Adaptive Switching Control Based on Dynamic Zero-Moment Point for Versatile Hip Exoskeleton Under Hybrid Locomotion

In this article, an adaptive switching controller based on the dynamic zero-moment point for versatile hip exoskeleton is proposed. The linear finite hysteretic state machine is designed to recognize hybrid motion phases. The torque planning strategy based on dynamic zero-moment point is deployed to obtain assistant torque adaptively under different locomotion. Experiments are carried out to verify the performance of the controller, confirming the stability and accuracy of the motion phase recognition, which also demonstrates excellent kinematic performance. The net metabolic rate can be reduced by 6.93% while wearing the versatile hip exoskeleton walking. The integrated surface electromyography can be reduced by 54.8% while wearing the exoskeleton lifting objects. Compared with existing research, the performance of the proposed controller has significant advantages. The proposed controller is capable of multiple types of locomotion, including flat walking, stair climbing, and lifting heavy objects with low complexity and energy consumption.