Control of dead-zone process using online parameter-adaptive fuzzy logic control

New online parameter-adaptive fuzzy logic control is presented and applied to tracking control of a dead-zone process. To implement the adaptive fuzzy logic control, the normalized state distance from the origin (NSDO) and two functions using NSDO are defined. Using the one of these functions, the fuzzy sets are modified to logarithmic scale in accordance with a weighting coefficient. With this scheme, the sensitivity around the zero is increased. The other function is defined to avoid the windup phenomena in the PI-like fuzzy logic control. Using this control structure, tracking performance for a dead-zone process can be improved.