Estimation of Evaluation Function for Generating Upper Limb Posture during Task Execution

Generating the upper limb posture of a human arm is important when executing tasks involving position and force control. In this article, we derive the evaluation function to generate the upper limb posture of a human arm when connecting an RCA plug. We measure the upper limb posture of one subject, while connecting the plug, to determine factors in the evaluation function and of eight more subjects on different positional plugs, to estimate the factor values. Based from the experimental results, the evaluation function can be expressed as a weighted linear sum of nine factors such as power transmissibility of joints, torque, and manipulability measure of joints. It was shown that the generated upper limb posture is close enough to the measured posture. The most important constituent factors of the evaluation function are found to be manipulability measure of both elbow and wrist, and the wrist torque.