Research on a novel control strategy combined with fuzzy and Smith pre-estimator for a kind of system with time-delay

In consideration of capacity of Smith pre-estimator to solve oscillation problem and features of fuzzy controller with good dynamic performance and strong robustness, the novel combined controller with fuzzy controller and Smith pre-estimator was constituted to solve control of object with pure time-delay and large inertia. The design procedure of fuzzy controller consists of fuzziness of input quantities, synthesis algorithm of input quantities, rules reasoning, output judgement and inverse fuzziness. After introducing Smith compensation, the equivalent transfer function of controlled object will not contain term of time-delay, it means the effect of time-delay is removed. The calculating method for output of Smith estimator was given.The result of simulation has shown that Smith pre-estimator may remove oscillation phenomena in response.