Abstract: In order to reduce the torsional moment of the motor in Axis-2, the drive compensation devices can be used for the joint of industrial robots. The static balance compensation range of conventional balance cylinders is limited. Since of lacking in autonomy, continuity, and dynamics, balance cylinders cannot be used for compensation when load is various. The dynamic cylinder based on series elastic actuator (SEA) devices is designed to realize the automatic response of industrial robots when load is various, to obtain continuous dynamic compensation of the inertia moment and to achieve the optimum balance. Because SEA devices have features of dynamic adjustment and energy amplification, they can be used to realize balance compensation and reduce effectively the power requirement for the joint drive motor or even replace a motor of Axis-2. Thus, a new kind of flexible balance-drive device is constructed. In this paper, theoretical and experimental analyses of the dynamic model are conducted. The experimental results prove that the devices combine the effects of balancing cylinders and motors of Axis-2, as well as increasing load capacity and flexibility.

Keywords: Industrial robot; Balance mechanism; Series elastic actuator; Distributed actuator