Design and Analysis of a Novel Weight Reduction System for Simulating Astronauts Walking in Low-Gravity Environment

With the development of spaceflight, a strong demand for research on human activities in low-gravity or completely weightless environments in space has emerged. In this paper, a novel weight reduction system is designed to simulate astronauts walking in low-gravity environment. Based on the perfect static gravity balance, the system combines an active compensation strategy in which the wire tension mechanism drives the trunk support platform to assist people through wire-driven double parallelogram linkage. Passive balance is used to compensate partial weight of the body, and active control is used to achieve dynamic balance during the motion. In addition, static and dynamic balance control is used to evaluate the static and dynamic performance of the weight reduction system. The simulation results show that the system can significantly reduce the lower limb joint moments and ground reaction forces of the subjects, which verifies the feasibility of the system to simulate a low-gravity environment.