Safety is a fundamental issue in autonomous mobile robot design. This paper presents a safety-critical control framework for nonholonomic tractor-trailer vehicles subject to both safety and physical constraints. Control barrier functions (CBFs) are employed to enforce hard safety constraints, generating a safe set that ensures obstacle avoidance. These CBFs are integrated with control Lyapunov functions (CLFs) to enable trajectory tracking while maintaining safety. To reduce conflicts between CBFs and CLFs and improve obstacle avoidance performance, we optimize their decay rates. Leveraging the concept of differential flatness, we design a controller that enables the system to follow the desired safe trajectory. Finally, the effectiveness and performance of the proposed method are demonstrated through numerical simulations and real-world experiments.
Yu et al. (Sat,) studied this question.