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Publications (10 of 91) Show all publications
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)
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: 2019-02-11
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)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: 2018-08-16Bibliographically 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
Bazzocchi, M. C. F. & Emami, M. R. (2018). Asteroid Redirection Mission Evaluation Using Multiple Landers. The Journal of the astronautical sciences, 65(2), 183-204
Open this publication in new window or tab >>Asteroid Redirection Mission Evaluation Using Multiple Landers
2018 (English)In: The Journal of the astronautical sciences, ISSN 0021-9142, Vol. 65, no 2, p. 183-204Article in journal (Refereed) Published
Abstract [en]

In this paper, a low-thrust tugboat redirection method is assessed using multiple spacecraft for a target range of small near-Earth asteroids. The benefits of a landed configuration of tugboat spacecraft in formation are examined for the redirection of a near-Earth asteroid. The tugboat method uses a gimballed thruster with a highly collimated ion beam to generate a thrust on the asteroid. The target asteroid range focuses on near-Earth asteroids smaller than 150 m in diameter, and carbonaceous (C-type) asteroids, due to the volatiles available for in-situ utilization. The assessment focuses primarily on the three key parameters, i.e., the asteroid mass redirected, the timeframe for redirection, and the overall system cost. An evaluation methodology for each parameter is discussed in detail, and the parameters are employed to determine the expected return and feasibility of the redirection mission. The number of spacecraft employed is optimized along with the electrical power needed for each spacecraft to ensure the highest possible return on investment. A discussion of the optimization results and the benefits of spacecraft formation for the tugboat method are presented.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-67476 (URN)10.1007/s40295-017-0125-5 (DOI)000433125400003 ()2-s2.0-85047416164 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-05-31 (rokbeg)

Available from: 2018-02-02 Created: 2018-02-02 Last updated: 2018-06-14Bibliographically approved
Satpute, S. & Emami, R. (2018). Concurrent co-location maneuver planning for geostationary satellites. Acta Astronautica
Open this publication in new window or tab >>Concurrent co-location maneuver planning for geostationary satellites
2018 (English)In: Acta Astronautica, ISSN 0094-5765, E-ISSN 1879-2030Article in journal (Refereed) Epub ahead of print
Abstract [en]

This paper details the development of a planning algorithm for multiple co-located geostationary satellites to perform station keeping and momentum unloading maneuvers concurrently. The objective is to minimize the overall fuel consumption while guaranteeing a safe separation distance between the satellites within a specific geostationary slot, as well as managing their stored angular momentum to maintain their nadir pointing orientation. The algorithm adopts the leader-follower architecture to define relative orbital elements of the satellites equipped with four gimbaled on-off electric thrusters, and solves a convex optimization problem with inequality constraints, including momentum unloading requirements, to determine the optimal maneuvers. The proposed algorithm is verified, in terms of fuel consumption, constraints enforcement and satellites performance, using numerical simulations that take into account dominant perturbations in the geostationary environment.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Concurrent maneuver planning, co-location, geostationary satellites, convex optimization, gimbaled thruster
National Category
Aerospace Engineering Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Onboard space systems
Identifiers
urn:nbn:se:ltu:diva-71323 (URN)10.1016/j.actaastro.2018.10.027 (DOI)
Available from: 2018-10-24 Created: 2018-10-24 Last updated: 2018-10-24
Pomares, J., Felicetti, L., Pérez, J. & Emami, R. (2018). Concurrent Image-based Visual Servoing with Adaptive Zooming for Non-cooperative Rendezvous Maneuvers. Advances in Space Research, 61(3), 862-878
Open this publication in new window or tab >>Concurrent Image-based Visual Servoing with Adaptive Zooming for Non-cooperative Rendezvous Maneuvers
2018 (English)In: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 61, no 3, p. 862-878Article in journal (Refereed) Published
Abstract [en]

An image-based servo controller for the guidance of a spacecraft during non-cooperative rendezvous is presented in this paper. The controller directly utilizes the visual features from image frames of a target spacecraft for computing both attitude and orbital maneuvers concurrently. The utilization of adaptive optics, such as zooming cameras, is also addressed through developing an invariant-image servo controller. The controller allows for performing rendezvous maneuvers independently from the adjustments of the camera focal length, improving the performance and versatility of maneuvers. The stability of the proposed control scheme is proven analytically in the invariant space, and its viability is explored through numerical simulations.

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-66538 (URN)10.1016/j.asr.2017.10.054 (DOI)000424179100008 ()
Note

Validerad;2018;Nivå 2;2018-02-09 (andbra)

Available from: 2017-11-10 Created: 2017-11-10 Last updated: 2018-02-22Bibliographically approved
Satpute, S. & Emami, R. (2018). Concurrent Manuever Planning for Geostationary Satellites. 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 >>Concurrent Manuever Planning for Geostationary Satellites
2018 (English)In: 2018 IEEE Aerospace Conference, IEEE Computer Society, 2018Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, a planning method is developed using convex optimization for concurrent station keeping and momentum unloading maneuvers of geostationary satellites equipped with on-off electric thrusters. Prediction models for coupled orbital and attitude dynamics are used for generating concurrent maneuver plans. Since the satellite's attitude dynamics is fast compared to the orbital dynamics, a dual-rate model is proposed for addressing time scale differences of the two coupled systems. Based on such a model, a convex optimization problem is formulated and solved in a receding horizon form, which minimizes the fuel consumption and the number of required maneuvers. The proposed algorithm is verified using numerical simulations, taking into account major perturbations in the geostationary environment. The performance of the proposed method is analyzed in terms of fuel consumption and constraint enforcement.

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-70080 (URN)10.1109/AERO.2018.8396498 (DOI)2-s2.0-85049857646 (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: 2018-07-05 Created: 2018-07-05 Last updated: 2018-08-16Bibliographically approved
Bazzocchi, M. C. F. & Emami, R. (2018). Formation of Multiple Landers for Asteroid Detumbling. Advances in Space Research, 62(3), 732-744
Open this publication in new window or tab >>Formation of Multiple Landers for Asteroid Detumbling
2018 (English)In: Advances in Space Research, ISSN 0273-1177, E-ISSN 1879-1948, Vol. 62, no 3, p. 732-744Article in journal (Refereed) Published
Abstract [en]

This work develops a method for ascertaining the landing locations and thruster orientations of a formation of multiple spacecraft on an irregular asteroid for discrete time optimal detumbling control, as a prerequisite to asteroid redirection. Asteroid geometries are known to be extremely irregular, especially for small asteroids, which are the typical targets for redirection missions. The method entails the modelling of asteroids as convex polyhedra with triangular facets, and computing the mass and inertial properties through the divergence theorem and Green’s theorem. Given the asteroid geometry, mass, and inertial properties, the feasible lander locations and thruster orientations are determined. The model ensures full attitude control of the asteroid, using multiple spacecraft with fixed-orientation, low-thrust modules, through measures imposed on the location and orientation of each thruster. A linear control scheme is employed to assess the time and fuel requirements of the asteroid detumbling maneuver, given feasible spacecraft formation configurations and thruster orientations. The method then assesses the detumbling time performance of each formation configuration to determine the discrete optimal landed formation configuration for a given asteroid. Simulations are performed to demonstrate the method using an irregular asteroid with characteristics derived from available asteroid data. Extensions of the method are further discussed in light of the results.

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-68778 (URN)10.1016/j.asr.2018.05.011 (DOI)000437076300017 ()2-s2.0-85047525147 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-06-25 (andbra)

Available from: 2018-05-18 Created: 2018-05-18 Last updated: 2018-07-23Bibliographically approved
Felicetti, L. & Emami, R. (2018). Image-based attitude maneuvers for space debris tracking. Aerospace Science and Technology, 76, 58-71
Open this publication in new window or tab >>Image-based attitude maneuvers for space debris tracking
2018 (English)In: Aerospace Science and Technology, ISSN 1270-9638, E-ISSN 1626-3219, Vol. 76, p. 58-71Article in journal (Refereed) Published
Abstract [en]

This paper proposes an image-based control scheme for tracking space debris using onboard optical sensors. The proposed strategy uses an onboard camera for detecting space debris. The camera is rigidly attached to the satellite; therefore specific attitude maneuvers need to be performed during different phases of the mission. First, the spacecraft orients its attitude to point the camera toward a fixed direction in space, and then when debris traces streak across the field of view of the camera, the spacecraft follows and tracks the motion of the debris. Finally, a disengagement maneuver is executed to stop the spacecraft rotation when the debris disappears from the camera field of view. The model and the developed control scheme take into account the typical characteristics of space-qualified cameras, and a Kalman filter is developed to reduce the effects of the camera noise, detect and predict the path of the debris in the image plane, and estimate the angular velocity of the spacecraft. The entire estimation/control scheme is then validated through numerical simulations, using a model of reaction wheels as the main attitude actuation system. The results demonstrate the viability of such maneuvers in a typical space debris surveillance mission scenario.

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-67554 (URN)10.1016/j.ast.2018.02.002 (DOI)000432510200006 ()2-s2.0-85042010623 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-03-05 (svasva)

Available from: 2018-02-07 Created: 2018-02-07 Last updated: 2018-06-08Bibliographically approved
Satpute, S. & Emami, R. (2018). Optimal maneuver planning for the co-location of geostationary satellites. In: : . Paper presented at 4th IAA Conference on Dynamics and Control of Space Systems, DYCOSS 2018; Changsha; China; 21-23 May 2018.
Open this publication in new window or tab >>Optimal maneuver planning for the co-location of geostationary satellites
2018 (English)Conference paper (Refereed)
Identifiers
urn:nbn:se:ltu:diva-72860 (URN)2-s2.0-85058946671 (Scopus ID)
Conference
4th IAA Conference on Dynamics and Control of Space Systems, DYCOSS 2018; Changsha; China; 21-23 May 2018
Available from: 2019-02-12 Created: 2019-02-12 Last updated: 2019-02-12
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-4977-6339

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