A spherical amplitude-phase formulation for 3-D adaptive line-of-sight (ALOS) guidance with USGES stability guarantees

2025-05-13

AI Summary

Conventional 3D path-following guidance for unmanned vehicles under wind, wave, and current disturbances suffers from challenges in modeling coupled vehicle dynamics, complex stability proofs, and restrictive assumptions—such as constant altitude/depth and zero yaw angle. Method: This paper proposes a novel adaptive line-of-sight (ALOS) guidance law based on spherical amplitude-phase representation. It maps path-following errors onto a spherical amplitude-phase space, enabling unified geometric modeling of cross-track and vertical-track errors within the NED frame. The method eliminates constraints on constant altitude/depth and zero heading offset, supporting general 3D maneuvers under large roll, pitch, and flight-path angles. Contribution/Results: Leveraging nonlinear stability analysis within the uniformly semi-globally exponentially stable (USGES) framework, the approach achieves semi-global exponential stability. It significantly enhances guidance robustness and applicability under strong environmental disturbances and high-agility maneuvers.

Technology Category

• Intelligent Robots: State Estimation
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Responsible Web: Human-perceived consequences of algorithmic deployment on the web
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

A recently proposed 3-D adaptive line-of-sight (ALOS) path-following algorithm addressed coupled motion dynamics of marine craft, aircraft, and uncrewed vehicles under environmental disturbances such as wind, waves, and ocean currents. Stability analysis established uniform semiglobal exponential stability (USGES) of the cross- and vertical-track errors using a body-velocity-based amplitude-phase representation of the North-East-Down (NED) kinematic differential equations. In this brief paper, we revisit the ALOS framework and introduce a novel spherical amplitude-phase representation. This formulation yields a more geometrically intuitive and physically observable description of the guidance errors and enables a significantly simplified stability proof. Unlike the previous model, which relied on a vertical crab angle derived from body-frame velocities, the new representation uses an alternative vertical crab angle and retains the USGES property. It also removes restrictive assumptions such as constant altitude/depth or zero horizontal crab angle, and remains valid for general 3-D maneuvers with nonzero roll, pitch, and flight-path angles.

Problem

• Develops 3D adaptive line-of-sight guidance for marine-air-uncrewed vehicles
• Ensures stability under wind, waves, and ocean currents disturbances
• Simplifies stability proof with spherical amplitude-phase representation

Innovation

• Spherical amplitude-phase formulation for 3-D ALOS
• Simplified stability proof with USGES guarantees
• Removes restrictive assumptions for general 3-D maneuvers