Cooperative Control Strategy of Pump-controlled Exoskeleton Robot Walking

Abstract

Human-robot collaborative control is one of the key technologies for active exoskeleton robots to achieve assisted walking. Based on the excellent backdrivability of the pump-controlled drive unit, an exoskeleton robot walking coordinated control strategy with active assistance in the standing phase and passive follow-up in the swing phase is proposed. The standing phase is the main force generation process of human walking. This paper establishes the kinematics and dynamics model of pump-controlled joints and obtains the dynamic relationship between the joint motion trajectory of the exoskeleton robot and the output force of the pump-controlled drive unit. Based on the human-robot interaction force information at the end of the exoskeleton robot's back, this paper realizes the active and compliant power-assisted control of the standing phase. During the swing phase, the swinging leg of the human body has the characteristics of small force and fast speed. This paper makes full use of the backdrivability of the pump-controlled drive unit to realize the passive follow-up of the swing phase. The actual test results based on the pump-controlled exoskeleton robot show that the proposed walking cooperative control strategy is effective and feasible, which reduces the difficulty of human-robot collaborative control and the energy consumption of assisted walking.