A Pendulum Apparatus to Evaluate Unconstrained Human-Robot Contact

Abstract:
Human-robot collaboration in a shared workspace requires power and force limiting by design or control to mitigate the risk of injury to the operator. The standards literature for robot safety specifies safety requirements on robots and systems and provides guidance on risk assessment and risk reduction. Incidental contact situations between human and robot can be classified as constrained or unconstrained/free in configuration as well as transient or quasi-static in duration. This paper presents an apparatus to investigate the behavior of the robot in unconstrained transient contact situations. The goal is to develop and validate calculation methods for quantities of interest for risk assessment and risk reduction from easily measured signals. A pendulum with variable mass was chosen to represent body parts being impacted by the robot. The energy transfer can be derived from the pendulum deflection. Beside the electromechanical details of the apparatus this paper also presents methods of data recording and sample results.