Speaker
Description
Modular Avionic approaches have been around for 40 years but vary widely in implementation and the extent of both hardware and software levels of unification. The IMA concept, which replaces numerous separate processors and LRU with fewer, more centralized processing units, has led to significant weight reduction and maintenance savings in both military and commercial airborne platforms. Similar concepts have been developed for automotive (AUTOSAR) and in the industrial automation domain. Besides saving mass and volume the major driver in the industrial domains is cost both for development and maintenance.
Common to all these concepts is the use of standards for both hardware and software. Like in other domains space industry will have to cope with increasing system complexity but shorter development cycles and reduced budgets. Proven concepts from other domains need to be investigated, adapted and applied in space programs to meet the customer expectations wrt. quality, time and cost in a global market. Recent developments in space avionics like spaceVPX, and compact PCI Serial Space will help to achieve these objectives.
In this paper we present an approach how these modular computer concepts will help to develop high performance payload data processing computers with reasonable effort and at reasonable costs. Based on an use case for on-board space debris detection we discuss the different solutions and finally describe a modular payload data processing computer based on the CompactPCI Serial Space standard and a multicore CPU board.
As a result of 50 years of spaceflight, the attractive orbits around Earth are littered with derelict satellites, burnt-out rocket stages, discarded trash and other debris. In September 2012, the U.S. Space Surveillance Network tracked about 23,000 orbiting objects larger than 5-10 centimeters. By extrapolation it is estimated that there could be a total of 750,000 orbiting objects larger than 1 cm. The first step to avoid collisions is to detect potential objects that could impact a satellite. Space objects between 10cm in LEO and 30-100cm in GEO are typically monitored by a ground based space surveillance networks.
The ESA TRP activity "Streak Detection and Astrometric Reduction" (StreakDet) aimed at formulating and discussing suitable approaches for the detection and astrometric reduction of streaks in optical observations. Thus, the study provided the basis for potential space-based optical observations of objects in lower altitudes.
Processing is carried out in three main parts: segmentation,classification, and astrometry and photometry - as in most image analysis tasks. The aim of segmentation can be considered to be two fold: to reduce all unnecessary information from the image and to robustly extract all the desired features for further processing. The overall processing time reported in the final report of the study was 12300 ms. All processing was done on an Intel Xeon Quad Core CPU with a Clock speed of 2000MHz and 2 GByte of RAM.
The use case has been selected as it represents a full class of image processing applications. This includes image based navigation but also object detection in Earth observation images. In addition, many reference images either real or synthetic can be used as input and a reference implementation is also available.
The goal of the demonstrator described in this paper is to reduce the processing time to 1.5 seconds based on space qualifiable components.
The functionality described before needs to be implemented in software and hardware. Especially, the segmentation algorithm requires more processing power than what is available with conventional instruments controllers based on LEON2/3 processors. Therefore, new hardware and software architectures need to be investigated that go beyond the available solutions. The design space to implement the previously described functionality ranges from pure software implementations on single or manycore CPUs to full implementation in an FPGA or ASIC or anything in between.
In Germany Airbus together with Fraunhofer FOKUS, STI, Sysgo, TTTech and fortiss took a further step in order to develop an OMAC4S technology concept for space applications based on an DLR funded project called OBC-SA: While maintaining IMA segregation features, back plane solution (CPCI-S1 compliant) and the proprietary cabinet, a Satellite Deterministic Network and space domain (robotic) specific middleware API with system support services (ECSS-E-ST-70-41 compliant) and application support services ARINC653 compliant) were added. A 1Gbit switched Time Sensitive Ethernet data communication network is provided to connect all CPM (Core Processing Module) and other equipment on the spacecraft. For payload data processing where high processing performance is required the user can select among different CPUs. The NXP P4080 is the most promising solution when high speed data streams have to be processed as it provides a large number of CPU cores allowing parallel execution of tasks and many high speed links like PCIe lanes and 10Gbps Ethernet ports for transferring data from an instrument to data processing.
The algorithm has been implemented in Python under Linux operating system. The average processing time on the P4080 board is in the order of 4 to 5 seconds. Currently, the algorithm implemented in Python is converted into C and optimized to be executed on multicore computers using a tool chain from emmtrix Technologies. The final target architecture will be the P4080 board running PikeOS operating system. Results will be presented at the workshop.
| Paper submission | Yes |
|---|
