A Circle Grid-based Approach for Obstacle Avoidance Motion Planning of Unmanned Surface Vehicles

TL;DR

This paper introduces a Circle Grid-based method for obstacle avoidance in Unmanned Surface Vehicles, effectively handling static and dynamic obstacles while optimizing path safety and steering efficiency.

Contribution

The paper presents a novel Circle Grid Trajectory Cell approach that integrates USV dynamics for real-time obstacle avoidance, outperforming existing grid-based methods.

Findings

Successfully avoids static and dynamic obstacles

Reduces steering cost by 50% compared to related methods

Generates collision-free, smooth, and efficient paths

Abstract

Aiming at an obstacle avoidance problem with dynamic constraints for Unmanned Surface Vehicle (USV), a method based on Circle Grid Trajectory Cell (CGTC) is proposed. Firstly, the ship model and standardization rules are constructed to develop and constrain the trajectory, respectively. Secondly, by analyzing the properties of the circle grid, the circle grid tree is produced to guide the motion of the USV. Then, the kinematics and dynamics of the USV are considered through the on-line trajectory generator by designing a relational function that links the rudder angle, heading angle, and the central angle of the circle grid. Finally, obstacle avoidance is achieved by leveraging the on-line trajectory generator to choose a safe, smooth, and efficient path for the USV. The experimental results indicate that the proposed method can avoid both static and dynamic obstacles, have better performance in terms of distance cost and steering cost comparing with the related methods, and our method only takes 50% steering cost of the grid-based method; the collision avoidance path not only conforms to the USV dynamic characteristic but also provides a reference of steering command.