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.
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.
คณะวิทยาศาสตร์
This project aims to investigate and develop an energy storage system utilizing solar energy sources through the integration of solar cell technology and Graphene Quantum Dot Battery, representing a novel approach to enhancing energy storage efficiency and prolonging the lifespan of renewable energy systems. The selection of graphene and quantum dots as materials for battery development is attributed to their exceptional properties, including high electrical conductivity, charge storage capacity, efficient energy transfer, and enhanced stability.
คณะสถาปัตยกรรม ศิลปะและการออกแบบ
The forest firefighting suit consists of the following components and uses: The forest firefighting suit is designed and developed to be suitable for the behavior of the officers and the conditions of the work area, consisting of a shirt and pants. The material used in the sewing of the suit is aramid fabric, which has the property of being able to prevent the spread of fire, to prevent the officers from burning while performing their duties in the event that the forest fire spreads close to them, which is different from the current suits that cannot prevent fires. The shirt is designed with a mesh on the side of the body to release internal heat so that air can circulate well. The sleeves at the elbows have a support point to prevent contact with the ground or obstacles. The collar has a slot for a portable fan and a fan air circulation channel on the back, which can be turned on while performing forest firefighting duties, helping to prevent the body temperature from getting too hot, reducing the risk of heatstroke. When the fan battery runs out, it can be removed for charging and put back in when needed. The pants are designed with mesh on the inside or in blind spots to release internal heat so that air can circulate well. The pants at the knees have a support point to prevent contact with the ground or obstacles. The forest firefighting suit, consisting of a shirt and pants, has been designed and developed to be able to be produced domestically, reducing imports from abroad
คณะเทคโนโลยีการเกษตร
The innovation of the vertical aquaponics system for rearing golden apple snails integrating with vegetable cultivation by using substrates to water treatment. The system aims to maximize the use of vertical space, save water, and produce safe vegetables for consumption or commercial purposes, and to support living things. The golden apple snail excretes wastes/leftover food scraps that are filtered on the substrates used for water treatment. Meanwhile, natural bacteria help change these wastes into nutrients that plants can use. Therefore, the system is environmentally friendly.