A Comparison of the Effectiveness of Design Approaches for Human-Friendly Robots

Abstract

In this paper, different measures for reducing the maximum contact force during blunt collisions between a robot and a human are evaluated using simulations. An existing collision model is adapted to include a nonlinear compliant covering, articular safety mechanisms (compliant joint and two types of torque limiters), and a collision detection system. Several scenarios are simulated in which the collision occurs at a low or high velocity, the head of the person (on which the collision occurs) is constrained by a wall or free to move and the reflected motor inertia is large or small compared to the link inertia. The results show that a torque limiter in series with each actuator has the potential to significantly improve safety without reducing the robot's performances.