# Geometric line-of-sight guidance law with exponential switching sliding mode control for marine vehicles’ path following

## TL;DR

This paper introduces a new guidance and control method for marine vehicles to follow paths more accurately and adaptively in complex environments.

## Contribution

A novel geometric line-of-sight guidance law and an improved exponential switching sliding mode control method are proposed.

## Key findings

- The guidance law adapts to various paths by adjusting to cross-track errors and curvature.
- The control method achieves rapid convergence and reduces chatter while rejecting disturbances.
- Numerical simulations confirm the methods' effectiveness, robustness, and adaptability.

## Abstract

Marine vehicle guidance and control technology serves as the core support for advancing marine development and enabling scientific exploration. Its accuracy, autonomy, and environmental adaptability directly determine a vehicle’s mission effectiveness in complex marine environments. This paper explores path following for marine vehicles in the horizontal plane. To tackle the limitation of a fixed look-ahead distance, we develop a novel geometric line-of-sight guidance law. It adapts to diverse compound paths by dynamically adjusting according to cross-track errors and local path curvature. Then, to enhance control performance, we present an improved exponential switching law for sliding mode control, enabling rapid convergence, disturbance rejection, and chatter reduction. Additionally, integral sliding mode control is integrated to stabilize yaw angular velocity, ensuring the system’s global asymptotic stability. Through a series of numerical simulations, the effectiveness, robustness, and adaptability of our proposed methods are verified.