Journal of Shanghai Jiao Tong University ›› 2026, Vol. 60 ›› Issue (3): 427-439.doi: 10.16183/j.cnki.jsjtu.2024.250

• Naval Architecture, Ocean and Civil Engineering • Previous Articles     Next Articles

Thrust Allocation Method for Dual Waterjet Propelled Unmanned Surface Vehicles Based on Hierarchical Optimization

LU Zhan1,2, WANG Jian1,2(), MA Qingyan3, XU Changjian3, LIANG Xiaofeng1,2   

  1. 1 Key Laboratory of Marine Intelligent Equipment and System of the Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
    2 School of Ocean and Civil Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
    3 Marine Design and Research Institute of China, Shanghai 200011, China
  • Received:2024-06-28 Revised:2024-10-11 Accepted:2024-11-25 Online:2026-03-28 Published:2026-03-30

Abstract:

Thrust allocation serves as a critical means for achieving vector propulsion in unmanned surface vessels (USV) equipped with dual waterjet thrusters. However, existing thrust allocation methods employed in vessels featuring azimuth thrusters fail to address the resolution of vector forces for dual waterjet propulsion, due to characteristics such as thrust angle limitations and reverse thrust. To achieve vector motion control of a dual waterjet propelled USV, a hierarchical optimization-based thrust allocation algorithm is proposed. In the first tier, a vector synthesis approach incorporating enhanced angle constraints is utilized to acquire top-tier vector thrust satisfying constraints on the rotating range and rate characteristics of the thrusters. In the second tier, leveraging the top-tier vector thrust values as inputs and considering constraints on thruster power and power change frequency, an optimization method based on seeking minimal distance is proposed. This method facilitates the allocation of reverse thrust angles and nozzle flow velocities for waterjet thrusters, thereby resolving singular issues in dual waterjet thrust allocation. Simulation experiments and the semi-physical simulation experiments validate the effectiveness of the hierarchical optimization-based thrust allocation algorithm for dual waterjet thrusters. The results indicate that this method enables efficient thrust allocation for dual waterjet thrusters, while concurrently limiting fluctuations in thruster power frequency and amplitude during expected thrust variations, thereby reducing shafting wear while achieving target vector thrust.

Key words: unmanned surface vessels (USV), dual waterjet propulsion, hierarchical optimization, thrust allocation

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