Suppression of mechanical resonance using torque disturbance observer for two-inertia system with backlash

In servo system, elastic component in transmission can produce mechanical resonance. The existence of backlash will aggravate the damage of resonance. According to dead-zone model, two-mass elastic system with backlash is established. The conclusion that the existence of backlash decreases the elastic coefficient of shaft equivalently and its quantitative relation are researched. This paper proposes a torque disturbance observer to realize the suppression of mechanical resonance with limiting control for shaft torque amplitude. The observer can decrease ratio of inertia equivalently in the case of no identification of backlash value. It has a compensation result that system is changed to a rigid system with single moment of inertia. In addition, this compensation algorithm is independent with parameters and configuration of speed controller. Simulations and experiments demonstrate the effectiveness of this torque disturbance observer.