Using double loop DC motor drive system (DLM) of the RoboCup middle size robots as research subject, the model of
DLM has been reduced to a simple state space one by the "quasi-equivalent" modeling method, based on the
characteristic analysis of the system. Further, the parameters of the model can be exactly identified applying the
improved genetic algorithm. The results of compared experiment proved that using this model and identification ways
can get a reasonably structural and high parameters precision model. The model can describe the DLM to design the
control system for robot soccer.