Auto-tuning technology for fuzzy algorithms based DC brushless servo systems

A feasible auto-tuning method for DC brushless servo systems that introduces fuzzy algorithms is described. This is basically considered as a technique to adjust two gains of a proportional-integral (PI) compensator under the principle of providing an additional reference generator, observer, and fuzzy inferencer with a general-purpose speed control loop including PI regulator. It is possible to adjust the gains so as to be an optimum level through repeating 10 responses or more step responses in relation to variations of load inertia and mechanical vibration in addition to control characteristic fluctuations. It is proved that a DC brushless servo system can be automatically tuned to provide an optimum response if it is in a completely unstable state on the basis of the experimental results