Considerations on the Dynamics of Biofidelic Sensors in the Assessment of Human-Robot Impacts

Ensuring the safety of physical human-robot interaction (pHRI) is of utmost importance for industries and organisations seeking to incorporate robots into their workspaces. To address this concern, the ISO/TS 15066:2016 outlines hazard analysis and preventive measures for ensuring safety in Human-Robot Collaboration (HRC). To analyse human-robot contact, it is common practice to separately evaluate the "transient" and "quasi-static" contact phases. Accurately measuring transient forces during close human-robot collaboration requires so-called "biofidelic" sensors that closely mimic human tissue properties, featuring adequate bandwidth and balanced damping. The dynamics of physical human-robot interactions using biofidelic measuring devices are being explored in this research. In this paper, one biofidelic sensor is tested to analyse its dynamic characteristics and identify the main factors influencing its performance and its practical applications for testing. To this aim, sensor parameters, such as natural frequency and damping coefficient, are estimated by utilising a custom physical pendulum setup to impact the sensor. Mathematical models developed to characterise the sensor system and pendulum dynamics are also disclosed.