Using Convolutional Neural Networks for Relative Pose Estimation of a Non-Cooperative Spacecraft with Thermal Infrared Imagery
This addresses the perception challenges for chaser spacecraft in on-orbit servicing and Active Debris Removal missions, offering a solution for low-light conditions, though it is incremental as it adapts existing CNN methods to thermal imagery.
The paper tackles the problem of estimating the relative pose of a non-cooperative spacecraft using thermal infrared imagery, proposing Convolutional Neural Networks trained on visible images to provide coarse pose estimation, with robustness demonstrated on synthetic data and in a laboratory environment.
Recent interest in on-orbit servicing and Active Debris Removal (ADR) missions have driven the need for technologies to enable non-cooperative rendezvous manoeuvres. Such manoeuvres put heavy burden on the perception capabilities of a chaser spacecraft. This paper demonstrates Convolutional Neural Networks (CNNs) capable of providing an initial coarse pose estimation of a target from a passive thermal infrared camera feed. Thermal cameras offer a promising alternative to visible cameras, which struggle in low light conditions and are susceptible to overexposure. Often, thermal information on the target is not available a priori; this paper therefore proposes using visible images to train networks. The robustness of the models is demonstrated on two different targets, first on synthetic data, and then in a laboratory environment for a realistic scenario that might be faced during an ADR mission. Given that there is much concern over the use of CNN in critical applications due to their black box nature, we use innovative techniques to explain what is important to our network and fault conditions.