Suppression of limit cycle oscillation for two-mass system with backlash nonlinearity based on dual luenberger observer

This paper mainly focuses on the characteristics of limit cycle oscillation due to backlash nonlinearity and its suppression method in a two-mass drive system. The full-closed loop control system is proposed to improve positioning accuracy. However, the performance is poor due to the transmission backlash. Therefore it is of great significance to analyze the characteristics of limit cycle. In the paper the two-mass drive system with backlash is modeled and results of the characteristics are given firstly. Then a control strategy with dual Luenberger observer is introduced to suppress the oscillation. With the difference of observed shaft torque and observed load torque, the electromagnetic torque is compensated. Finally the correctness of the control strategy is proved by simulation experiments under different control stiffness and deadband. A tradeoff between stability and responsiveness of the system is achieved.