• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.11a
• /
• pp.54-58
• /
• 2006

There are many kinds of propellant tank for space systems, which should be designed and manufactured considering lots of conditions such as pressure of inside and outside, temperature and weight, etc. Among them, it is the one of the most important factors that the tanks could be designed to suspend and support the applied static and dynamic loads. Tank mounting, that installs and supports a tank in the structure, is a method that should be considered the rigid and tight jointing mechanism, including the manufacturing simplicity, the light weight and the economical budget. Methods and features for several propellant tank mountings are introduced in this paper with the applications for those in some foreign space program.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.43 no.11
• /
• pp.1028-1034
• /
• 2015

Solenoid valves for space launch vehicles require the strict limitations on the size, weight and current consumption comparing to industrial solenoid valves. The preliminary design of a cryogenic and high pressure solenoid valve for propellant tank pressurization which can ensure the operation of solenoid valve under such strict limitation conditions was preformed. The Copper and Constantan materials in coil design have used to prevent the excessive rise of the current at cryogenic state. The measured current of solenoid valve at cryogenic temperature satisfies a design requirement.

• ETRI Journal
• /
• v.37 no.6
• /
• pp.1220-1230
• /
• 2015

An autonomous valet parking (AVP) system is designed to locate a vacant parking space and park the vehicle in which it resides on behalf of the driver, once the driver has left the vehicle. In addition, the AVP is able to direct the vehicle to a location desired by the driver when requested. In this paper, for an AVP system, we introduce technology to recognize a parking space using image sensors. The proposed technology is mainly divided into three parts. First, spatial analysis is carried out using a height map that is based on dense motion stereo. Second, modelling of road markings is conducted using a probability map with a new salient-line feature extractor. Finally, parking space recognition is based on a Bayesian classifier. The experimental results show an execution time of up to 10 ms and a recognition rate of over 99%. Also, the performance and properties of the proposed technology were evaluated with a variety of data. Our algorithms, which are part of the proposed technology, are expected to apply to various research areas regarding autonomous vehicles, such as map generation, road marking recognition, localization, and environment recognition.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.9
• /
• pp.791-800
• /
• 2021

In this paper, the recent development trends of civil/military earth observation satellites of space-advanced countries and South Korea are investigated and the current status and the direction of prospective domestic satellite projects is described. The space-advanced countries are the United States, Russia, France, Germany, Italy, Israel, China and Japan. Based on the recent trends, the direction of prospective earth observation satellites is predicted. In general, the term of 'satellite development' usually refers to a concept of satellites, ground stations and launch vehicles consisting a satellite system, but in this paper the term focuses on the development of satellites, not the satellite system.

• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10b
• /
• pp.355-359
• /
• 1992

This paper presents a procedure to design a real time control system for a magnetic levitation system based on the state space approach by adopting a control method compensating attractive force according to load variation of maglev vehicle. Also the paper has realized a robust control algorithm for the change of self-inductance parameters and the disturbance such as the change of mass of Maglev vehicles. The theoretical results are applied to the gap control problems of an attractive-type-magnetic levitation system and the effectiveness is proved by the implementation of digital control using 16 bits microcomputer.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.425-430
• /
• 2002

An automatic transmission model using the bond graph techniques is developed for analyzing shift characteristics of vehicles. Bond graph models can be systemically manipulated to yield state space equations of standard form. Bond graph techniques are applied for modeling overall automatic transmission systems and shift models. A fuzzy controller is synthesized for the verification of a shifting model in the ${1^st} gear to the {2^nd}$ gear. Simulation results show the fitness of models by the bond graph techniques.

• Journal of Korean Society of Disaster and Security
• /
• v.6 no.1
• /
• pp.1-8
• /
• 2013

Walking is one of human functions and has been the base of the development of human civilization. Walking ability had made the first village and urban pattern of the mankind. Cities had been constructed for pedestrian's convenience and happy life. But conventional cities have been crowded by the rapid increasing vehicles and population since material civilization had developed. On the other hand, pedestrian space has been neglected urban districts. Chose this study to suggest a direction for improvement by following the direction of the city characteristics and roadside pedestrian space. 1. Investigate the relationship and the significance and problems of pedestrian space by finding survey of the literature and discussion with those that affect the behavior of the pedestrian environment around. 2. For a comfortable pedestrian space on the improvement of the pedestrian area of space (physical and psychological) and gait characteristics, service levels and basic data. 3. Chose how to extract the most appropriate of the best alternatives presented several proposals based on the above survey of the literature data and field survey.

• Food Science and Industry
• /
• v.49 no.4
• /
• pp.40-63
• /
• 2016

John Glenn, America's first man to eat anything in the near-weightless environment of Earth orbit, found the task of eating fairly easy. With improved packaging came improved food quality and menus. By the time of the Apollo Program, the quality and variety of food increased even further. Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste. Thermostabilized pouches were also introduced on Apollo. The task of eating in space got a big boost in Skylab. It also had a food freezer and refrigerator a convenience offered by no other vehicle before or since. Two different food systems will be used for future long-duration missions to other planets, one for traveling to and from the distant body and one for use on the surface of the moon or Mars. The transit food system will be similar to the space station food system with the exception that products with three-to five-year shelf lives will be needed. Thus, this part of the trip will be similar to what occurs aboard space missions now. The surface food system, be it lunar or planetary, will be quite different. It will be similar to a vegetarian diet that someone could cook on Earth. Once crew members arrive on the surface and establish living quarters, they can start growing crops. Once the crops are processed into edible ingredients, cooking will be done in the spacecraft's galley to make the food items. Disposal of used food packaging will be an issue since there will be no Progress vehicles to send off and incinerate into the Earth's atmosphere. Packaging materials will be used that have less mass but sufficient barrier properties for oxygen and water to maintain shelf life as those now in use.

• International Journal of Control, Automation, and Systems
• /
• v.4 no.6
• /
• pp.782-787
• /
• 2006

The role of Unmanned Aircraft Vehicles(UAVs) has been increasing significantly in both military and civilian operations. Many complex systems, such as UAVs, are difficult to model accurately because they exhibit nonlinearity and show variations with time. Therefore, the control system must address the issues of uncertainty, nonlinearity, and complexity. Hence, identification of the mathematical model is an important process in controller design. In this paper, attitude dynamics identification of UAV is investigated. Using the flight data, nonlinear state space model for attitude dynamics of UAV is derived and verified. Real time simulation results show that the model dynamics match experimental data.

• Proceedings of the IEEK Conference
• /
• 2004.06a
• /
• pp.143-146
• /
• 2004

Signals of the short wave part of centimetre, millimetre and optic wave length ranges are being broadly used in the communication, location and remote sensing systems with space channels. In this case the presence of discrete non-uniform mediums like orbital debris, space dust and other discrete formations in the propagation channel may have substantial influence upon the characteristics of wave processes. and thus upon the data system quality. Mathematical models for studying the discrete non-uniform mediums effect on the characteristics of electromagnetic wave propagation are analyzed in this paper.