Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158287
Serdar Ay, O. E. Vatandas, A. Hacioglu
In recent years, Stewart Platform Mechanism has been utilized extensively in applications which are vibration control and aligning optics of astronomical telescopes, satellite dish positioning, flight simulators, and so on requiring high precision, loading capacity, accuracy, rigidity and high velocity. However, the limited workspace, complex kinematic / kinetic solutions and singularities inside the workspace are the most important problems encountered with regard to this type of mechanisms. There are some parameters which affect significantly the workspace of Stewart Platform Mechanism. Some of these parameters are leg lengths, joint location angles and radius of joint location. Within this study, the effect of the radius of joint location of both moving platform and fixed platform on the workspace is investigated by calculating workspaces and comparing results for different radii of joint locations utilizing inverse kinematics technique.
{"title":"The effect of radius of joint location on workspace analysis of the 6-6 Stewart Platform Mechanism","authors":"Serdar Ay, O. E. Vatandas, A. Hacioglu","doi":"10.1109/RAST.2009.5158287","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158287","url":null,"abstract":"In recent years, Stewart Platform Mechanism has been utilized extensively in applications which are vibration control and aligning optics of astronomical telescopes, satellite dish positioning, flight simulators, and so on requiring high precision, loading capacity, accuracy, rigidity and high velocity. However, the limited workspace, complex kinematic / kinetic solutions and singularities inside the workspace are the most important problems encountered with regard to this type of mechanisms. There are some parameters which affect significantly the workspace of Stewart Platform Mechanism. Some of these parameters are leg lengths, joint location angles and radius of joint location. Within this study, the effect of the radius of joint location of both moving platform and fixed platform on the workspace is investigated by calculating workspaces and comparing results for different radii of joint locations utilizing inverse kinematics technique.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131376428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158198
Ehsan A. Tahmasebi, H. Karimi, R. Ebrahimi
Conceptual design algorithm of hybrid rocket motor with solid fuel and liquid oxidizer is investigated in this study. Hybrid chemical rocket propulsion is presently of interest due to reduced system complexity compared to classical chemical propulsion systems. A computational code for conceptual design and performance modeling of hybrid propulsion motor developed. Results are validating with experimental test results.
{"title":"Conceptual design and performancenumerical modeling of hybrid propulsion motor","authors":"Ehsan A. Tahmasebi, H. Karimi, R. Ebrahimi","doi":"10.1109/RAST.2009.5158198","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158198","url":null,"abstract":"Conceptual design algorithm of hybrid rocket motor with solid fuel and liquid oxidizer is investigated in this study. Hybrid chemical rocket propulsion is presently of interest due to reduced system complexity compared to classical chemical propulsion systems. A computational code for conceptual design and performance modeling of hybrid propulsion motor developed. Results are validating with experimental test results.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"185 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133940841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158185
O. Kilit, Alper Yontar
A rough terrain adaptive rover using a novel suspension system with extremely high mobility is described. By using a multi stage type of a well-known bogie system, a rover gains a high level of adaptability to rough terrain. A novel method to model the rover path which doesn't require any surface modeling tool of rough terrain is represented. Two tilting angles - measured about both longitudinal and lateral axes of the rover body - are taken into consideration as stability criteria. Through the computer simulation, the kinematics model of the mobile robot moving on a randomly generated rough terrain is verified.
{"title":"Stability of a new mars rover with multi-stage bogie mechanism","authors":"O. Kilit, Alper Yontar","doi":"10.1109/RAST.2009.5158185","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158185","url":null,"abstract":"A rough terrain adaptive rover using a novel suspension system with extremely high mobility is described. By using a multi stage type of a well-known bogie system, a rover gains a high level of adaptability to rough terrain. A novel method to model the rover path which doesn't require any surface modeling tool of rough terrain is represented. Two tilting angles - measured about both longitudinal and lateral axes of the rover body - are taken into consideration as stability criteria. Through the computer simulation, the kinematics model of the mobile robot moving on a randomly generated rough terrain is verified.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"283 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133975362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158274
Secil Karatay, F. Arıkan, O. Arikan
The ionosphere can be characterized with its electron density distribution which is a complex function of spatial and temporal variations, geomagnetic, solar and seismic activity. An important measurable quantity about the electron density is the Total Electron Content (TEC) which is proportional to the total number of electrons on a line crossing the atmosphere. TEC measurements enable monitoring variations in the space weather. Global Positioning System (GPS) and the network of world-wide receivers provide a cost-effective solution in estimating TEC over a significant proportion of global land mass. In this study, five earthquakes between 2003–2008 that occurred in Japan with different seismic properties, and the China earthquake in May 2008 are investigated. The TEC data set is investigated by using the Kullback-Leibler Divergence (KLI), Kullback-Leibler Distance (KLD) and L2-Norm (L2N) which are used for the first time in the literature in this context and Cross Correlation Function (CCF) which is used in the literature before for quiet day period (QDP), disturbed day period (DDP), periods of 15 days before a strong earthquake (BE) and after the earthquake (AE). In summary, it is observed that the CCF, KLD and L2N between the neighbouring GPS stations cannot be used as a definitive earthquake precursor due to the complicated nature of earthquakes and various uncontrolled parameters that effect the behavior of TEC such as distance to the earthquake epicenter, distance between the stations, depth of the earthquake, strength of the earthquake and tectonic structure of the earthquake. KLD, KLI and L2N are used for the first time in literature for the investigation of earthquake precursor for the first time in literature and the extensive study results indicate that for more reliable estimates further space-time TEC analysis is necessary over a denser GPS network in the earthquake zones.
{"title":"Investigation of hourly and daily patterns for lithosphere-ionosphere coupling before strong earthquakes","authors":"Secil Karatay, F. Arıkan, O. Arikan","doi":"10.1109/RAST.2009.5158274","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158274","url":null,"abstract":"The ionosphere can be characterized with its electron density distribution which is a complex function of spatial and temporal variations, geomagnetic, solar and seismic activity. An important measurable quantity about the electron density is the Total Electron Content (TEC) which is proportional to the total number of electrons on a line crossing the atmosphere. TEC measurements enable monitoring variations in the space weather. Global Positioning System (GPS) and the network of world-wide receivers provide a cost-effective solution in estimating TEC over a significant proportion of global land mass. In this study, five earthquakes between 2003–2008 that occurred in Japan with different seismic properties, and the China earthquake in May 2008 are investigated. The TEC data set is investigated by using the Kullback-Leibler Divergence (KLI), Kullback-Leibler Distance (KLD) and L2-Norm (L2N) which are used for the first time in the literature in this context and Cross Correlation Function (CCF) which is used in the literature before for quiet day period (QDP), disturbed day period (DDP), periods of 15 days before a strong earthquake (BE) and after the earthquake (AE). In summary, it is observed that the CCF, KLD and L2N between the neighbouring GPS stations cannot be used as a definitive earthquake precursor due to the complicated nature of earthquakes and various uncontrolled parameters that effect the behavior of TEC such as distance to the earthquake epicenter, distance between the stations, depth of the earthquake, strength of the earthquake and tectonic structure of the earthquake. KLD, KLI and L2N are used for the first time in literature for the investigation of earthquake precursor for the first time in literature and the extensive study results indicate that for more reliable estimates further space-time TEC analysis is necessary over a denser GPS network in the earthquake zones.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134044892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158266
B. Agrawal
The current imaging spacecraft design trend is for higher imaging performance, allowing very low jitter. Vibration sources on spacecraft include reaction or momentum wheels, control moment gyros (CMG), solar drive motors, thruster firing, cryogenic coolers and slew maneuvers. Several techniques have been developed to reduce jitter. One technique is to increase damping of the spacecraft support structure to reduce vibration response by adding passive and/or active damping. The second technique is to introduce isolation between vibration source and the spacecraft. The third technique is to isolate the optical payloads from the spacecraft. The fourth technique is to reduce jitter in the optical beam by using fast steering mirrors. For spacecraft requiring the very low jitter, a combination of these techniques is used. This paper discusses briefly all these jitter control techniques.
{"title":"Jitter control for imaging spacecraft","authors":"B. Agrawal","doi":"10.1109/RAST.2009.5158266","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158266","url":null,"abstract":"The current imaging spacecraft design trend is for higher imaging performance, allowing very low jitter. Vibration sources on spacecraft include reaction or momentum wheels, control moment gyros (CMG), solar drive motors, thruster firing, cryogenic coolers and slew maneuvers. Several techniques have been developed to reduce jitter. One technique is to increase damping of the spacecraft support structure to reduce vibration response by adding passive and/or active damping. The second technique is to introduce isolation between vibration source and the spacecraft. The third technique is to isolate the optical payloads from the spacecraft. The fourth technique is to reduce jitter in the optical beam by using fast steering mirrors. For spacecraft requiring the very low jitter, a combination of these techniques is used. This paper discusses briefly all these jitter control techniques.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126468909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158200
T. Sharma, R. Young, C. Chatwin, P. Birch
Space has often been referred too as the final frontier. It is the curiosity of what lies beyond our planet that drives us to turn to the skies. This quest for knowledge and the chance of travelling to the heavens has compelled people to devote their lives to space science, innovation and analysis of our ever-expanding universe. Today the most significant impact of rocketry comes in the form of manned spaceflight. Vehicles like the Space Shuttle and Soyuz began the trend of greater commercialization of manned rocketry, enabling widespread access to space.
{"title":"Low cost propulsion systems for the developing world","authors":"T. Sharma, R. Young, C. Chatwin, P. Birch","doi":"10.1109/RAST.2009.5158200","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158200","url":null,"abstract":"Space has often been referred too as the final frontier. It is the curiosity of what lies beyond our planet that drives us to turn to the skies. This quest for knowledge and the chance of travelling to the heavens has compelled people to devote their lives to space science, innovation and analysis of our ever-expanding universe. Today the most significant impact of rocketry comes in the form of manned spaceflight. Vehicles like the Space Shuttle and Soyuz began the trend of greater commercialization of manned rocketry, enabling widespread access to space.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130796571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158295
E. Oland, Alexander Aas, Tor Marius Steihaug, S. V. Mathisen, Frank R. Vedal
In this paper we present a design methodology for attitude determination and control systems for picosatellites. It is based on the ECSS documentations and shows through a practical example how the ECSS standard can be applied to a picosatellite project.
{"title":"A design guide for attitude determination and control systems for picosatellites","authors":"E. Oland, Alexander Aas, Tor Marius Steihaug, S. V. Mathisen, Frank R. Vedal","doi":"10.1109/RAST.2009.5158295","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158295","url":null,"abstract":"In this paper we present a design methodology for attitude determination and control systems for picosatellites. It is based on the ECSS documentations and shows through a practical example how the ECSS standard can be applied to a picosatellite project.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134147411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158291
F. Guim, I. Rodero, E. Ozalp, E. Chester
While numerous global initiatives exist to address the potential hazards posed by volcanic eruption events and assess impacts from a civil security viewpoint, there is still no single, unified, international system of early warning and hazard tracking for eruptions. Numerous gaps exist in the risk reduction cycle, from data collection, to data processing, and finally dissemination of salient information to relevant parties. As part of the International Space University's Space Studies Program during summer 2008, a detailed gap analysis of the state of volcano disaster risk reduction was undertaken. Using this analysis as a basis, a novel framework to deal with all the identified gaps is proposed as an outcome of this study. This paper presents the principal innovations concerning the data and information processing within this work. The name of the framework was chosen to be VIDA to abbreviate ‘Volcanic Activity Processing of Observation and Remote Sensing Data Integrated Data-Sharing and Analysis’. In order to present this framework, it is shown how different high performance computing resources can be orchestrated in order to support fast and efficient tools that would support VIDA in mitigating the risk posed by volcanic eruptions and other natural hazards. Furthermore, how the system could be used by describing different use cases is also presented in this paper.
{"title":"A novel framework for a unified international system of volcano early warning and hazard tracking","authors":"F. Guim, I. Rodero, E. Ozalp, E. Chester","doi":"10.1109/RAST.2009.5158291","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158291","url":null,"abstract":"While numerous global initiatives exist to address the potential hazards posed by volcanic eruption events and assess impacts from a civil security viewpoint, there is still no single, unified, international system of early warning and hazard tracking for eruptions. Numerous gaps exist in the risk reduction cycle, from data collection, to data processing, and finally dissemination of salient information to relevant parties. As part of the International Space University's Space Studies Program during summer 2008, a detailed gap analysis of the state of volcano disaster risk reduction was undertaken. Using this analysis as a basis, a novel framework to deal with all the identified gaps is proposed as an outcome of this study. This paper presents the principal innovations concerning the data and information processing within this work. The name of the framework was chosen to be VIDA to abbreviate ‘Volcanic Activity Processing of Observation and Remote Sensing Data Integrated Data-Sharing and Analysis’. In order to present this framework, it is shown how different high performance computing resources can be orchestrated in order to support fast and efficient tools that would support VIDA in mitigating the risk posed by volcanic eruptions and other natural hazards. Furthermore, how the system could be used by describing different use cases is also presented in this paper.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122004130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158227
I. Bayir
Over the past decade the commercial remote sensing industry has experienced significant technological change and improved market penetration. New sensor Technologies in space systems offer new information capabilities.
{"title":"A glimpse to future commercial spy satellite systems","authors":"I. Bayir","doi":"10.1109/RAST.2009.5158227","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158227","url":null,"abstract":"Over the past decade the commercial remote sensing industry has experienced significant technological change and improved market penetration. New sensor Technologies in space systems offer new information capabilities.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124640648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-11DOI: 10.1109/RAST.2009.5158204
U. Hasirci, A. Balikci
This paper deals with the design, fabrication and test of a laboratory scale prototype 50 m/s coilgun-type electromagnetic launcher. It presents a comprehensive design guideline, explains the implementation process, and shows and briefly discusses the test results.
{"title":"Design, implementation and test of a coilgun-type electromagnetic launcher prototype","authors":"U. Hasirci, A. Balikci","doi":"10.1109/RAST.2009.5158204","DOIUrl":"https://doi.org/10.1109/RAST.2009.5158204","url":null,"abstract":"This paper deals with the design, fabrication and test of a laboratory scale prototype 50 m/s coilgun-type electromagnetic launcher. It presents a comprehensive design guideline, explains the implementation process, and shows and briefly discusses the test results.","PeriodicalId":412236,"journal":{"name":"2009 4th International Conference on Recent Advances in Space Technologies","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120957496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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