Safe controller design for circular motion of a bicycle robot using control Lyapunov function and control barrier function.

This paper investigates the safety control problem of a bicycle robot with front-wheel drive and without a trail or mechanical regulator during circular motion. Constraints on the drive angular speed necessary for the bicycle to achieve circular motion are proposed. In practical robot systems, bounded input disturbances are inevitable. To address this, we propose a safe controller that integrates the control Lyapunov function (CLF) constraints for input-to-state stability (ISS) and the control barrier function (CBF) constraints for input-to-state safety (ISSf), implemented using quadratic programming (QP). Our controller achieves enhanced safety in control while reducing control effort. The effectiveness of this controller is verified through simulation comparative experiments. Furthermore, circular motion is achieved through physical experiments with a real robot, and the effectiveness of the ISS-CLF-ISSf-CBF-QP controller is validated through comparative experiments.