Decoupling is a difficult practical problem in controller design.In order to eliminate the coupling of systems,a decoupler is designed for a practical system model by building the transfer function of the model and utilizing the principle of static decoupling in multi-variable frequency design theory.This method eliminates the coupling elements of the system and turns the system into two SISO models.Then,a decoupling PID controller is designed.Simulation results show that the decoupler is effective.The algo...