ANYpulator: Design and control of a safe robotic arm

Abstract

The present paper introduces a manipulator that is developed to combine safe and dynamic interaction tasks. The system is built from lightweight carbon fiber links and novel high-performance series elastic actuator units that provide dynamic movement capability, low-impedance joint torque control, and inherent interaction safety. This enabled the implementation of a model-based direct force control method purely based on joint torque regulation. Using unified force and motion control, the end-effector position can be accurately and dynamically tracked in task space while acting safely upon (unexpected) contacts with the environment. The force control component is implemented in a novel way that shows reduced forces in comparison to existing methods when navigating across a surface of unpredictable orientation and friction. ANYpulator is tested using a haptic feedback method that renders the system dynamics and contact forces back to the user.