ESA Plug and Play related activities in the Onboard Data Systems Division

Transcription

1 ESA Plug and Play related activities in the Onboard Data Systems Division Chris Taylor Head of Onboard Communications unit September 2010 NSO meeting P&P - NSO 17/09/2010 TEC-ED Slide 1

2 Contents Introduction Context and motivation for standardisation and P&P CCSDS ECSS Savoir SpaceWire Prototyping Platform Planned activities P&P - NSO 17/09/2010 TEC-ED Slide 2

3 Introduction The Onboard Data Systems Division is the focus for developments related to the spacecraft Avionics: Microelectronics Computers and data handling Payload data processing Communication protocols A particular aspect of the Division is the promotion of standardisation in order to reduce costs and foster reuse. It is within this framework that plug and play activities have been initiated This presentation provides an overview of the P&P within the broader context of standardisation Note that there may be ESA P&P related activities not reported here P&P - NSO 17/09/2010 TEC-ED Slide 3

4 Context SMU PM RM Alarms PDHT Payload Instruments Payload Instruments PCDU SADM POWER S/S P/L C&C bus P/L BC 1553 BC TC Management TM Management OBT Management FDIR Management MdM Management AOCS Management Power Management Thermal Management Payload management CPDU TC Decoder TM Encoder MM Security Module P/F ON/OFF HLC S band RX S band TX TX TTC RF Sub-system Heaters OBT PPS SpaceWire Payload Instruments Thermistors Thermal P/F Discrete I/Os P/F Monitoring Mil-1553 bus P/L Essential Monitoring GPS STR CRS RW CSS MAG MTB Thrusters LV LV Tank Pt Payload Platform AOCS Sub-system Propulsion Sub-system P&P - NSO 17/09/2010 TEC-ED Slide 4

5 P&P - NSO 17/09/2010 TEC-ED Slide 5

6 Context The flight avionics is composed of a large number of units interconnected by a plethora of interfaces The spacecraft procurement process is based on an industrial prime responsible for overall spacecraft integration and several equipment manufactures Industrial primes typically have their own proprietary design to which equipment manufactures must comply, different primes have different requirements This results in additional costs as all parties must adapt existing equipment and software to a unique implementation which must then be tested and validated P&P - NSO 17/09/2010 TEC-ED Slide 6

7 Approach to standardisation The obvious answer to improving the situation is the generation and application of standards across multiple projects While the use of standards has always been key to ESA procurements, in the last few years the level and effort dedicated to standardisation has significantly increased There are four main forums in which these efforts are taking place: The CCSDS The ECSS The SpaceWire Working group The Savoir initiative P&P - NSO 17/09/2010 TEC-ED Slide 7

8 CCSDS (Consultative Committee for space data standards)

9 CCSDS The CCSDS is well know for the generation of spacelink centric protocol standards used by the majority of space agencies A few years ago the SOIS (standard onboard interface services) group was established to examine the onboard Avionics system with a view to standardising the communication services for onboard data transfer This group has defined a generic onboard architecture with an associated set of communication services Recommendations for the onboard subnet have been released and work is progressing on application related services and P&P Prototyping is underway P&P - NSO 17/09/2010 TEC-ED Slide 9

10 CCSDS SOIS - architecture Application Layer Mission Specific Applications Communication Management Application Support Layer Transfer Layer Subnetwork Layer CMD & Data Acquisition Services Transport Protocol Network Protocol Packet Service Time Access Service Memory Access Service File & Packet Store Services Synchronisation Service Message Transfer Service Device Discovery Service Device Enumeration Service Test Service Datalink Convergence Protocols P&P - NSO 17/09/2010 TEC-ED Slide 10 Milbus SpaceWire CAN Wireless

11 SOIS End-to-end Context Application Application Application PUS Services Flight Applications PUS Packets Command and Data Acquisition Services Message Transfer Services SOIS Application Support Layer Services Packet service Memory access service Synchronisation service File Transfer Service CFDP Test Service File & Packet Store Services Device Discovery Service Time Access Services SOIS Subnetwork Services TM/TC Spacelink File and packet store Sensors & Actuators Payloads Time Source Onboard sub-systems P&P - NSO 17/09/2010 PUS Services TEC-ED Slide 11 Ground Applications Standard services

12 Why Apply Plug-and-Play to Space Systems? Aims: Application portability Hardware interoperability Application Standardise only the important bits Interfaces and basic mechanisms Plug-and-Play Leave application and device open for innovation Hardware Device Plug-and-play is not necessarily dynamic at run time View plug-and-play across the development cycle P&P - NSO 17/09/2010 TEC-ED Slide 12

13 Plug-and-Play in SOIS Device interfaces standardised at data link level ECSS-E-ST-50-12C (SpaceWire) ECSS-E-ST-50-13C (MIL-STD-1553) Converging towards standard link-level protocols E.g. ECSS-E-ST-50-52C (RMAP) However, must work with existing devices Must not require major changes to device interfaces beyond above standards Should present standard functional interface to applications Must be semantically standard, otherwise applications will not be interoperable P&P - NSO 17/09/2010 TEC-ED Slide 13

14 Application Application Application Software Bus Applications Device Virtualisation Service Optional EDS Device Enumeration Service Device Access Service SOIS Subnetwork Device Discovery Service Subnetwork Packet or Memory Access Service Subnetwork Management and Configuration Subnetwork Plug-and-Play Protocol Subnetwork Protocol Implementations Subnetwork Implementation P&P - NSO 17/09/2010 TEC-ED Slide 14 Optional EDS Hardware Device Hardware

15 Use of Electronic Data Sheets (EDS) An electronic data sheet can be used to help produce DAS and DVS for our device Hand coded, auto-coded or combination EDS must fully describe the device Typically, if something is in a traditional data sheet it will be needed in an EDS EDS must describe: Subnetwork service usage and Device-Specific Access Protocol for DAS DAS usage, unit conversions etc for DVS EDS will be supplied with, or on, device P&P - NSO 17/09/2010 TEC-ED Slide 15

16 EDS Technologies SOIS Proof-of-Concept is engaged in a preliminary study, looking at: IEEE 1451 Mature, well used standard; highly extensible and very descriptive. Tied to underlying interface standards physically and semantically; largely binary based (non-human readable). XTCE Large, capable standard; XML-based (human-readable); some documentation available. Standard is too large and not intended for use in describing devices. AFRL xteds (public release) Well structured, fairly extensible standard already in use for space plug-and-play; XML-based (human-readable). Reliant on non-standardised data model for semantics; documentation limited. Study not yet complete P&P - NSO 17/09/2010 TEC-ED Slide 16

17 ECSS (European Cooperation for space Standardization)

18 ECSS The ECSS standards are applied to all ESA programs and are therefore a key factor in improving the level of avionics standardisation ECSS both develops and adopts standards At the data link level three standards are of relevance: Milbus (ECSS-E-ST-50-13C) Released CANbus (ECSS-E-ST-50-15C,..) Draft SpaceWire (ECSS-E-ST-50-12C,..) Released These are all driven being driven by the SOIS subnetwork services specifications and cover physical, electrical and data link protocols A forth standard (ECSS-E-ST-50-14C) covers discrete interfaces for simple point to point communication P&P - NSO 17/09/2010 TEC-ED Slide 18

19 SAVOIR Initiative (Space Avionics Open Interface architecture)

20 SAVOIR Goals Streamline the development of avionics systems: increase cost-efficiency and reduce development time Standardise avionics: building blocks and standard interface definitions Maximise synergy between ongoing initiatives at ESA, National Agencies and industry and help concentrate all the efforts towards the shared objectives Software architectures, SW Engineering Tools and methods, System Composition Onboard communications, processors, data systems, SOIS std AOCS sensor and actuator harmonisation P&P - NSO 17/09/2010 TEC-ED Slide 20

21 SAVOIR Areas of Work Architectures SW architectures HW architectures Comms architectures Functional chains Interfaces Identification of key interfaces Standard interface specifications Standard protocols Building Blocks Identification of functional generic BBs Development and qualification of BBs Methods and Tools Specification of Avionics Specification, development and testing of BBs Composition of Avionics from BBs End-to-end system level V&V P&P - NSO 17/09/2010 TEC-ED Slide 21

22 SAVOIR Advisory Group motivation To bring the full visibility of what is going on in the area of avionics developments performed by the Agencies towards the Industry To get a consensus with all stake-holders on development priorities and standards evolution To share as far as possible a common vision of future avionics architecture such that avionics components road-maps can have the greatest support from the Industry To enhance the coherence in the area of avionics of all initiatives (e.g ECI) and organizations (e.g Eurospace) through a shared knowledge of the information by all main stake-holders of the Avionics field P&P - NSO 17/09/2010 TEC-ED Slide 22

23 SAVOIR Advisory Group: Membership SAG: Space Agencies: ESA (Avionics System Group (Control, Data and SW Systems) CNES DLR 1. System integrators/ industrial primes: TAS Astrium SSC OHB 2. SW and Eq. Suppliers RUAG Space Terma Selex Galileo SAG Working Groups: Open also to other space Agencies, system integrators and avionics software or equipment suppliers that can contribute to the WG objectives P&P - NSO 17/09/2010 TEC-ED Slide 23

24 OBC architectures - evolution Decentralization of functionalities (more than one RTU), Miniaturization of the OBC core (SoC, extreme packaging), New Interfaces (e.g CAN, Digital sensor Bus, smart sensors, HSSL,Space Fibre). P/L Bus OBC/CDMU/SMU MIL-STD-1553B SpW CAN ECSS-E-ST-50-13C ECSS-E-ST-50-12C, ECSS-E-ST-50-15dr P&P - NSO 17/09/2010 TEC-ED Slide 24 Platform Bus RTU RTU Discrete RS Digital sensor Bus (I2C, SPI, ) Wireless Sensors & Actuators (T, AOCS, Propulsion, )

25 SpaceWire

26 PnP at the SpaceWire Working Group SpaceWire PnP was introduced as topic discussed at the SpaceWire Working Group in 2007 Glenn Rakow from NASA, GSFC is convener for SpW PnP The subgroup discussions on SpW PnP have resulted in the SpaceWire Protocol Definition Issue 2.1 This document has been reviewed and discussed during the last WG meeting Some backwards compatible changes to the SpaceWire standard required by SpW PnP are intended to be included in the upcoming revision of the standard P&P - NSO 17/09/2010 TEC-ED Slide 26

27 Planned SpW PnP related activities (1) Network Discovery Protocols Objectives: TRP activity ITT planned for 2010 Definition, implementation and test of the network discovery protocol and plug and play techniques over a SpaceWire network Develop a SpaceWire network PnP test bed Validation of the SpW PnP protocol to prepare standardisation P&P - NSO 17/09/2010 TEC-ED Slide 27

28 Planned SpW PnP related activities (2) SpaceWire node interface IP core Objectives: Draft TRP WP , ITT planned for 2012 Development of a comprehensive, configurable SpaceWire node IP-core Features among others PnP protocol support SpaceWire node interface IP-core is planned to be distributed by ESA's IP core service for ESA mission P&P - NSO 17/09/2010 TEC-ED Slide 28

29 Prototyping Platform

30 RASTA Reference Architecture System Test bed for Avionics RASTA is composed of a set of commercial hardware and software and is R&D prototyping, including building blocks It is not built to flight standards but it is representative in terms of processor, operating system, interfaces and associated protocols It takes input from the following sources: SAVOIR for Software/hardware architectures and building block identification CCSDS for TM/TC, file transfer protocols and onboard communications services ECSS for interfaces and onboard protocols ESA for Processor (LEON), IP cores and key software P&P - NSO 17/09/2010 TEC-ED Slide 30

31 RASTA Development ESA Initial specification Gaisler/ Aeroflex Internal Investment Maintenance Prototype code Hardware Software RTEMS (EDISOFT) ECSS Mil, Can SpW, CFDP Commercial System cpc I User Community Large number of systems sold world wide: EADS, TAS, RUAG, SciSys, P&P - NSO 17/09/2010 Spacebel, TEC-ED ESA Slide 31 etc TM TC SpW AT697 mezzanine 1553, CAN, SpaceWire GR-AT 697 Process or Board SpW CAN MIL ETH GR-232 I/O Board

32 RASTA Basic Elements cpci cpci TM TC AT697 mezzanine 1153, CAN, SpaceWire GR-AT 697 Processor Board GR-232 I/O Board AT697 mezzanine 1153, CAN, SpaceWire GR-AT 697 Processor Board GR-232 I/O Board SpW SpW CAN MIL ETH SpW CAN MIL ETH Development and test environment Development and test environment SpW CAN MIL ETH Platform Processor TM/TC Front end ETH CFDP Reference Payload Processor CAN RTU MIL SpW CAN Mass Memory Additional Building blocks ETH P&P - NSO 17/09/2010 TEC-ED Slide 32 Ground System

33 Summary ESA has a clear interest in the use of plug and play but progress is relatively slow for a number of reasons ESA mainly develops scientific satellites with inherently long lead times Industrial primes already have well established platforms and associated V&V processes The need to amortise development costs Existing busses and I/Fs are well known, proven and available in flight quality components The usual institutional resistance to change Nevertheless there are a number of initiatives already in progress that will open the door for a plug and play approach, it s just a matter of when! P&P - NSO 17/09/2010 TEC-ED Slide 33

34 Future studies A number of R&D studies are planned for the next round of TRP: Evaluation of electronic data sheets Deploying Plug and play avionics SpaceWire plug and play protocol development Standardisation of digital interfaces and sensors RS-422 protocol standard for AOCS equipments Standard software architecture and software bus PUS to SOIS mapping. P&P - NSO 17/09/2010 TEC-ED Slide 34

35 Back-up

36 Key SOIS Services Device Virtualisation Service (DVS) Provides an abstract interface based on device class Device Access Service (DAS) Used by DVS Provides command and acquire capabilities using a Device-Specific Access Protocol (DSAP) P&P - NSO 17/09/2010 TEC-ED Slide 36