An Opticalmechanics Framework for Dynamic Estimation of Multibody Systems
2026-06-08 • Computer Vision and Pattern Recognition
Computer Vision and Pattern Recognition
AI summaryⓘ
The authors created a new way to understand how parts of the human body move without touching it or using special sensors. They used cameras to measure movement and combined that with a computer model to guess the forces in joints like the wrist. By comparing their guesses to actual measurements, they showed their method works well with small errors. This approach could help study movement in places where using physical sensors isn't possible.
multibody dynamicskinematicsjoint torquegenetic algorithmimage-based measurementnon-contact sensingair-bearing platformdynamic estimationoptimization
Authors
Banglei Guan, Xuanyu Bai, Qingquan Chen, Zibin Liu, Dongcai Tan, Zhenbao Yu, Yang Shang, Qifeng Yu
Abstract
Conventional dynamics analysis of the human body is often constrained by the need for contact force and torque sensors and controlled laboratory environments. To address this issue, this study proposes an opticalmechanics kinematic-dynamic integrated estimation framework for multibody systems. Specifically, a constrained multibody model is established to describe the system dynamics, while image-measured kinematic quantities are used as non contact inputs for dynamic estimation. The unknown joint torque is then identified through a genetic-algorithm based optimization by minimizing the discrepancy between model-predicted and image-measured kinematic quan tities. Experimental validation on an air-bearing platform showed that the wrist joint torque estimated from image data achieved a mean absolute error of 0.46 Nm compared with sensor measurements. In the forward prediction test, the model-predicted angular velocity achieved a mean absolute error of 0.006 rad/s relative to the image-measured results. This study demonstrates the potential of combining image measurement and mechanical modeling for non-contact dynamic estimation in scenarios where direct force and torque measurement is difficult.