An improved artificial potential field (IAPF) algorithm is proposed in this paper to promote the path planning characteristics of autonomous underwater vehicle (AUV). There are two critical problems restricting the application of obstacle avoidance path planning for the artificial potential field (APF) algorithm, one is the local minima and the other is the target unreachability problem. Therefore, the distance between the target and the AUV in attractive field is introduced into the repulsive potential field to modify the repulsive force so as to solve the problem of target unreachability. Moreover, an additional force is added to the resultant force to break the equilibrium when the local minima situation occurs. Ultimately, the simulation experiment validates that the improved artificial potential field method is an efficient way to realize the path planning for AUV in 3D space.

Abstract This paper presents a whale optimization algorithm (WOA) based on forward looking sonar to achieve two‐dimensional optimal path planning for an autonomous underwater vehicle. The purpose of path planning is not only to effectively avoid threat regions and safely reach the intended target with minimum fuel cost but also to obtain an optimal or near‐optimal path in a complex ocean battlefield environment. The WOA, based on the bubble‐net attacking behavior of humpback whales, mimics encircling the prey, attacks with a bubble‐net method, and search for prey to effectively determine the global optimal solution in the search space. The WOA not only has fast convergence speed and high calculation accuracy but can also effectively balance exploration and exploitation to avoid falling into a local optimum and obtain the global optimal solution. Five sets of experiments are applied to verify the superiority and stability of the WOA. Compared with other algorithms, such as artificial bee colony, bat algorithm, cuckoo search, flower pollination algorithm, moth‐flame optimization algorithm, particle swarm optimization, and water wave optimization, the WOA exhibits better optimization performance and stronger robustness. The experimental results reveal that the WOA can find the shortest path compared with all the other algorithms, and it is an effective and feasible method for solving the path planning problem.

The multiple UUVs(unmanned underwater vehicles) can maintain a certain formation and complete the designated route cruise mission by using the path tracking controller. According to the problem of multiple UUV path tracking under discrete information conditions, a path tracking controller based on virtual leader is proposed in this paper considering communication delays. Firstly, the coupled nonlinear UUV kinematics and dynamics equations are transformed into second-order affine forms by using feedback linearization method, and the mathematical model under discrete time is given. Secondly, the path tracking controller is designed in the case of bounded time delays, and the sufficient conditions are analyzed and proposed based on the matrix theory. Finally, the effectiveness of the proposed algorithm is proved by the simulation experiments, all trajectories of each UUV converge to the desired trajectories under the specific formation.