1. |
- Bodin, Per, et al.
(author)
-
Guidance, navigation, and control experiments on the PRISMA in-orbit test bed
- 2007
-
In: 58th International Astronautical Congress, IAC-07-C1. - 9781605601502 ; , s. 4461-4470
-
Conference paper (peer-reviewed)abstract
- PRISMA will demonstrate Guidance, Navigation and Control strategies for advanced autonomous formation flying and rendezvous. The Swedish Space Corporation (SSC) is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB). The project is further supported by the German Aerospace Center (DLR), the Technical University of Denmark (DTU), and the French Space Agency (CNES). PRISMA consists of two spacecraft: MAIN and TARGET. The MAIN satellite is 3-axis stabilized and has full 3D delta-V maneuverability that is independent of the spacecraft's attitude. The TARGET satellite has a simplified, yet 3-axis stabilizing, magnetic attitude control system and no orbit maneuver capability. This paper presents the PRISMA Guidance, Navigation, and Control (GNC) subsystem. The paper gives a mission summary and an overview of the GNC subsystem with its hardware and software configuration. It also explains how the orbit control functions contain advanced fuel optimal Model Predictive Control (MPC). It is shown how the GNC software is developed using model based automatic coding technology implemented with Matlab/Simulink. The paper then summarizes the different GNC experiments to be performed by SSC. Finally, an overview of the test approach for the subsystem is given.
|
|
2. |
- Bodin, Per, et al.
(author)
-
PRISMA : an in-orbit test bed for guidance, navigation, and control experiments
- 2009
-
In: Journal of Spacecraft and Rockets. - : American Institute of Aeronautics and Astronautics (AIAA). - 0022-4650 .- 1533-6794. ; 46:3, s. 615-623
-
Journal article (peer-reviewed)abstract
- This paper presents system-level hardware-in-the-loop real-time simulation results for three different guidance, navigation, and control experiments designed for in-flight demonstration on the PRISMA formation-flying satellite mission. The mission consists of two spacecraft: Main and Target The Main satellite has full orbit control capability, whereas Target is attitude-controlled only. Launch is planned for November 2009. The simulation results presented demonstrate the feasibility and readiness for flight as well as the expected in-flight performance. The three experiments include Global Positioning System and vision-based formation flying for two spacecraft in both passive and forced motion. In addition to these simulation results, the paper gives an overview of the PRISMA mission in general and the guidance, navigation, and control experiments in particular. The hardware-in-the-loop real-time test environment is also presented.
|
|
3. |
- D'Amico, Simone, et al.
(author)
-
Autonomous formation keeping and reconfiguration for remote sensing spacecraft
- 2009
-
In: 21st International Symposium on Space Flight Dynamics.
-
Conference paper (peer-reviewed)abstract
- This paper is devoted to the realistic demonstration of a complete Guidance, Navigation and Control (GNC) system for formation flying spacecraft in Low Earth orbit (LEO). Numerous technical novelties in the areas of formation flying guidance, GPS-based relative navigation, and impulsive relative orbit control have made this possible, but the primary contribution of this research work stems from the design and implementation of a comprehensive formation flying system through the successful integration of various techniques. This research has led to the full development, testing and validation of the GNC flight code to be embedded in the on-board computer of the Main spacecraft of the Swedish PRISMA technology demonstration. Furthermore key guidance and control algorithms presented here are going to be demonstrated for the first time on-board the German TanDEM-X formation flying mission. Overall this paper focuses on realistic application cases closely related to upcoming formation flying missions. The intention is to realize a practical and reliable way to a technology which is discussed and studied since decades but is still confined in research laboratories. Hardwarein- the-loop real-time simulations including flight computers show that simple techniques, which exploit the natural orbit motion to full extent, can meet the demanding requirements of the long-term close formation flying.
|
|
4. |
- Nylund, Annette, 1961-
(author)
-
Learning at Work and Productivity in Swedish Business Firms : Based on the Swedish MEADOW Survey 2009/2010
- 2017
-
Licentiate thesis (other academic/artistic)abstract
- The background of the thesis is the ongoing struggle for better understanding of driving forces for economic growth. Some important and rewarding new steps have been taken the last decades in the research of economic growth theory. For example, the theory includes not only the use of technology but also the creation and implementation of new technology entwined with management and learning practices at work. However, the development of knowledge on the matter can be described as slow. The explanation is argued to be the lack of data, which complicates and prevents the development of theory. The lack of data and the intertwined dependence with the development of theory in the matter constitutes the starting point for the research in the thesis.The purpose of this thesis is to contribute to the development of measures of management of work and learning practices at work that can be used in productivity models. The analyses are based on the micro-level data from the Swedish MEADOW Survey 2009/2010, at Statistics Sweden. Factor and regression analysis are performed, other analytical techniques are also used.Some key findings of how management and learning practices at work can be described and measured show that the business firms use the different practices in bundles. The findings indicate synergy effects on performance when more than one management and learning practice is applied. Two different management approaches are tested, both models predict productivity. However, there is a difference in the productivity model a such when it includes the two management approaches; the measure of the contemporary use has a better fitness then the theoretical model. Focus and delimitations of research questions in the forthcoming doctoral dissertation are discussed, see Future Research – the Logic Next Step, in Chapter 6. Final Reflections.
|
|
5. |
- Nylund, Annette, 1961-
(author)
-
Lärande i arbetet : indikatorer för att mäta lärande i arbetet med relevans för produktivitet och innovativitet
- 2023
-
Doctoral thesis (other academic/artistic)abstract
- Idag kan inget land i världen helt beskriva sin ekonomiska utveckling. Anledningen är att information om hur företag bedriver sin verksamhet saknas i det gemensamma internationella systemet för uppföljning. Information om lärande i arbetet behöver finnas med i national-räkenskaperna. Detta eftersom informationen har visat sig vara av avgörande betydelse för att på ett rättvist sätt belysa utvecklingen. Statistiken måste kompletteras med en återkommande undersökning som mäter lärande i arbetet baserad på data som samlas in på organisatorisk nivå i företag och andra organisationer. Avhandlingens syfte är att bidra till utvecklingen av statistik genom att presentera indikatorer som belyser lärande i arbetet med hög relevans för produktivitet och innovativitet. Teori-genomgången och analyserna i avhandlingen visar att det är viktigt att skilja på olika delar av lärande i arbetet. Därför har tre delindikatorer skapats: arbetstagarnas lärande (individuellt lärande) och arbetsorganisation (deltagande/decentralisering) samt företagens övriga struk-turella förutsättningar för lärande (strukturellt lärande). Delindikatorerna har olika betydelse för produktivitet och innovativitet. Den samlade slutsatsen är dock att alla typer av företag har nytta av lärande i arbetet eftersom lärandet bidrar till innovativitet och produktivitet, det visar analyserna. Resultaten visar också att alla typer av företag har förutsättningar att utveckla och använda praktiker för lärande i arbetet. Alla företag har också behov av lärande i arbetet inte minst på grund av att strukturomvandlingen berör alla typer av verksamheter. Lärande i arbetet har blivit en nyckelfaktor för både arbetstagares utveckling och attraktionskraft på arbetsmarknaden och företagens konkurrenskraft.Två svenska enkätundersökningar har använts i analyserna. De är Meadow 2009 (881 företag) och Nulägesundersökningen NU 2015 (1272 företag). Enkäterna är baserade på Meadow Guidelines arbetsgivarenkät som syftar till att samla in data på organisatorisk nivå om lärande arbetsorganisationer (Meadow Consortium, 2010). Enkätdata har matchats med innovations-data samt registerdata som beskriver företagens övriga verksamhetsförutsättningar och ekonomiska resultat. Analyserna i avhandlingen (och andra studier baserade på Meadow data) visar på robusta resultat baserade på beprövade data.För Sveriges del finns det inte längre några tillräckligt vägande skäl att vänta på gemensamma beslut inom Europa, OECD eller FN för att ta fram statistik om lärande i arbetet. Sverige föreslås ta egna initiativ och utveckla data om lärande i arbetet. Dels för att mäta och följa den del av livslångt kontinuerligt lärande som sker i arbetet, dels för att Sverige är ett av de länder i världen där konkurrenskraft bygger på hög kvalitet i produktionen, vilket kräver kontinuerligt lärande i arbetet och information om dessa investeringar. Statistiken och indikatorerna förväntas användas inom ett flertal forsknings- och policyområden.
|
|
6. |
- Nylund, Annette, 1961-, et al.
(author)
-
Ånyo frågan om lärande i arbetet: Konsekvenser för innovativitet och produktivitet
-
Other publication (other academic/artistic)abstract
- In Sweden, endogenous forces in companies are decisive for productivity. It is thirty years since the breakthrough in economic theory. Still, there is a lack of knowledge about their relationship with innovativeness and productivity. The shortcomings are partly due to a lack of data. Here, we take the operationalization of indicators that highlight learning at work a step further compared to the previous article in Arbetsmarknad_&_Arbetsliv. We present factor analysis that reveals learning patterns at work and regression analysis that validates the relevance of the indicators for innovation and productivity based on a representative sample of companies in Swedish business.
|
|
7. |
|
|