Abstract:For its time delay and parameter varying, the brazing temperature control is difficult in brazing operations. In order to optimize brazing temperature, the brazing temperature model must be established first. Parameter identification and optimization are effective to establish precise temperature models of brazing furnaces. In this investigation, the online parameter identification on first order delay temperature model was proposed based on recursive least squares algorithm (RLS) with variable forgetting factor. Through identifying and calculating for first order delay temperature model, the mode parameters and delay time was got. Next, PID parameters optimization for the traditional objective function was implemented based on genetic algorithm (GA). The overshoot, static error index and rising time in the third stage of the heating requirements, as a result, can be well controlled under the help of modified objective function.