Modular Safety Control for Mobile Robots Using Barrier Certificates and Modified Feedback

Abstract

A modular control design is proposed for nonholonomic mobile robots where the trajectory tracking algorithm is equipped with dynamic contouring and obstacle avoidance. Barrier certificates are used to update the robot's angular velocity to avoid obstacles scattered in the operational environment. The safe range of the heading angle is calculated by enforcing an exponential decay rate on the barrier certificate. The proposed obstacle avoidance technique is compatible with a variety of trajectory tracking algorithms. Also, the dynamic contouring algorithm and feedback modification allow precision trajectory tracking using linear control components. The proposed control structure is numerically efficient, easy to tune, and independent of the number and location of obstacles. Thus, control scalability is dramatically improved, which facilitates control implementation and calibration. The numerical simulations verify the effectiveness of the proposed safety control.