International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Today’s flight test programs are experiencing increasing demands for a greater number of high-rate digital parameters, competition for spectrum space, and a need for operational flexibility in flight test instrumentation. These demands must be met while meeting schedule and budget constraints. To address these various needs, the Boeing Integrated Defense System (IDS) Flight Test Instrumentation group in St. Louis has developed an onboard processing capability for use with airborne instrumentation data collection systems. This includes a first-generation Onboard Processor (OBP) which has been successfully used on the F/A-18E/F Super Hornet flight test program for four years, and which provides a throughput of 5 Mbytes/s and a processing capability of 480 Mflops (floating-point operations per second). Boeing IDS Flight Test is also currently developing a second generation OBP which features greatly enhanced input and output flexibility and algorithm programmability, and is targeted to provide a throughput of 160 Mbytes/s with a processing capability of 16 Gflops. This paper describes these onboard processing capabilities and their benefits.

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ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / The U.S. Army Research Laboratory (ARL) is developing an onboard instrument and telemetry system to obtain measurements of the 30mm MK310 projectile's in-flight dynamics. The small size, high launch acceleration, and extremely high rates of this projectile create many design challenges. Particularly challenging is the high spin rate which can reach 1400 Hz at launch. The bandwidth required to continuously transmit solar data using the current method for such a rate would leave no room for data from other sensors. To solve this problem, a data compression scheme is implemented that retains the resolution of the solar sensor data while providing room in the telemetry frame for other measurements.

The satellite avionics platform has been developed in cooperation with Airbus and is called „Future Low-cost Platform“ (FLP). It is based on an Onboard Computer (OBC) with redundant processor boards based on SPARC V8 microchips of type Cobham Aeroflex UT699. At the University of Stuttgart a test bench with a real hardware OBC and a fully simulated satellite is available for testing real flight scenarios with the Onboard Software (OBSW) running on representative hardware. The test bench as later the real flying satellite "Flying Laptop" – is commanded from a real Ground Control Centre (GCC). The main challenges in the FLP project were - Onboard computer design, - Software design and - Interfaces between platform and payloads In the course of industrialization of this FLP platform technology for later use in satellite constellations, Airbus has started to set up an in-house test bench where all the technologies shall be developed. The initial plan is to get first core elements of the FLP OBSW ported to the new dual-core processor and the new Space Wire(SpW) routing network. The plan also has an inclusion of new Mission Control Software with which one can command the OBC. The new OBC has a dual core processor Cobham Gaisler GR712 and hence, all the payload and related functionality are to be implemented only in a second core which involves a lot of low-level task distribution. The consequent SpW router network application and dual-core platform/payload OBSW sharing are entirely new in the field of satellite engineering.

Recent advances in spaceborne GPS technology have shown significant advantages in many aspects over conventional technologies. For instance, spaceborne GPS can realize autonomous orbit determination with significant savings in spacecraft life cycle, in power, and in mass. At present, the onboard orbit determination in real time or near-real time can typically achieve 3D orbital accuracy of metres to tens metres with Kalman filtering process, but 21st century space engineering requires onboard orbit accuracy of better than 5 metres, and even sub-metre for some space applications. The research focuses on the development of GPS-based autonomous orbit determination techniques for spacecraft. Contributions are made to the field of GPS-based orbit determination in the following five areas: Techniques to simplify the orbital dynamical models for onboard processing have been developed in order to reduce the computional burden while retaining full model accuracy. The Earth gravity acceleration approximation method was established to replace the traditional recursive acceleration computations. Results have demonstrated that with the computation burden for a 55× spherical harmonic gravity model, we achieve the accuracy of a 7070× model. Efforts were made for the simplification of solar & lunar ephemerides, atmosphere density model and orbit integration. All these techniques together enable a more accurate orbit integrator to operate onboard. Efficient algorithms for onboard GPS measurement outlier detection and measurement improvement have been developed. In addition, a closed-form single point position method was implemented to provide an initial orbit solution without any a priori information. The third important contribution was made to the development of sliding-window short-arc orbit filtering techniques for onboard processing. With respect to the existing Kalman recursive filtering, the short-arc method is more stable because more measurements are used. On the other hand, the short-arc method requires less accurate orbit dynamical model information compared to the long-arc method, thus it is suitable for onboard processing. Our results have demonstrated that by using the 1 ~ 2 revolutions of LEO code GPS data we can achieve an orbit accuracy of 1 ~ 2 metres. Sliding-window techniques provide sub-metre level orbit determination solutions with 5~20 minutes delay. A software platform for the GPS orbit determination studies has been established. Methods of orbit determination in near-real time have been developed and tested. The software system includes orbit dynamical modelling, GPS data processing, orbit filtering and result analysis modules, providing an effective technical basis for further studies. Furthermore a ground-based near-real time orbit determination system has been established for FedSat, Australia's first satellite in 30 years. The system generates 10-metre level orbit solution with half-day latency on an operational basis. This system has supported the scientific missions of FedSat such as Ka-band tracking and GPS atmosphere studies within the Cooperative Research Centre for Satellite System (CRCSS) community. Though it is different from the onboard orbit determination, it provides important test-bed for the techniques described in previous section. This thesis focuses on the onboard orbit determination techniques that were discussed in Chapter 2 through Chapter 6. The proposed onboard orbit determination algorithms were successfully validated using real onboard GPS data collected from Topex/Poseidon, CHAMP and SAC-C satellites.

Bidirectional onboard chargers (OBCs) are becoming mainstream commercial charging equipment for electric vehicles (EVs) because of their compactness, flexibility, and demand-response capabilities for power backup. This thesis focuses on the novel phase shift (PS) modulation techniques for efficiency improvement for bidirectional OBCs, including two-stage onboard chargers (TSOBCs) and single-stage onboard chargers (SSOBCs). A comprehensive overview and investigation of the state-of-the-art solutions of bidirectional OBCs are presented. It reviews the current industrial status, industrial applications, and future trends and challenges. A detailed overview of the promising topologies for bidirectional OBCs, including two-stage and single-stage structures, is also discussed in this thesis. Traditional PS modulation has been widely used in the back-end DC/DC converters of the TSOBCs because of its simple implementation. However, it is challenging to keep high efficiency at boundary operating points within wide specifications. Therefore, to improve efficiency at the boundary point for TSOBCs, the hybrid multiple phase shift (HMPS) modulation technique with minimal peak current optimization is presented to maximize the zero-voltage switching (ZVS) range. Compared to traditional single phase shift (SPS) modulation, the experimental results verify that the presented HMPS modulation strategy provides 1%-2% higher efficiency at the boundary points. On the other hand, an improved compact SSOBC topology and novel PS modulation techniques are proposed. Since the traditional PS modulation is challenging for AC/DC converters to keep a unity power factor (PF), novel PS modulation techniques are presented for the proposed SSOBC. Firstly, a sinusoidal single phase shift (SSPS) modulation introduces a sinusoidal phase shift to maintain a high PF and high efficiency within a wide operating point. However, due to the high current at the zero-crossing point of the grid voltage of the SSPS modulation, the novel adaptive sinusoidal single phase shift (ASSPS) modulation is presented to address this issue, which reduces conduction loss and increases efficiency. Secondly, based on the ASSPS modulation, the adaptive sinusoidal extended phase shift (ASEPS) modulation with minimal peak current optimization is presented to introduce one more degree of freedom to extend the ZVS flexibility, which reduces switching loss. Moreover, the minimal peak current optimization reduces transformer current, further decreasing conduction losses. Therefore, the power loss is minimized. Finally, this thesis presents the general design guideline of a 6 kW Silicon Carbide (SiC)-based bidirectional SSOBC, contributing to the further development of bidirectional SSOBC application. Experimental results verify the operating principle and high PF of the proposed SSPS, ASSPS, and ASEPS modulation. 1 kW experimental testing has validated that the peak efficiency is 95.3% with ASSPS modulation and 95.9% with ASEPS modulation. Compared to the existing pulse width modulation (PWM), the ASSPS modulation increased efficiency by 1.1%, and ASEPS modulation further increased by 1.7%. / Thesis / Doctor of Philosophy (PhD)

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / The HDF5 (Hierarchical Data Format) data storage family is an industry standard format that allows data to be stored in a common format and retrieved by a wide range of common tools. HDF5 is a widely accepted industry standard container for data storage developed by the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign. The HDF5 data storage family includes HDF-Time History, intended for data processing, and HDF-Packet, intended for real-time data collection; each of these is an extension to the basic HDF5 format, which defines data structures and associated interrelationships, optimized for that particular purpose. HDF-Time History, developed jointly by Boeing and NCSA, is in the process of being adopted throughout the Boeing test community and by its external partners. The Boeing/NCSA team is currently developing HDF-Packet to support real-time streaming applications, such as airborne data collection and recording of received telemetry. The advantages are significant cost reduction resulting from storing the data in its final format, thus avoiding conversion between a myriad of recording and intermediate formats. In addition, by eliminating intermediate file translations and conversions, data integrity is maintained from recording through processing and archival storage. As well, HDF5 is a general-purpose wrapper, into which can be stored processed data and other data documentation information (such as calibrations), thus making the final data file self-documenting. This paper describes the basics of the HDF-Time History, the extensions required to support real-time acquisition with HDF-Packet, and implementation issues unique to real-time acquisition. It also describes potential future implementations for data acquisition systems in different segments of the test data industry.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Wireless interfaces are becoming ubiquitous in terrestrial applications ranging from local area networking in business and commercial environments to large scale factory automation and process control. The pressure to develop these wireless interfacing techniques has come from the need to reduce cabling, reduce installation costs, and make it easier to extend network infrastructures. Concerns about electromagnetic compatibility, safety, reliability, and security have lead to the development of techniques and protocols that enable such wireless interfaces to be operated in electromagnetically harsh environments, without generating unacceptable interference, and providing reliable, dependable and secure data communications. On the face of it, the use of wireless interfaces onboard spacecraft looks like a good way of reducing the spacecraft harness mass and bulk. However, recent work by the European Space Agency has shown that, while harness reduction will undoubtedly be one benefit of using wireless interfaces, they offer many other benefits that will be more significant in the near future. Amongst these are significant advantages during integration and testing, the ability to retrofit and upgrade facilities, and cable replacement in moving structures such as robotic arms. In this paper we briefly survey the benefits of wireless interface technologies for spacecraft onboard use, and identify the challenges involved in adapting them for flight use. We then look at the considerations that should be taken into account in establishing the financial case for developing wireless interface technologies for flight applications.

Syftet med arbetet är att undersöka i vilken omfattning särbehandling av studenter förekommer till sjöss. Studiens syfte är också att kartlägga mönster, vad man blir utsatt för, av vem och bakomliggande orsaker. För studien valdes enkätundersökning som metod med personlig närvaro under insamlingen på plats ute hos målgruppen för att på så sätt säkerställa ett så omfattande underlag som möjligt. Respondenterna utgjordes av de båda fyraåriga sjökaptensprogrammens avgångsklasser i Kalmar respektive Göteborg. Resultatet visade att 51 % av respondenterna minst någon gång under sin praktiktid hade upplevt sig vara utsatta för särbehandling. Alla tillfrågade respondenter deltog i enkätundersökningen. Studien visar på att många studenter blivit utsatta för psykiska trakasserier och utanförskap från den ordinarie besättningen. Detta kan ha sin grund i hög arbetsbelastning, nedärvda attityder och brist på uppdaterad kunskap inom områden som till exempel ledarskap. Även skolornas ansvar lyfts fram som möjliga orsaker. / The study aimed to investigate the possible presence and extent of discrimination / harassment of students on onboard training and had its starting point in the debate about students' vulnerability which in 2014 was written about in the Swedish Shipping Gazette. The study's purpose was to identify patterns, such as what one is exposed to, by whom and underlying causes. For the study a questionnaire survey were selected as method. With personal attendance on site during the collection the aim was to ensure the broadest possible result. The target group consisted of the two graduating classes in the four-year master mariner-programs in Kalmar and Gothenburg. The results showed that 51 % of the surveyed respondents at least some time during their onboard training had experienced themselves victims of discrimination. The study showed that the students most likely to have been exposed to psychological harassment and exclusion from the regular crew.  This may be due to high workload, inherited attitudes and lack of updated skills in areas such as leadership. Even the schools responsibility is highlighted.

The aim for this thesis is to design a software library responsible for preventing, detecting, handling and logging faults caused by radiation in a representable flight computer system based on the Cobham Gaisler GR740 quad-core LEON4FT processor chip. The LEON processor family is commonly used in space applications and it is based on the open SPARC instruction set and has been extended with fault tolerant features to cope with both on-chip radiation effects as well as upsets in external memory. The new GR740 device introduces a new computer architecture with multiple buses as compared to previous chips, Level-2 cache and a memory scrubber accelerating fault mitigation in external SDRAM memories. As the processor system design keeps getting more complex it also requires software to handle more hardware and new events, including central handling and logging routines of faults. The report describes the analysis performed to identify sources of faults and proposed suitable mitigation techniques, the established software requirements and how they are translated into a software architecture, then implemented and finally demonstrated on hardware. Along with this, it is shown how the developed demonstrator application software library can be integrated into the RTEMS real-time operating system commonly used in European space missions. The results are based on the demonstrator execution, and the results show that the software is functionally working and validates that the performance of the scrubber matches the derived scrubbing timings. After the project is completed, the software library design will be evaluated for use in Cobham Gaisler’s payload computer platform for the GOMX-5 mission. Radiation upsets will be emulated by injecting faults while running the developed API on demonstrator applications. Furthermore, implementation of software into NASA cFS/cFE will be analysed.