Developing NASA s Fault Management Guidebook for Deep Space Robotic Missions

Transcription

1 Developing NASA s Fault Management Guidebook for Deep Space Robotic Missions Lorraine Fesq and Raquel Jacome Jet Propulsion Laboratory, California Institute of Technology Flight Software Workshop December 16-18, 2014 California Institute of Technology Annapolis, MD Copyright 2014 California Institute of Technology. Government sponsorship acknowledged. The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

2 FM By Any Other Name Names for this discipline: ISHM, FP, IVHM, SHM, RM, FDIR, Hazards/Aborts/C&W, HUMS, PHM 2

3 : Developed NASA s Fault Management Handbook Goal Ameliorate schedule/cost/ predictability challenges of testing/ operating FM systems Improve reliability and safety of NASA s flight and ground systems Coalesce the FM field Scope Outline scoped to address needs of Agency crewed and robotic missions Robotic emphasis in Version 1, due to SMD co-funding Suggested use as companion to SE Handbook 3

4 Release of Draft FM Handbook Presenter Date Draft 1 Released July comments (NTSPO record) 283 dispositioned by Handbook Lead Ø Ø Easier comments that could be addressed individually were tackled first due to Handbook not representing diverse views of FM across NASA #"of"comments" 350# 300# 250# 200# 150# 100# 50# 0# Number"of"Comments"per"Center" 297# 220# 172# 73# 54# 10# 4# 3# JSC# GRC# GSFC# KSC/S&MA# MSFC# WSTF# ARC# JPL# 280# NESC# Current Status: Draft 2 released 4/9/12. Lesson Learned: Diverse FM views across NASA. Comments cannot be dispositioned by one person or one Center requires discussions/consensus among people in the discipline, across the Agency Plans: Refocused effort to develop chapter for each mission type, to be incorporated into NASA FM Handbook 4

5 Take 2: Developing a Deep Space FM Robotic Guidebook Motivation Ad hoc implementations and incomplete existing guidance Issues from attempt to develop NASA-wide FM Handbook (NASA-HDBK-1002) Final product will be applicable across NASA, but focused on FM for deep-space robotic missions Hosted on the NEN FM Community of Prac:ce web site Intent is to leverage existing guidance into a more structured and useful form Adding more why and how to current descriptions Funded by OCE 5

6 Perspec've: Other Organiza'ons are Developing FM Guidance Other organizations recognize the need to develop FM guidance for their teams and stakeholders APL SAE Developed a process description for fault protection June 2009 QY3-660, Fault Management Engineering Process Formed IVHM committee June 2010 to develop cornerstone aerospace Recommended Practice document IEEE Developed a book/standard on IVHM: Perspectives on an Emerging Field Developing a Prognostics and Health Management Standard Aerospace Corporation Developed guidelines for Earth-orbiting spacecraft Aerospace Report No. TOR-2009(8591)-14, Effective Fault Management Guidelines, 5 June 2009 Aerospace Report No. TOR-2012(1302)-13, Proposed Satellite System Safe Mode 6 Standard, August 1, 2012 (Draft)

7 FM Process and Phase Spider Diagrams Pre-Phase A Phase A Phase B Phase C Phase D Phase E KDP A KDP B KDP C MCR MDR PDR CDR SIR KDP D ORR KDP E Policy prelim final exceptions Architecture prelim final upd exceptions Conceptual Design Preliminary Design Cycle Requirements Failure Space Final Design Cycle Requirements Failure Space Design Design Trades/Analysis Trades/Analysis updates Implementation V&V Planning V&V Development V&V Execution Thu Oct

8 Sample Task Descrip'on 8

9 B.TSD.03: Derive Preliminary FM Design and Map into failure space SE Function: Technical Solution Definition Phase: B Example Ar'facts and/or Template Safing design demonstrates how all systems/subsystems coordinate to produce safe end state Fault Coverage/Mi:ga:on List This is customizable for each mission but is should include the faulted func:on, the symptom, the mi:ga:on (or preven:on steps), and where the mi:ga:on is being done. Item # faulted function cause h/w item (if applicable) fault injection method mitigation identified where? allocated to whom? response timeliness: comments 1 clock runs slow wonky oscillator avionics clock external oscillator detect somehow and swap clocks FFA onboard FP: local response quick, before it affects users 2 Fail to maintain attitude newbie specifies -Z instead of +Z n/a command incorrect vector offsun angle monitor calls safing to sunpoint fault tree onboard FP: system response medium, before attitude exceeds thermal rqmts 3 Fail to maintain attitude model error in attitude estimator n/a tweak code? extensive testing fault tree designers: prevent fault medium, before attitude exceeds thermal rqmts flight rule: Fail to command incorrect double check 4 maintain n/a bad fault tree parameter parameter attitude parameter values mission operators: prevent fault medium, before attitude exceeds thermal rqmts O Return to Derive Preliminary FM Design and Map into failure space 9

10 Guidebook Naviga'on 10

11 Purpose and Plan Product purpose Field-guide for engineer Manager s planning tool The Deep Space Robotic chapter of the FM Handbook Companion to the NASA Systems Engineering Handbook Plans Completion: Early CY 2015 Posted on NASA Engineering Network on Fault Management Community of Practice 11