Dynamic matrix control (DMC) has proven to be a powerful tool for control of industrial systems. In this paper, Transfer function [5] and state space representation [10] are used for introduce a new form of DMC transfer function, that includes the smoothing filter coefficient (alpha). Then, adaptation of method is performed for speed control of a welding robot. Finally, by comparison of results with STR and PID algorithms, good characteristics and better disturbance rejection for presented method is shown experimentally.