Hardware/software implementation of PI/PD-like fuzzy controller for high performance motor drives

PI/PD-like fuzzy controller is proposed for control of high performance motor drives. The system utilizes two fuzzy logic (FL) structures to generate a control signal. The first FL mimics PD control and generates an explicit output. The second FL acts in parallel to mimic PI control and generates an incremental output which adds to a previous PI control signal to create an updated PI control signal. The fuzzy PI- and PD-type controllers are combined to cope with different operating conditions. Saturation protection exists before passing the control to the motor drive. A filter creates a reduced noise feedback error signal, and a difference creates a delta error signal between the present filtered error and that of the previous time step. These two inputs feed both FL structures. The rules for both the PI and PD FL structures are given with explanation of the physical meaning. The PI/PD-like fuzzy controller is implemented in MATLAB/Simulink and loaded onto a dSPACE DSP. A suite of tests examines robust control performance under various operating conditions. Experimental results have shown that the fuzzy PI- and PD-Type controllers robustly respond to a wide range of operating conditions.