Stream-Function Based 3D Obstacle Avoidance Mechanism for Mobile AUVs in the Internet of Underwater Things

Abstract

The mobility manager in the Internet of Underwater Things (IoUT) plays a major role in data acquisition. In this paper, one novel obstacle avoidance method based on fluid mechanics is discussed for autonomous underwater vehicle (AUV) in 3D IoUT. The proposed method utilizes ocean current characteristics simplified as stream-function to design an optimal 3D trajectory with an obstacle avoidance function. 3D stream-function is constructed for spherical and cylindrical obstructions in details. Theoretical analysis of 3D stream-function proves that traditional 2D stream-function can be extended to 3D IoUT space under specific conditions. One path deformation method based on virtual obstacle methodology is proposed to overcome the inherent hysteresis problem of the traditional stream-function based obstacle avoidance design. Moreover, we introduce an energy consumption model for AUV to prove that our obstacle avoidance algorithm can improve energy efficiency if actual ocean currents exist. Extensive simulation results verify that the proposed obstacle avoidance method has the characteristics of curve continuity and smoothness, enhanced obstacle avoidance effects, and high energy efficiency. Therefore, the proposed method meets the actual requirements of multi-obstacle avoidance path planning for AUV in IoUT.

Unlocking the Ocean 6G: A Review of Path-Planning Techniques for Maritime Data Harvesting Assisted by Autonomous Marine Vehicles

“…To facilitate obstacle avoidance for AUVs in data acquisition, a path-planning technique based on fluid mechanics is proposed by the work in [105], where the ocean current characteristics were simplified as a stream function to design the artificial potential field. Furthermore, the APF was extended to the application of AUV flocks by the authors of [51].…”

Binocular-Vision-Based Obstacle Avoidance Design and Experiments Verification for Underwater Quadrocopter Vehicle

“…The essence of modeling the underwater quadrocopter vehicle is to apply Newton's second law and Euler's formula to analyze the stress force. Therefore, the completed dynamic model of the proposed UQV is expressed as [25],…”

“…Moreover, an underwater obstacle avoidance mechanism is often studied in tandem with path planning [21][22][23][24][25]. Path planning for ambulatory data gathering is discussed in [21], and an autonomous underwater vehicle traverses only location points in the constructed covering set with a hierarchical grid-based obstacle avoidance strategy.…”

“…A novel three-dimensional obstacle avoidance algorithm for an autonomous underwater robot with a sphere cross-section method is proposed in our previous work [24]. Moreover, we utilize ocean current characteristics simplified as a stream-function to design an optimal 3D trajectory with an obstacle avoidance function [25]. In conclusion, these obstacle-avoidance-based path planning methods consider only path design based on prior-known obstacles but ignore how to obtain the obstacle's shape and the distance from the underwater robots.…”

Forward-Looking Sonar-Based Stream Function Algorithm for Obstacle Avoidance in Autonomous Underwater Vehicles

“…Furthermore, Nan et al [12] embarked on a rigorous exploration of the path identification algorithm in conjunction with the stream function. W. Cai and et al [13] propose a fluid mechanics-based obstacle avoidance method for AUVs in 3D IoUT, enhancing energy efficiency and multi-obstacle avoidance through path deformation and energy models. P. Yao et al [14] propose an improved IIFDS-based submerged path-planning method for autonomous underwater vehicles in intricate ocean settings.…”