Extravehicular Operating Load Analysis Using Inverse Kinematic Astronaut Modeling Method
A fine-grained analysis is conducted on the loads caused by the constraints on handrails and foot restraints during extravehicular activities(EVAs)of Chinese astronauts.The movement characteristics of astronauts in a weightless environment are summarized,and an inverse kinematics algorithm is used to model upper limb operations.Conditions such as motion energy consumption,relations between joint force outputting capability and joint angle,and reactive torque of the spacesuit are considered as redundant system constraints.Factors such as height,weight,and operating position of astronauts are considered to analyze the impact on the solution the magnitude of applied loads.Through the analysis of examples involving spacewalk along handrails and move heavy objects,the proposed method demonstrate feasibility in solving complex inverse kinematics problems for EVAs based on the criterion of minimum energy consumption.Based on the analysis of fine-grained parameters,the relations between the operating loads on the constraint points and astronaut mass,height or handle distance are analyzed,which could provide practicability toward a more accurate operating load analysis for spacecraft structure design.