New PID parameters tuning method based on modified ant colony algorithm

PID parameters are the important parameters to influence the control performance. There are some defects of low ability of full search, easy to get stagnate in PID parameters tuning strategy based on Basic Ant Colony Algorithm. In order to solve this problem, a new kind of PID parameters tuning strategy based on Max-Min Ant System named MPID is proposed in this paper. On the basis of introducing the principle of MPID Algorithm, this paper elaborates PID parameters expressing method, state transition probability formula, objective function, and the detailed realizing process of the new algorithm is also presented. By testing two different control systems,such as high order and time delays, MPID Algorithm is demonstrated to be better than Z-N Algorithm , Basic Ant Colony Algorithm and other modified Ant Colony Algorithm in control performance, and the overshoot σ of step response to the system and the adjusted time t_s are improved.