Safety-Critical Position Control of Robots: A Model-Free Approach

This letter deals with enforcing safety in position-controlled robotic systems. We propose a safety-critical position control framework that enables a robot to safely avoid unsafe reference input positions without compromising the overall tracking performance of the existing controller. Simulation results, as well as experimental results on a quadrupedal robot, validate the practicality of our proposed controller for position-controlled robots. Our proposed approach, which uses the well-known Control Barrier Functions (CBF) framework in a model-free fashion, can serve as a safety filter alongside any model-based or model-free controller.