Hierarchical formation control technology for multiple autonomous underwater vehicles

The employment of multiple AUVs is to perform missions while maintaining a geometric formation designated. In this paper, communication mechanism based on blackboard is introduced to support cooperation between AUVs, messages are typed according to artificial intelligence. The hierarchical formation control algorithm is proposed, including designing level, generating level, behavioural level, evaluating level. Several formation patterns are designed according to different tasks and requirements. Orderly-Quaternion sets and control matrix are defined for the design of accurate formation geometry. Behaviours of following subgoals and avoiding obstacles enable AUVs team move forward to destination by keeping ideal pattern. Formation length rate and formation maintaining rate are utilised for AUVs team to evaluate the effect of formation. Finally, the presented approach is verified by a simulation of a swarm of AUVs moving through a constrained environment.