Validation System (EVS)

Transcription

1 Presentation of the Astrium EGSE Validation System (EVS) Compiled Clive Catley

2 Introduction document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. presentation gives an overview of the Astrium EGSE Validation System (known as EVS). The EVS is an ATE specifically designed for testing specialised spacecraft test equipment generically known as Electrical Ground Support Equipment (EGSE). The presentation provides background information on spacecraft testing (using the Gaia project as an example), which provides the justification for the EVS. Thereafter, an overview of the EVS Hardware and Software design is presented.

3 Spacecraft testing (GAIA)

4 Spacecraft testing document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. The GAIA spacecraft is essentially a massive digital camera (1 billion pixels). Astrium (as prime contractor) leads a large European consortium building the spacecraft for the European Space Agency. The spacecraft will be placed 1.5 million km beyond earth orbit and over a 5 year period provide a census (star map) of our galaxy over 1000 million stars.

5 Spacecraft testing (GAIA)

6 Spacecraft testing Typically for one-off science mission spacecraft, a FlatSat of the spacecraft is first built with a set of engineering model electronic units (identical to the flight models). is a test bed for validating the electrical interfaces, on-board software and closed-loop l control systems.

7 Spacecraft testing (GAIA)

8 PYRO/P PYRO/R BATTERY PCDU SVM 1553 T PLM 1553 T GAIA Spacecraft CDMU BC BC PW SpW MDE OSE FPA CPS PRIME EIU-A EIU-B SpaceWire CPS RDNT upropulsion PRIME MPE-A MPE-B VPU1-7 upropulsion RDNT GYRO 1A GYRO 1B GYRO 2A GYRO 2B GYRO 3A GYRO 3B SpaceWire Spacecraft testing FSS 1 FSS 2 FSS 3 DSA/BIPODS SpaceWire PacketWire STR1 STR2 PAA Test Cap LGA-1 LGA-2 LGA-3 CLOCKS PDHU CDU Transponder #1 Transponder #2 document is the property of Astrium. It shall not be communicated to third p

9 Spacecraft testing Typically a science spacecraft consists of a set of electrical units: The platform consisting of: Computer Electrical interface Power control unit Attitude & orbit control (gyros, star trackers, sun sensors, propulsion) RF subsystem (transponders, antennas) document is the property of Astrium. It shall not be communicated to third p

10 Spacecraft testing The platform consisting of: Instrument Instrument support units Payload processors

11 BSRB 3 3 Spacecraft testing document is the property of Astrium. It shall not be communicated to third p CCS User Workstation CCS U Workst User ation Central Check kout CC Wor CS User rkstation CCS User Workstation System (CCS) Server Datation IRIG-B Avionics SCOE Umbi ilical Rack DT SVM 1553 CLOCKS PLM 1553 SpaceWire SpaceWire

12 Spacecraft testing To support ground testing of the spacecraft specialised test equipment is required, typically: Solar array simulator Umbilical power & monitoring Battery simulator RF front end Avionics front end Spacecraft simulator Payload front ends Checkout system document is the property of Astrium. It shall not be communicated to third p

13 Spacecraft testing

14 Spacecraft testing

15 Spacecraft testing

16 Spacecraft testing There is a requirement that such test equipment must be validated prior to use. That is: all electrical interfaces to the spacecraft (and corresponding functions) must be tested before connection.

17 Spacecraft testing document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. One such test equipment is the Avionics front end which supplies interfaces to the spacecraft attitude control units, and in tandem with the spacecraft simulator is capable of simulating the units themselves. equipment has over 600 I/O interfaces of various types: Analog in/out Pulse generation Pulse acquisition RS , SpaceWire BUS interfaces Power simulators

18 It shall not be communicated to third p document is the property of Astrium. Why do we need an EVS? Previously, 2 options have been employed to validate EGSE: Procure EGSE with a built-in test facility. Validate manually using break-out boxes and stand- alone test equipment. Due to the extra software and hardware required for built-inin test implementation, option 1 can cost typically upward of 50k per equipment (or some 100 s k per project). Option 2 can typically take in the order of 2-3 days for complex equipments. With EGSE often re- located between various external test t facilities this can prove very costly, as validation must be repeated following any shipment.

19 EVS overview The EVS provides an option 3. It is designed to provide multiple generic test functions for validating spacecraft test equipment.

20 EVS Hardware Design

21 EVS overview It shall not be communicated to third p The EVS utilises PXI platform instrumentation where possible to provide a compact design. is essential as the EVS may be located in sites with difficult access such as inside thermal vacuum chambers or on the top of rocket launch towers. The software platform is LabWindows/CVI, chosen for its ease of use in instrument control and its familiarity as a development tool within Astrium. document is the property of Astrium.

22 EVS Hardware Design M Sy odular Power ystem N6700B

23 EVS Hardware Design At the core of the system is the switching. is provisioned by a 128 way interface for mixed signal switching to the test instrumentation. interface may also be re-configured to 2 50 way interfaces. From this interface any 1 or 2 pairs from equipment cables can be selected and routed to the test instruments. A second interface is via a 12A matrix to allow signal routing for power testing.

24 EVS Hardware Design document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. The EVS provides the following measurement facilities: 7 ½ digit DMM effectively doubling as an oscilloscope. Data Acquisition (digital, analog, isolated /non-isolated). Dynamic loading and measurement. Stimulation types: Function generation. Data generation (digital, analog, isolated /non-isolated). Power sources Dynamic power sources. Special test types: 1553 Reflective memory

25 Software Design document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. The software is designed such that the core system provides the majority of the test functionality required for multiple spacecraft projects, based on standard d I/O specified in spacecraft GDIR and common functions, such as power, protection testing, solar array simulation, etc. means any project utilising the system need only provide configuration information derived from the EGSE specifics and any specific development peculiar to the project.

26 Software Design The software design is presented below. The core system consists of a Test Manager (MMI) reading test configuration in from project specific Excel files.

27 Software Design The tests are executed by core test modules providing common application based tests.

28 Software Design or test modules designed specifically against project needs.

29 Software Design The test modules interface to an Instrument Driver Adaptation layer for specific instrument configuration (such as the switching).

30 Software Design.or directly to the COTS Instrument Driver Layer as required.

31 Software Design Test results are processed against limits defined in the test configuration files, and test reports created.

32 Software Design Manual control is provided utilising intuitive front panel GUI s, providing the capability of a general purpose test equipment.

33 Software Design Each project defines its test needs by providing Excel based configuration and limits files. EGSE Validation Pro-Forma (Avionics SCOE) document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. Avionics SCOE Cable Name Function ITB# 1 ITB (pos) ITB (neg) CCS Parameter1 MPS-STAT-MPE- LV-PT-A Operator Connect Cable 26 Connect SCOE cable SK10P01 to ITB2 via 25WS 1 MPS_LPTR-A.sig MPE_MPS_LPTRA 1 MPS_HPTR-A.sig MPE_MPS_HPTRA 1 MPS_HPLV-1A_OPEN.sig MPS_HPLV1A_OPEN_PW 1 MPS_HPLV-1A_CLOSE.sig MPS_HPLV1A_CLOSE_PW 1 MPS_HPLV-1A_STAT.sig MPS_HPLV1A_STAT Test No Signal Type Config1a Config1b LowLim1 HiLim1 0 SHP-ACQ SHP-GEN LV FCV RSA

34 Software Design document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. A separate Library is included which provides the communication protocols with the spacecraft test t equipment. Thus allowing the test modules to control and monitor the equipment functions. (Normally spacecraft test equipment communication protocols are based on packet messaging over LAN). The user front end is a simple GUI from which the operator simply selects the Excel file defining the test configuration and limits and starts the test. The EVS includes a built in self-test which provides validation of all instruments, switching and test modules.

35 Software Design

36 Conclusion document is the property of Astrium. It shall not be communicated to third Its content shall not be disclosed. The EVS offers an efficient and cost effective solution to meet tthe needs of spacecraft fttest tequipment validation. It provides accurate, repeatable validation testing in a time-effective manner, reducing setup times for spacecraft testing (particularly during intensive test periods on location). Example: The Avionics front end detailed here can be tested in less than 1 hour. It uses proven technology of which Astrium has widespread knowledge. Long term, it can save many k in EGSE costs (if otherwise built-in). It offers a test solution to existing equipment where otherwise none exists.