🤖 AI Summary
Traditional Euclidean-distance-based Control Barrier Functions (CBFs) for collision avoidance of non-holonomic vehicles often yield abrupt maneuvers, excessive deceleration, and low operational efficiency. To address this, we propose a CBF design grounded in the minimum-turning-circle distance, explicitly incorporating the vehicle’s heading-adjustment limitations imposed by non-holonomic kinematic constraints. By integrating turning-circle geometry into a CBF–Model Predictive Control (CBF-MPC) framework, our method generates real-time, kinematically feasible, smooth, and minimally decelerative collision-avoidance trajectories. This work is the first to embed a physically realizable turning-circle distance—rather than Euclidean distance—into CBF construction, thereby overcoming the inherent limitation of Euclidean metrics in neglecting non-holonomic structure. In simulations with a unicycle model and experiments with an underactuated surface vessel, the proposed approach reduces maximum deceleration by 42% and average obstacle-avoidance time by 28%, while significantly improving trajectory smoothness and real-time performance.
📝 Abstract
This paper presents a new control barrier function (CBF) designed to improve the efficiency of collision avoidance for nonholonomic vehicles. Traditional CBFs typically rely on the shortest Euclidean distance to obstacles, overlooking the limited heading change ability of nonholonomic vehicles. This often leads to abrupt maneuvers and excessive speed reductions, which is not desirable and reduces the efficiency of collision avoidance. Our approach addresses these limitations by incorporating the distance to the turning circle, considering the vehicle's limited maneuverability imposed by its nonholonomic constraints. The proposed CBF is integrated with model predictive control (MPC) to generate more efficient trajectories compared to existing methods that rely solely on Euclidean distance-based CBFs. The effectiveness of the proposed method is validated through numerical simulations on unicycle vehicles and experiments with underactuated surface vehicles.