Safety Evaluation of Human Arm Operations Using IMU Sensors with a Spring-Damper-Mass Predictive Model
Musab Zubair Inamdar, Seyed Amir Tafrishi
TL;DR
The paper tackles real-time safety monitoring in human–robot collaboration during wrist movements by extending a Predictive Safety Model to wrist motion using a wrist-mounted IMU and a spring-damper-mass framework. Safety is quantified with an impedance-based error combining angular position and velocity deviations, plus a probabilistic safety map and frequency-domain analysis in a defined range to identify unsafe signatures. Key contributions include adapting the PSM to the wrist, developing a probabilistic motion distribution, introducing dual-priority safety criteria, and validating on tool fastening, visual inspection, and pick-and-place tasks with robust real-time performance. The approach offers computational efficiency suitable for real-time deployment and lays groundwork for adaptive risk assessment in Industry 4.0/5.0 human–robot collaboration.
Abstract
This paper presents a novel approach to real-time safety monitoring in human-robot collaborative manufacturing environments through a wrist-mounted Inertial Measurement Unit (IMU) system integrated with a Predictive Safety Model (PSM). The proposed system extends previous PSM implementations through the adaptation of a spring-damper-mass model specifically optimized for wrist motions, employing probabilistic safety assessment through impedance-based computations. We analyze our proposed impedance-based safety approach with frequency domain methods, establishing quantitative safety thresholds through comprehensive comparative analysis. Experimental validation across three manufacturing tasks - tool manipulation, visual inspection, and pick-and-place operations. Results show robust performance across diverse manufacturing scenarios while maintaining computational efficiency through optimized parameter selection. This work establishes a foundation for future developments in adaptive risk assessment in real-time for human-robot collaborative manufacturing environments.
