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Garg, K. & Emami, R. (2019). Balloon Ascent Prediction: Comparative Study of Analytical, Fuzzy and Regression Models. Advances in Space Research, 64(1), 252-270
Open this publication in new window or tab >>Balloon Ascent Prediction: Comparative Study of Analytical, Fuzzy and Regression Models
2019 (English)In: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 64, no 1, p. 252-270Article in journal (Refereed) Published
Abstract [en]

The ascent prediction of high-altitude zero-pressure stratospheric balloons is an important aspect of targeted test flight. Prediction of the balloon ascent rate is the prerequisite for many of the flights as it helps in planning ballasting and valving manoeuvres. In this paper, a standard analytical model, a fuzzy model and a statistical regression model are developed and compared to predict the zero-pressure balloon ascent. The flight data is extracted from the Esrange balloon service system for zero-pressure balloons with different payload capability, and several potential explanatory variables are computed for every sampled climbed segment. For the fuzzy modelling approach, a fuzzy c-mean clustering algorithm is used for system identification and prediction. For the regression approach, a Gaussian process regression is used, and principal component analysis is applied for finding the significant inputs. The result shows that the data driven approaches are more efficient than the standard analytical model.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Stratospheric balloon, Analytical model, Fuzzy model, Clustering, Regression model, Gaussian process regression
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-73398 (URN)10.1016/j.asr.2019.03.035 (DOI)000472126800019 ()
Note

Validerad;2019;Nivå 2;2019-07-10 (johcin)

Available from: 2019-04-03 Created: 2019-04-03 Last updated: 2019-07-10Bibliographically approved
Satpute, S. & Emami, R. (2019). Concurrent Station Keeping and Momentum Management of Geostationary Satellites. The Journal of the astronautical sciences
Open this publication in new window or tab >>Concurrent Station Keeping and Momentum Management of Geostationary Satellites
2019 (English)In: The Journal of the astronautical sciences, ISSN 0021-9142Article in journal (Refereed) Epub ahead of print
Abstract [en]

This article discusses a convex-optimization-based planning method for a geostationary satellite to determine station keeping and momentum unloading maneuvers concurrently. The proposed optimization algorithm incorporates a dual-rate prediction model to address the time scaling difference between the coupled slow orbital and fast attitude dynamics. The use of combined prediction model in the optimization problem facilitates to include state constraints accounting for the desired orbital and momentum unloading requirements. Maneuver plans are determined by solving a convex optimization problem in a receding horizon control form. The main objective of the proposed algorithm is to minimize fuel consumption while managing the stored momentum, in order to maintain a satellite in a tight station keeping window and nadir pointing attitude configuration. Numerical simulations are performed to validate the proposed optimization algorithm in terms of fuel consumption and constraint enforcement.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Concurrent maneuver planning, Geostationary satellites, Convex optimization, Nonintersecting thrusters, Electric propulsion system
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-73910 (URN)10.1007/s40295-019-00159-2 (DOI)2-s2.0-85065701623 (Scopus ID)
Available from: 2019-05-13 Created: 2019-05-13 Last updated: 2019-06-25
Nieto-Peroy, C. & Emami, R. (2019). CubeSat Mission: From Design to Operation. Applied Sciences, 9(15), Article ID 3110.
Open this publication in new window or tab >>CubeSat Mission: From Design to Operation
2019 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 9, no 15, article id 3110Article in journal (Refereed) Published
Abstract [en]

The current success rate of CubeSat missions, particularly for first-time developers, may discourage non-profit organizations to start new projects. CubeSat development teams may not be able to dedicate the resources that are necessary to maintain Quality Assurance as it is performed for the reliable conventional satellite projects. This paper discusses the structured life-cycle of a CubeSat project, using as a reference the authors’ recent experience of developing and operating a 2U CubeSat, called qbee50-LTU-OC, as part of the QB50 mission. This paper also provides a critique of some of the current poor practices and methodologies while carrying out CubeSat projects.

Place, publisher, year, edition, pages
Basel: MDPI, 2019
Keywords
CubeSat, miniaturized satellite, nanosatellite, small satellite development
National Category
Aerospace Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-75438 (URN)10.3390/app9153110 (DOI)
Note

Validerad;2019;Nivå 2;2019-08-13 (johcin)

Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-13Bibliographically approved
Emami, R., Bazzocchi, M. C. F. & Hakima, H. (2019). Engineering design pedagogy: a performance analysis. International journal of technology and design education
Open this publication in new window or tab >>Engineering design pedagogy: a performance analysis
2019 (English)In: International journal of technology and design education, ISSN 0957-7572, E-ISSN 1573-1804Article in journal (Refereed) Epub ahead of print
Abstract [en]

Cornerstone design courses have become a major part of engineering curricula, where students with different personality types and learning styles work together to design, develop, build, and demonstrate the functionality of a prototype within the duration of a term. This study analyzes student and team performance against gender, personality types, and learning styles in a second-year engineering design course. Further, the correlations between several assessment mechanisms are studied, and the effects of three different instructional design approaches on students’ performance are explored. Data have been collected on student performance and psychometrics, including marks, gender, personality type, and learning style from 2001 to 2018. To identify students’ personality types and learning styles, Myers–Briggs Type Indicators (MBTI) and Neil Fleming’s Learning VARK tests were administered. To evaluate students’ performance in the course, a number of assessment mechanisms have been defined. Several statistical methods are used to analyze data, and to determine correlation between datasets. Over nearly two decades of marks, gender, MBTI, and VARK data for 2637 students are presented for an engineering design course. The results demonstrated that there was no significant difference in performance across most assessments based on gender or gender distribution on a team. A better performance was observed from VK bimodal and quadmodal learning styles in most assessment mechanisms. Further, certain MBTI groups, namely, judging types outperformed their peers in engineering design assessments, with interesting interplay between MBTI dimensions for specific assessments and team dynamics. Traditional assessment mechanisms, such as engineering notebook and design proposals, are shown to be good predictors of student success. Lastly, scaffolded design activities and front-loading of lecture content were shown to be beneficial for student learning. There is negligible performance difference between female and male students in the engineering design course. Students whose preferred learning styles align with the assessment themes showed better performance in the course. The outcomes of this paper can be readily applied by instructors for design of assessment mechanisms, course materials, team formation, and instructional design.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Cornerstone design course, Assessment mechanisms, Instructional design, Personality types, Learning styles, Engineering design
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-73781 (URN)10.1007/s10798-019-09515-7 (DOI)
Available from: 2019-04-29 Created: 2019-04-29 Last updated: 2019-04-29
Browne Mwakyanjala, M., Emami, R. & Beek, J. v. (2019). Functional Analysis of Software-Defined Radio Baseband for Satellite Ground Operations. Journal of Spacecraft and Rockets, 56(2), 458-475
Open this publication in new window or tab >>Functional Analysis of Software-Defined Radio Baseband for Satellite Ground Operations
2019 (English)In: Journal of Spacecraft and Rockets, ISSN 0022-4650, E-ISSN 1533-6794, Vol. 56, no 2, p. 458-475Article in journal (Refereed) Published
Abstract [en]

This paper presents functional analysis and system specifications of a baseband system using software-defined radio (SDR) technology. The analysis is primarily based on the latest blue-book standards from the Consultative Committee for Space Data Systems (CCSDS). It covers telemetry, telecommand, and ranging, as well as some specifications of the associated physical layers. The SDR-based baseband system is envisioned to support ground operations in the form of a software-as-a-Service (SaaS) private cloud.

Place, publisher, year, edition, pages
American Institute of Aeronautics and Astronautics, 2019
National Category
Signal Processing Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems; Signal Processing
Identifiers
urn:nbn:se:ltu:diva-73313 (URN)10.2514/1.A34333 (DOI)000463716400013 ()
Note

Validerad;2019;Nivå 2;2019-03-26 (johcin)

Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-04-17Bibliographically approved
Sadeghi, S. & Emami, R. (2019). Large-scale Altitude Distribution Profile of Auroral Parallel Electric Potentials: A Statistical Analysis of Cluster Data. Advances in Space Research, 64(2), 378-384
Open this publication in new window or tab >>Large-scale Altitude Distribution Profile of Auroral Parallel Electric Potentials: A Statistical Analysis of Cluster Data
2019 (English)In: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 64, no 2, p. 378-384Article in journal (Refereed) Published
Abstract [en]

It is generally believed that the heart of the Auroral Acceleration Region (AAR) is located between 5000 and 8000 km altitude above the auroral oval. Various altitude distribution profiles are suggested by different theories, including the transition layer model, which predicts that the strongest electric fields can be found at about 1 RE, and can vary depending on the plasma and geomagnetic conditions. However, there have been no specific experimental results that cover regions both below and well above such altitude. This paper presents a method for obtaining such a profile from AAR satellite crossings, applies it to a data set gathered from 116 Cluster spacecraft encounters with acceleration potential structures, and discusses the results. The crossings cover an altitude range between 0.63 RE and 2.9 RE. The outcome is the first empirical altitude distribution profile of the auroral acceleration potentials. The results suggest that the region within the altitude range of 0.9245 RE and 1.158 RE statistically contains 30% of the total potential, which is the largest fraction of the parallel potentials among all altitude segments of the same size. The altitude which equally divides the distribution of acceleration potentials was found at 1.076 RE (6863 km). The obtained parallel potential distribution is in agreement with both the magnetic mirror force theory and the transition layer model, and can hence provide a proper baseline for future missions to the AAR.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Auroral acceleration region, Auroral electric potential structures, Multi-spacecraft, Cluster data
National Category
Natural Sciences Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-73585 (URN)10.1016/j.asr.2019.03.043 (DOI)000472699000006 ()2-s2.0-85064015424 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-07-12 (johcin)

Available from: 2019-04-11 Created: 2019-04-11 Last updated: 2019-07-12Bibliographically approved
Muralidharan, V. & Emami, R. (2019). Rendezvous and Attitude Synchronization of a Space Manipulator. The Journal of the astronautical sciences, 66(1), 100-120
Open this publication in new window or tab >>Rendezvous and Attitude Synchronization of a Space Manipulator
2019 (English)In: The Journal of the astronautical sciences, ISSN 0021-9142, Vol. 66, no 1, p. 100-120Article in journal (Refereed) Published
Abstract [en]

The control of a spacecraft equipped with a six-degree-of-freedom robot manipulator is studied in this paper. The objective is to rendezvous and synchronize with a satellite to facilitate inspection, servicing or de-orbiting. The space manipulator dynamics model with global parameterization on the configuration manifold is derived and used for designing asymptotically-stable control laws, so that they are valid globally in the configuration manifold. The control system consists of a sliding-mode rendezvous controller as well as a geometric attitude synchronization and a model-based servo control for the robot manipulator. The gains of the sliding-mode controller dictate a user-defined upper-bound on the thrust force. The attitude synchronization controller, concurrently with the rendezvous controller, is capable of micro-orbiting the space manipulator around spinning or tumbling satellites. It is observed through the simulations that the controller consumes limited amount of propellant, and it is feasible to use it for either a re-fueling (larger mass) or a de-orbiting (smaller mass) space manipulator.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Space manipulator, Spacecraft rendezvous, Attitude synchronization, Spacecraft control
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-74973 (URN)10.1007/s40295-019-00162-7 (DOI)000472234200006 ()2-s2.0-85065742039 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-25 (johcin)

Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2019-08-15Bibliographically approved
Roos, T. & Emami, R. (2018). A Framework for Autonomous Heterogeneous Robot Teams. In: : . Paper presented at 15th International Conference on Control, Automation, Robotics and Vision, ICARCV 2018; Singapore; 18-21 November 2018.
Open this publication in new window or tab >>A Framework for Autonomous Heterogeneous Robot Teams
2018 (English)Conference paper (Refereed)
Identifiers
urn:nbn:se:ltu:diva-72844 (URN)10.1109/ICARCV.2018.8581303 (DOI)000459847700146 ()
Conference
15th International Conference on Control, Automation, Robotics and Vision, ICARCV 2018; Singapore; 18-21 November 2018
Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-04-12
Bazzocchi, M. C. F. & Emami, R. (2018). Asteroid detumbling for redirection missions. In: 2018 IEEE Aerospace Conference: . Paper presented at 2018 IEEE Aerospace Conference, AERO 2018, Big Sky, United States, 3-10 March 2018. IEEE Computer Society
Open this publication in new window or tab >>Asteroid detumbling for redirection missions
2018 (English)In: 2018 IEEE Aerospace Conference, IEEE Computer Society, 2018Conference paper, Published paper (Refereed)
Abstract [en]

In order to accomplish most asteroid redirection missions, rotational control of the asteroid body is required. Small near-Earth asteroids tend to exhibit a significant range of rotational and tumbling properties. This work provides an analysis of asteroid detumbling using a formation of spacecraft. Through an orbiter and three landed thruster spacecraft, a low-thrust detumbling maneuver is performed on two illustrative asteroids. The asteroid scenarios are designed such that they reflect the characteristics of possible redirection scenarios. In particular the geometries, densities, angular velocities, and masses of the asteroids are adjusted according to available asteroid data to provide two unique redirection scenarios. The asteroid and spacecraft specifications are outlined, as well as the formulations for the detumbling maneuver. The results of the maneuver are discussed along with the key detumbling parameters and timeframe required.

Place, publisher, year, edition, pages
IEEE Computer Society, 2018
Series
IEEE Aerospace Conference Proceedings, ISSN 1095-323X
National Category
Aerospace Engineering Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-70311 (URN)10.1109/AERO.2018.8396607 (DOI)000474397402038 ()2-s2.0-85049829162 (Scopus ID)978-1-5386-2014-4 (ISBN)
Conference
2018 IEEE Aerospace Conference, AERO 2018, Big Sky, United States, 3-10 March 2018
Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2019-08-16Bibliographically approved
Anthony, N. & Emami, R. (2018). Asteroid engineering: The state-of-the-art of Near-Earth Asteroids science and technology. Progress in Aerospace Sciences, 100, 1-17
Open this publication in new window or tab >>Asteroid engineering: The state-of-the-art of Near-Earth Asteroids science and technology
2018 (English)In: Progress in Aerospace Sciences, ISSN 0376-0421, E-ISSN 1873-1724, Vol. 100, p. 1-17Article in journal (Refereed) Published
Abstract [en]

This paper presents a comprehensive review of the science and technology of accessing near-Earth asteroids (NEAs), or making them accessible, for obtaining both information and resources. The survey is divided into four major groups of NEA study, namely a) discovery (population estimation and detection), b) Exploration (identification and characterization), c) deflection and redirection, and d) mining (prospecting, excavation, processing, refining, storage.). Recent research and development advancements from both industry and academia are discussed in each group, and certain specific future directions are highlighted. Some concluding remarks are made at the end, including the need for creating new educational programs to train competent engineers and researchers for the taskforce in the new field of asteroid engineering in near future

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-68944 (URN)10.1016/j.paerosci.2018.05.001 (DOI)000440530200001 ()2-s2.0-85047055779 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-08-06 (rokbeg)

Available from: 2018-05-28 Created: 2018-05-28 Last updated: 2018-08-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4977-6339

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