Path planning technologies for USV formation based on improved RRT

  Objectives  An algorithm for unmanned surface vehicle(USV)formation path planning based on an improved RRT algorithm is proposed for global path planning and obstacle avoidance.

  Methods  For the shape stability of a USV formation, 'non-strict conformal correction vector' and 'non-strict conformal control circular area' are presented in the EXTEND operation in RRT, making the extension direction of the search tree tend towards the strict conformal point. For the situation of sudden obstacle collision with non-strict conformal planning points, adjustable collision avoidance circle and 'obstacle correction vector' are presented in the collision-check operation in RRT, making the USV formation safely avoid collision and maintain stable formation to the greatest extent.

  Results  The results show that a USV formation displays good conformal performance under the action of this algorithm, and effectively avoids sudden obstacles.

  Conclusions  This research shows that the improved algorithm has such advantages as high efficiency, good stabilization and high-quality planning paths, making it of great significance for practical engineering application.