3 research outputs found
Deep Learning for Spacecraft Pose Estimation from Photorealistic Rendering
On-orbit proximity operations in space rendezvous, docking and debris removal
require precise and robust 6D pose estimation under a wide range of lighting
conditions and against highly textured background, i.e., the Earth. This paper
investigates leveraging deep learning and photorealistic rendering for
monocular pose estimation of known uncooperative spacecrafts. We first present
a simulator built on Unreal Engine 4, named URSO, to generate labeled images of
spacecrafts orbiting the Earth, which can be used to train and evaluate neural
networks. Secondly, we propose a deep learning framework for pose estimation
based on orientation soft classification, which allows modelling orientation
ambiguity as a mixture of Gaussians. This framework was evaluated both on URSO
datasets and the ESA pose estimation challenge. In this competition, our best
model achieved 3rd place on the synthetic test set and 2nd place on the real
test set. Moreover, our results show the impact of several architectural and
training aspects, and we demonstrate qualitatively how models learned on URSO
datasets can perform on real images from space.Comment: * Adding more related work and reference
Robust On-Manifold Optimization for Uncooperative Space Relative Navigation with a Single Camera
Optical cameras are gaining popularity as the suitable sensor for relative navigation in space due to their attractive sizing, power, and cost properties when compared with conventional flight hardware or costly laser-based systems. However, a camera cannot infer depth information on its own, which is often solved by introducing complementary sensors or a second camera. In this paper, an innovative model-based approach is demonstrated to estimate the six-dimensional pose of a target relative to the chaser spacecraft using solely a monocular setup. The observed facet of the target is tackled as a classification problem, where the three-dimensional shape is learned offline using Gaussian mixture modeling. The estimate is refined by minimizing two different robust loss functions based on local feature correspondences. The resulting pseudomeasurements are processed and fused with an extended Kalman filter. The entire optimization framework is designed to operate directly on the SE(3) manifold, uncoupling the process and measurement models from the global attitude state representation. It is validated on realistic synthetic and laboratory datasets of a rendezvous trajectory with the complex spacecraft Envisat, demonstrating estimation of the relative pose with high accuracy over full tumbling motion. Further evaluation is performed on the open-source SPEED dataset