Implementation of an adaptively scaled fuzzy controller for DC drives

A real time implementation of both PI and fuzzy controllers is conducted on a microcomputer controlled separately excited DC drive. The experimental results show a good tracking performance of the two controllers, with a slight advantage of the fuzzy controller, at different operating points. Whereas, under load disturbance, the fuzzy controller gave a remarkable regulating performance. To minimize the steady state oscillatory performance, that appears at low speeds, the fuzzy controller must be provided with an adaptive scaling of the input and output universes of discourse that depends on the absolute value of the error.