The problems of variable-universe fuzzy control algorithm and its convergence are studied in this paper. First, a novel potentially-inherited variable-universe fuzzy control algorithm is proposed for conventional double-input and single-output fuzzy controllers. By using a fuzzy-singleton transition function, the computation of the algorithm is significantly reduced because its operations are simplified on the variable universe of the consequent part of inference. Then, the convergence of the algorithm is proved theoretically. Finally, to confirm the algorithm's effectiveness, comparison exper...