Deriving a Closed-Form Solution for Over-Actuated Surface Vessels with Actuator Constraints

<p>Over-actuated surface vessels require control–allocation strategies that compute commands based on a surge–sway–yaw force vector among multiple independently steerable thrusters without violating actuator constraints. Conventional methods either solve a constrained optimization at every control step—incurring variable computational load—or apply pseudo-inverse heuristics that risk constraint violations. This thesis derives a closedform, limit-aware solution for a Unmanned Surface Vessel with two independent, steerable thrusters that achieves optimal accuracy with constant-time complexity. The proposed framework recasts allocation as an analytic inverse-kinematics problem. The attainable force workspace is partitioned into sixteen mutually exclusive operating classes, each defined by saturating two actuator variables (thrust or angle) at their nearest limits. Within each class, concise algebraic expressions yield the remaining control commands, and a scalar factor rescales end-point solutions to any interior point. A deterministic decision tree, synthesized from twenty-six boundary inequalities, selects the unique feasible class in O(1) time while guaranteeing respect for asymmetric thrust bounds for stern mounted thrusters and reduced steering envelopes of (|φ| ≤ 90°). By unifying analytic transparency with real-time efficiency, the closed-form solution presented here establishes a robust foundation for precision station keeping, autonomous docking, and fault-tolerant maneuvering of future over-actuated surface vessels operating under stringent actuator constraints.</p>

Name thesis:degree_name

Master of Science in Unmanned and Autonomous Systems Engineering

Level thesis:degree_level

Thesis - ERAU Login Required

Discipline thesis:degree_discipline

Electrical Engineering and Computer Science

Year dc:date.available

2025

Author dc:creator

• Aggarwal, Sarthak

• Marine
• Holonomic
• Azimuth
• Controls and Control Theory
• Robotics

Repository record dc:identifier

https://commons.erau.edu/edt/918

OAI identifier oai:identifier

oai:commons.erau.edu:edt-1955