KMITL Expo 2026 LogoKMITL 66th Anniversary Logo

Vision-Based Spacecraft Pose Estimation

Vision-Based Spacecraft Pose Estimation

Abstract

The capture of a target spacecraft by a chaser is an on-orbit docking operation that requires an accurate, reliable, and robust object recognition algorithm. Vision-based guided spacecraft relative motion during close-proximity maneuvers has been consecutively applied using dynamic modeling as a spacecraft on-orbit service system. This research constructs a vision-based pose estimation model that performs image processing via a deep convolutional neural network. The pose estimation model was constructed by repurposing a modified pretrained GoogLeNet model with the available Unreal Engine 4 rendered dataset of the Soyuz spacecraft. In the implementation, the convolutional neural network learns from the data samples to create correlations between the images and the spacecraft’s six degrees-of-freedom parameters. The experiment has compared an exponential-based loss function and a weighted Euclidean-based loss function. Using the weighted Euclidean-based loss function, the implemented pose estimation model achieved moderately high performance with a position accuracy of 92.53 percent and an error of 1.2 m. The in-attitude prediction accuracy can reach 87.93 percent, and the errors in the three Euler angles do not exceed 7.6 degrees. This research can contribute to spacecraft detection and tracking problems. Although the finished vision-based model is specific to the environment of synthetic dataset, the model could be trained further to address actual docking operations in the future.

Objective

In one, docking is defined as “when one incoming spacecraft rendezvous with another spacecraft and flies a controlled collision trajectory in such a manner to align and mesh the interface mechanisms”, and defined docking as an on-orbital service to connect two free-flying man-made space objects. The service should be supported by an accurate, reliable, and robust positioning and orientation (pose) estimation system. Therefore, pose estimation is an essential process in an on-orbit spacecraft docking operation. The position estimation can be obtained by the most well-known cooperative measurement, a Global Positioning System (GPS), while the spacecraft attitude can be measured by an installed Inertial Measurement Unit (IMU). However, these methods are not applicable to non-cooperative targets. Many studies and missions have been performed by focusing on mutually cooperative satellites. However, the demand for non-cooperative satellites may increase in the future. Therefore, determining the attitude of non-cooperative spacecrafts is a challenging technological research problem that can improve spacecraft docking operations. One traditional method, which is based on spacecraft control principles, is to estimate the position and attitude of a spacecraft using the equations of motion, which are a function of time. However, the prediction using a spacecraft equation of motion needs support from the sensor fusion to achieve the highest accuracy of the state estimation algorithm. For non-cooperative spacecraft, a vision-based pose estimator is currently developing for space application with a faster and more powerful computational resource.

Other Innovations

SOH  Estimation for  Li-ion battery

คณะวิศวกรรมศาสตร์

SOH Estimation for Li-ion battery

Currently, lithium batteries are widely used in electronic devices and electric vehicles, making the estimation of their State of Health (SOH) crucial. Accurate SOH estimation helps extend battery lifespan, reduce maintenance costs, and prevent safety issues such as overheating or explosions. This project aims to study and analyze mathematical models of batteries and develop SOH estimation techniques using Neural Networks to enhance accuracy and evaluation speed. The experiment involved collecting charge and discharge data from three lithium battery cells under controlled temperature conditions while maintaining a constant current. The current, voltage, and time data were recorded and analyzed to determine the battery capacity for each cycle. These data were then used to train a Neural Network model. The results demonstrated an effective method for predicting battery health status. The outcomes of this project can contribute to the development of a Battery Management System (BMS) that improves battery efficiency and longevity. Additionally, it provides a foundation for applying artificial intelligence techniques in the energy sector effectively.

Read more
Graphene Oxide Composite Membrane for Wastewater Treatment

คณะวิทยาศาสตร์

Graphene Oxide Composite Membrane for Wastewater Treatment

This research focuses on the fabrication of graphene oxide (GO) composite membranes using the Phase-Inversion Method, which transforms polymers from liquid to solid through phase separation. This process creates a porous membrane structure, making it highly adaptable, cost-effective, and suitable for wastewater treatment, separation processes, and industrial filtration applications. Graphene oxide, with its nano-layered structure, offers excellent molecular sieving properties, high water permeability, and chemical and mechanical stability, making it an ideal additive for membrane fabrication. The GO-based membrane demonstrates efficient removal of nanoparticles, heavy metal ions (Pb²⁺, Cr⁶⁺, Hg²⁺), organic pollutants, and microorganisms while exhibiting antifouling properties and high hydrophilicity due to oxygen-functional groups. Applications of this membrane include industrial wastewater treatment, desalination, and the removal of pharmaceutical contaminants, such as antibiotics and hormones. The incorporation of GO enhances membrane performance, providing a sustainable and energy-efficient solution for water purification.

Read more
Hacking the Show: QoP and Log Data Analyses of Interactive Concert Experiences

วิทยาลัยวิศวกรรมสังคีต

Hacking the Show: QoP and Log Data Analyses of Interactive Concert Experiences

This work attempts to spark conversations about the technical and creative aspects of participatory concert settings. It features the results of two interactive research concerts on basis of audience participation quantities, motion analysis and log data clustering. Ultimately, it poses questions how participatory work can help when teaching interactive technology for the arts and beyond.

Read more