Real-Time Thermal-Inertial Odometry on Embedded Hardware for High-Speed GPS-Denied Flight

TL;DR

This paper introduces a real-time thermal-inertial odometry system for high-speed, GPS-denied flight on embedded hardware, combining sensor fusion, feature filtering, and machine learning to enable reliable navigation during aggressive maneuvers.

Contribution

The paper presents a novel thermal-inertial odometry system that integrates multiple sensors and a learned altitude correction model, optimized for high-speed embedded UAV flight.

Findings

Supports closed-loop quadrotor flight at 30 m/s

Drift remains under 2% over kilometer-scale trajectories

Outperforms baseline models in altitude uncertainty modeling

Abstract

We present a real-time monocular thermal-inertial odometry system designed for high-velocity, GPS-denied flight on embedded hardware. The system fuses measurements from a FLIR Boson+ 640 longwave infrared camera, a high-rate IMU, a laser range finder, a barometer, and a magnetometer within a fixed-lag factor graph. To sustain reliable feature tracks under motion blur, low contrast, and rapid viewpoint changes, we employ a lightweight thermal-optimized front-end with multi-stage feature filtering. Laser range finder measurements provide per-feature depth priors that stabilize scale during weakly observable motion. High-rate inertial data is first pre-filtered using a Chebyshev Type II infinite impulse response (IIR) filter and then preintegrated, improving robustness to airframe vibrations during aggressive maneuvers. To address barometric altitude errors induced at high airspeeds, we train an uncertainty-aware gated recurrent unit (GRU) network that models the temporal dynamics of static pressure distortion, outperforming polynomial and multi-layer perceptron (MLP) baselines. Integrated on an NVIDIA Jetson Xavier NX, the complete system supports closed-loop quadrotor flight at 30 m/s with drift under 2% over kilometer-scale trajectories. These contributions expand the operational envelope of thermal-inertial navigation, enabling reliable high-speed flight in visually degraded and GPS-denied environments.