Dynamic Behaviour and Stability Analysis of Multibody Haptic Systems

To investigate the effects of mechanical design parameters on the performance of force feedback haptic devices, a representative dynamic model of the system is required. In this paper, the experimental investigations conducted on a 2DoF haptic device revealed that flexibility associated with the joints reduced the stable domain of operation considerably. Therefore, dynamic model of the investigated mechanism including the joint flexibility and physical damping is considered. The stability boundaries achieved by using the proposed flexible joint model is in good agreement with experimental results. A simplified model of the system is then developed employing a decomposition proposed in [1]. It is shown that the stability limits obtained by this simplified model give a slightly conservative but close estimate to the stability boundaries of the higher DoF flexible joint model. Such a simplified and experimentally validated model can be used for impedance-type haptic devices. The developed model makes it possible to investigate the effect of different mechanical parameters on the performance of multibody haptic systems.