Kinematics Modeling and Simulation Analysis of Human Upper Limbs for Rod Lifting

With the development of technology, exoskeleton robots have wide application in industrialization and civilian. The purpose of this paper is to analyze the kinematics and kinetics during rod lifting, thus providing the necessary suggestion for power grid maintenance exoskeleton design. Firstly, the human motion data was collected through the 3D motion capture system. Secondly, this article proposed an improved four degrees of freedom model for human pole lifting based on DH (Denavit-Hartenberg) method and human anatomy. Thirdly, we conducted dynamic analysis on the pole lifting motion based on the model and in Opensim software. During the pole hanging stage, the maximum torque of the shoulder joint was 27.7N, and the maximum torque of the elbow joint was 28.3N based on the model, with error rates(the ratio of the error between the calculated value and the simulated value to the calculated value) of 11.5% and 2.8% referring to the data in Opensim simulation. During the pole hanging stage, the maximum torque of the shoulder joint was 36.2N, and the maximum torque of the elbow joint was 16.3N, with error rates of 7.5% and 6.7%. Due to the fact that the source of joint torque is muscle force, we further analyzed muscle strength. The results indicated that we can assist with BRA (brachialis) and INFSP (infraspinatus) during the pole lifting stage, and BIClong (biceps brachii, long head) and INFSP (infraspinatus) during the pole hanging phase. This study provides a theoretical basis for the design of structure and control strategy of upper limb exoskeleton.