Sichere Werkzeugketten und werkzeugunterstütztes Assessment - Verwendung komplexer Werkzeugketten für die Entwicklung und Bewertung sicherheitsrelevanter Software

Eine stark wachsende Zahl eingebetteter elektronischer Systeme implementiert sicherheitsrelevante Funktionen. Diese Funktionen werden zunehmend in Software implementiert. Die einschlägigen Normen zur Funktionalen Sicherheit erfordern den Einsatz von „vertrauenswürdigen“ Softwareentwicklungswerkzeugen und Werkzeugketten. Diese Arbeit leitet einen generischen, projektunabhängigen Ansatz für die Qualifizie-rung von Softwarewerkzeugen her, die bei der Entwicklung sicherheitsrelevanter Systeme eingesetzt werden. Auf Basis dieser Methodik wird in einem zweiten Schritt ein Vorgehen entwickelt, dass es ermöglicht, die Bewertung der Funktionalen Sicherheit (Safety Assessment) werkzeugunterstützt durchzuführen. Dies führt zu einer signifikanten Effizienzsteigerung bei der Begutachtung sicherheitstechnischer Systeme

High Torque Wheels for agile Satellite Maneuvers - in Orbit Experiences and future Steps with Recuperation of Energy

Agility is a necessary skill for several tasks. This applies in particular to remote sensing applications, but is also useful for optical communication from satellite to ground. While discussing a new reconnaissance satellite, the need for suitable actuators for agile maneuvers was identified several years ago. Developments for robotics at DLR (e.g. ROKVIS experiment on board the ISS (2004-2011) resulted in the possibility to further develop the reaction wheel principle for the special application "high torque" for fast accelerations. This was in competition with the widespread use of control momentum gyros (CMG). It was decided to equip the small satellite BIROS (launch 2016) with three “High Torque Wheels” (HTW) as additional technological payload. With this down-scaled version of the HTWs, the proof of the concept should be made under real conditions in space. This included various agile satellite maneuvers such as for “in track stereo”, scanning up to 5 parallel image strips on ground or switching between different targets on ground. This of course required changes to the ACS and the power supply system, which was a reuse of technology from the DLR small satellite TET-1. The attitude control system (ACS) uses several “attitude modes” for a comfortable and autonomous attitude control of the satellites in space. This was extended by a special “Fast Slew Mode”, which was developed for fast maneuvers using HTWs. The standard satellite slew rate is 0.5 degrees per second with a freely selectable single slew axis. A fast slewing maneuver intends to reorient the satellite by up to 30 degrees within 10 seconds. Actually however, the satellite achieved angular speeds of up to 10 degrees per second in space. A fast slew maneuver is finished, when all the HTWs are nearly stopped and the default ACS actuators took over the remaining angular momentum. This process of momentum exchange between the actuator systems was one important aspect of investigations. Another test case was the usage of these 3 experimental HTWs as actuator of the ACS. After successful completion of the first experimental phase in orbit the work will be continued by improving the fast slew maneuver algorithms and by preparing a second experimental phase in space including active payload cameras in the defined image scenarios. The HTW will be equipped now with an energy recuperation system storing electrical energy instead of kinetic energy within a spinning CMG

High Torque Wheels for agile Satellite Maneuvers - in Orbit Experiences and future Steps with Recuperation of Energy

Agility is a necessary skill for several tasks. This applies in particular to remote sensing applications, but is also useful for optical communication from satellite to ground. While discussing a new reconnaissance satellite, the need for suitable actuators for agile maneuvers was identified several years ago. Developments for robotics at DLR (e.g. ROKVIS experiment on board the ISS (2004-2011) resulted in the possibility to further develop the reaction wheel principle for the special application "high torque" for fast accelerations. This was in competition with the widespread use of control momentum gyros (CMG). It was decided to equip the small satellite BIROS (launch 2016) with three “High Torque Wheels” (HTW) as additional technological payload. With this down-scaled version of the HTWs, the proof of the concept should be made under real conditions in space. This included various agile satellite maneuvers such as for “in track stereo”, scanning up to 5 parallel image strips on ground or switching between different targets on ground. This of course required changes to the ACS and the power supply system, which was a reuse of technology from the DLR small satellite TET-1. The attitude control system (ACS) uses several “attitude modes” for a comfortable and autonomous attitude control of the satellites in space. This was extended by a special “Fast Slew Mode”, which was developed for fast maneuvers using HTWs. The standard satellite slew rate is 0.5 degrees per second with a freely selectable single slew axis. A fast slewing maneuver intends to reorient the satellite by up to 30 degrees within 10 seconds. Actually however, the satellite achieved angular speeds of up to 10 degrees per second in space. A fast slew maneuver is finished, when all the HTWs are nearly stopped and the default ACS actuators took over the remaining angular momentum. This process of momentum exchange between the actuator systems was one important aspect of investigations. Another test case was the usage of these 3 experimental HTWs as actuator of the ACS. After successful completion of the first experimental phase in orbit the work will be continued by improving the fast slew maneuver algorithms and by preparing a second experimental phase in space including active payload cameras in the defined image scenarios. The HTW will be equipped now with an energy recuperation system storing electrical energy instead of kinetic energy within a spinning CMG

Is self-determined motivation associated with the effects of an intervention aimed to increase physical activity and exercise levels? An 80-day follow-up

Objective: State-of-the-art technologies, for instance smart watches and smartphones, have the potential to positively influence physical activity and exercise in sedentary populations. Psychological factors, such as self-determined (SD) motivation, might influence the impact state-of-the-art technologies have on level of physical activity and exercise. The aim of this study was to investigate if self-determined motivation influences an intervention on both physical activity (PA) and exercise in a sedentary population. Methods: 16 participants (men = 5, women = 11) with a self-reported low level of PA over the last year and predominantly sedentary jobs volunteered to participate in the study. PA data (steps and exercise time) were collected over an 80-day period using a wrist-worn accelerometer (Apple-watch and iPhone). Motivation was measured with the Behavioral Regulation in Exercise Questionnaire-2. At the start of the study, each participant completed the questionnaire and received their Apple-watches. Data analysis: All PA and exercise data were recorded through the Apple-watch and via Health App. Data for PA (steps) and exercise time were then extracted and aggregated to daily totals. Statistical analysis: Group means and standard deviations were calculated. A linear regression analysis was used to analyze the relationship between exercise time, PA, and SD, the R2 value effect size (ES) was used to estimate the magnitude of the differences. All data analyses were performed in MatLab (software, R2016b). Results/findings: SD motivation (3.9±0.9) had a medium (R2 = 0.09) but not statistically significant (p = .26) effect on the amount of moderate to high-intensity exercise time (33.3±39.6 minutes) during the 80-day period. There was no statistically significant effect (R2 = 0.003, p = .84) of SD on PA (12953±7717 steps). Conclusions: Given the small sample size, achieving a medium effect size has meaningful significance despite not achieving statistical significance. This result suggests that self-determined motivation effects the amount of daily exercise but not PA in a sedentary population. Combining technology and other strategies (e.g., motivational interviewing, coaching) to promote behavior change is promising, and these interventions should include theoretically derived behavior change techniques and take level of SD motivation into account

Der Kleinsatellit BIROS in der FireBIRD Mission

Dieser Bericht enthält eine detaillierte Abhandlung des gesamten Entwicklungsprozesses des Bi-spektralen Infrarot-Optischen Systems (BIROS) in der FireBIRD Mission, beginnend mit der wissenschaftlichen Aufgabenstellung zur Detektion und Bewertung von Hochtemperaturereignissen (HTE) aus dem Weltraum über die Auslegung des IR-Kamerasystems als primäre Nutzlast von BIROS, seiner Sekundärnutzlasten, des BIROS Satellitenbusses, dem Nutzerinterface zur Datenanforderung bis hin zu ausgewählten Anwendungsbeispielen der FireBIRD Datenprodukte. Es wird neben der technischen Beschreibung der Subsysteme des Satelliten und der bi-spektralen IR-Kamera, mit Bändern im mittleren Infrarot (MIR) und im thermalenInfrarot (TIR) die adaptive Anpassung der radiometrischen Dynamik der IR-Signaltrakte erklärt. Diese stellt ein Alleinstellungsmerkmal dar im Hinblick auf die bildhafte Erkennung und Bewertung von Feuern oder heißer Lava, welche Temperaturen zwischen 300 °C und 1300 °C erreichen, im sogenannten Sub-Pixelbereich. Anhand von verschiedenen Anwendungsbeispielen wird aufgezeigt, dass mit der IR-Kamera kleine Feuer von nur 10 m2 Ausdehnung zu erkennen sind und gleichzeitig bei der Beobachtung von riesigen Busch-bränden oder groß- flächigen Lavaströmen die IR-Kamera Signaltrakte nicht 'in die Sättigung' gehen, d.h. das Feuersignal nicht begrenzen. Aus der Beobachtung HTE einerseits und von NormalTemperatur-Phänomenen (NTP) konnten die adaptiven Dynamikbereiche für die MIR- und TIRBänder der Kamera nachgwiesen werden, die von keinem anderen IR-Kamaerasystem eines Kleinsatelliten bekannt sind. Die mit BIROS gesammelten Erfahrungen erlauben Schlussfolgerungen für zukünftige Kleinsatellitenmissionen zur räumlich und radiometrisch höher auflösenden Erdbeobachtung im MIR und TIR