fuzzy-BB and the BB-controllers is based on a set of simple rules; oscillations have to be detected by the absolute error. The hybrid fuzzy-BB controller has been implemented on hardware with dSPACE DSP processor, and it is observed that the performance of the controlled BLDC motor drive with the hybrid fuzzy-BB controller is very promising. The results clearly demonstrate that the hybrid fuzzy-BB controller is capable of significantly improving the motor performance under random disturbance and different loading conditions.