Design and Analysis of Power Assist Elbow for EVA Spacesuit

Abstract

Based on pneumatic artificial muscle actuator (PMA) technology, a power assist device for the elbow joint actuated by a pair of antagonist muscles was designed. Dynamic models of the power assist device were established, driving characteristics of the device were simulated. The results show that the PMA complies with the requirements of the device, and the device can compensate the resistance caused by the spacesuit and the inertia forces by motion. Hence the device will be a great help for astronauts EVA operation. The research is used as a foundation for future development of power assist spacesuit.

Jiles-Atherton-Based Hysteresis Identification of Joint Resistant Torque in Active Spacesuit Using SA-PSO Algorithm

“…Step 2. Randomly generate the initial position P i and initial velocity V i of the ith particle according to equations ( 5) and (6).…”

“…However, due to the pressure protection, the multilayer EVA spacesuit would produce an obvious resistance torque, which increases energy expenditure, limits joint mobility, and reduces ergonomic performance [3]; some simple daily operations would not be easily completed after wearing the spacesuit. In order to eliminate the influence of joint resistant torque, some structure schemes have been proposed for spacesuits, such as the MCP (mechanical counter pressure) spacesuit [4,5], the power assist elbow [6], the X1 exoskeleton [7], the elbow-assisted exoskeleton [8], and the hard thigh-hip joint [9]. On the basis of those schemes, we have proposed the concept of active spacesuit [10], that is to say, a joint-assisted exoskeleton is directly worn outside spacesuits to enhance the operational capability, as well as assist astronauts to complete various maneuvering missions.…”

Adaptive Neural Network Control with Fuzzy Compensation for Upper Limb Exoskeleton in Active Spacesuit

“…Hard thigh-hip joints [9], which are formed using a series of spherical crown shells with a certain inclined plane, have a complicated structural design and require higher precision and reliability of the rotary bearings. The power assist elbow [10] requires an inflatable bladder with an adjustable valve, which easily leaks air during movement. The X1 robotic exoskeleton [11], as a lower extremity device, can meet the needs of astronauts in orbit countermeasures, such as training the lower-limb muscles and preventing bone density loss and muscle atrophy.…”