Visual Tracking with Intermittent Visibility: Switched Control Design and Implementation

TL;DR

This paper introduces a switched control visual tracking system for drones that maintains target proximity and visibility despite intermittent visual contact, improving robustness and tracking accuracy.

Contribution

The paper presents a novel Switched Visual Tracker (SVT) with stability guarantees, combining tracking and recovery modes for better handling of vision loss in autonomous drones.

Findings

Reduces average tracking error by up to 45%

Significantly improves visibility duration

Demonstrates effectiveness on drone target tracking

Abstract

This paper addresses the problem of visual target tracking in scenarios where a pursuer may experience intermittent loss of visibility of the target. The design of a Switched Visual Tracker (SVT) is presented which aims to meet the competing requirements of maintaining both proximity and visibility. SVT alternates between a visual tracking mode for following the target, and a recovery mode for regaining visual contact when the target falls out of sight. We establish the stability of SVT by extending the average dwell time theorem from switched systems theory, which may be of independent interest. Our implementation of SVT on an Agilicious drone [1] illustrates its effectiveness on tracking various target trajectories: it reduces the average tracking error by up to 45% and significantly improves visibility duration compared to a baseline algorithm. The results show that our approach effectively handles intermittent vision loss, offering enhanced robustness and adaptability for real-world autonomous missions. Additionally, we demonstrate how the stability analysis provides valuable guidance for selecting parameters, such as tracking speed and recovery distance, to optimize the SVT's performance.