This slide presentation reviews the integrated Guidance, Navigation and Control (iGN&C) system in the design for the Orion spacecraft. Included in the review are the plans for the design and development of the external interfaces, the functional architecture, the iGN&C software, the development and validation process, and the key challenges that are involved in the development of the iGN&C syste

Chevray, Kay

NASA Technical Reports Server

https://ntrs.nasa.gov/search.jsp?R=20090036321 2019-08-30T08:08:48+00:00Z
Outline
♦ As Background:
• Project Orion Mission
• iGNC role in Orion Program
♦ Design and Development Plans:
• External Interfaces
• Functional Architecture
• GN&C Software Overview
• Development and Validation Process
• Key Challenges
Orion Integrated GN&C / K. Chevray	 Page 2
Injection Burn	 R
EO	 D
Launch
On	 AbortCLV	 (contingency) Precision landing in
US coastal waters
Deorbit Burn
Jettison
SM
Precision landing in
US coastal waters
Jettison
SM
Injection Burn
Launch
On
CLV Abort(contingency)
Project Orion Mission At-A-Glance
ISS Design Reference Mission
Altair/Crew on
Surface	 Trans-Earth
Injection BurnsUncrewed
Ref: Orion GN&C Subsystem Design Review
February 2009	
Lunar Design Reference Mission
Orion Integrated GN&C / K. Chevray 	 Page 3
Integrated GN&C(iGNC)Role within Oriong
♦ Orion GN&C team operates under Multiple Organizational Design
and Engineering (MODE) team agreement between NASA and prime
contractor, Lockheed-Martin (LM)
n MODE team arrangement allows NASA engineers to collaborate with the
prime contractor during design process
• Allows to leverage off of NASA’s experience with manned systems
• Allows greater insight into prime contractor’s design
• Each MODE team within the GN&C Subsystem Products Team (GNC SPT) is
co-led by a NASA lead and a LM lead
♦ As a NASA side lead, I have responsibilities on both sides
n As a System Manager, monitor design activities and evaluate the design
• 30 System Managers and 80 Subsystem Managers
n The roles are expected to diverge after CDR, as LM personnel concentrates
on test and verification while NASA personnel will focus on assessment of LM
data for vehicle acceptance
Orion Integrated GN&C / K. Chevray	 Page 4
iGNC Role within Orion (cont’d)
♦ iGNC is a MODE team that is responsible at the subsystem level for:
• Systems Engineering
• Inter-MODE team integration and external interfaces
• Requirements
• Flight software architecture including Phases, Segments, and Modes
• Fault Detection, Isolation, and Recovery (FDIR)
• Test and Verification
• Simulation development
♦ In addition, iGNC personnel participates in the following activities
with other organizations
• Constellation (level II) requirements coordination through Flight Performance
System Integration Group (FPSIG) – CARD and IRD requirements
• Coordination with the International Space Station (ISS) for Rendezvous,
Proximity Operations, and Docking (RPOD) related topics – Orion/ISS IRD
requirements, docking conditions
Orion Integrated GN&C / K. Chevray	 Page 5
MODE Team Responsibilities
♦ Integrated GN&C (iGNC):
n Requirements, verification, sim development, and technical integration
♦ Ascent Abort (AAMT):
n Handles GN&C for all ascent aborts including LAS and SM aborts
♦ Orbit (OMT):
n Handles navigation filter design and GN&C for on-orbit, transit, and RPOD
♦ Entry (EMT):
n Handles entry GN&C including CM burns, guided entry, and roll under mains
♦ Operability and Piloting (OPMT):
n Handles manual control, flight displays, and ops interfaces across mission
♦ Contingency Return (CRMT):
n Handles GN&C for BEC/MRC vehicle capabilities
♦ Navigation Systems (NavSys):
n Nav hardware design and system integration across all mission phases
Orion Integrated GN&C / K. Chevray	 Page 6
Aerosciences Thermal
• aero database • trajectories
Models &Sims Loads & Dynamics
• models from Osiris • dynamic environment
database • trajectories
Propulsion (PROP)
• thruster specifications
• thruster commanding
• thruster configuration
Guidance,
Navigation &
Control
(GNC)
Environmental
Control and Life
Support (ECLS)
• active thermal
control of VPU & IMU
• venting constraints
Crew Health and
Habitation
Accommodation
(CHHA)
• VNS & Docking
Camera stowage
External Interfaces
Avionics (AV)
• transfer commands and data to / from
sensors & effectors
• data for crew displays & other constellation
elements
• health / status, FDIR & test report data
• abort & contingency data
• phase, segment, activity & mode data
• crew and ground commands
• range, range rate & bearing
• command latency & resolution
• memory and processing resources
Landing and
Recovery Systems
(LRS)
• trigger conditions
notification
• vehicle control for
descent and landing
Electrical Power
(EPS)
• power
Thermal Protection 	 Mechanisms (MECH)	 Structures (STR)
Wiring (WIRE)	 System (TPS)	 • docking mechanism	 • sensor mounting
• power & signal 	
• thermal protection for	 constraints	 • windows for opticaldistribution	 Star Tracker	 sensors
Org Org Org Provides Org Provides
Driving Interface SEIT (Subsystem to Subsystem)	 Other Organizations Provides Receives & Receives & Receives
Ref: Orion GN&C Subsystem Design Review
Orion Integrated GN&C / K. Chevray 	 Page 7	 February 2009
Ref: Orion GN&C Subsystem Design Review
Orion Integrated GN&C / K. Chevray 	 Page 8	 February 2009
606E GN&C Subsystem Boundary DiagramY	 rY	 rag
Backup Flight System
GN&C Software
r---------------------------
1 Guidance/Targeting
------
i i
--------------------------
-------^
Guid Health Ascnt Entry
FTaMgmt TargGuid TargGuid Guid
CSCI = Computer SW Configuration Item
CSC = Computer SW Component
CSU = Computer SW Unit
"Domains”/CSCs
(CSU detail not shown here)
Ownership
Ascent Abort MODE Team
Orbit MODE Team
Entry MODE Team
Navigation Systems
Propulsion
Orion GN&C FSW Overview
z	 ^
Flight Computer/VMC
FCM (SCP)
DCM (SCP)
CCM
VMC = Vehicle Mgmt Computer
FCM = Flight Control Module
DCM = Display Control Module
CCM = Communications Control Module
SCP = Self Checking Pair (of processors)
"CSCIs“
(1 SRS per CSCI)
Rate Grou ps, Hz (ms)
40 (25 ms) - High
20 (50 ms) - Med-High
10 (100 ms) - Med
5 (200 ms) - Med-Low
1 (1000 ms) - Low
Note:
D&C HW/SW reuse requires data rates
in multiples of 20Hz (50 ms).
input
	 output
GNCP Partitions
Navigation
r--------------------------- ------
GNC Cmd Interface
---------------------------- -----^
Control/Propulsion
-------------------
Cntrl Health LAS- CM- SM-
i
	
Mgmt Cntrl Cntrl Cntrl
Mass PropSys Engine
Prop Cntrl Cntrl
----------------------------------
i
CSC	 CSC i
CSU CSU
CSU	 CSU ii
Nav Health Abs Rel Ephem
Mgmt Nav Nav Proc
Time/Space
(notional)
ARINC 653 Partitions
SKP	 IOP ANAV GNCP IOP CDH CMT ADL	 TM
Multiple rate groups can reside within the partition. 	 Ref: Orion GN&C FSW Overview
Orion Integrated GN&C / K. Chevray 	 Page 9
	 W. Tamblyn
!!:	 Development	 process and validationz	 ^	 p	 p
♦ GN&C MODE teams responsible for the development of GN&C
algorithms
n Guidance, navigation, control, executive, FDIR, parameters for display
♦ Algorithms documented in modeled based design tool
(Matlab/Simulink)
n FSW provides the executive architecture
• Architecture developed by GN&C FSW architecture working group, co-led by GN&C
and FSW
n GNC provides the detailed algorithms within the architecture (CSCI’s)
n Simulation capability to close the loop directly with the FSW algorithms during
the development phase
♦ Auto-coded version of the Matlab/Simulink becomes the flight
software at the CSCI level
♦ Flight software then will get tested and verified via various test
facilities
Orion Integrated GN&C / K. Chevray	 Page 10
Key Challenges
♦ Communication
• With the size of Orion Project and the GN&C team, maintaining an open
communication channels is difficult
• Need to find the right balance of enough participation to make correct decisions vs.
too many people attending too many meetings to get the “real” work done
♦ Horizontal vs. vertical integration
• GN&C team is organized by flight phase, which allows for easier integration inside
a given phase. iGNC is responsible for horizontal integration across various flight
phases, which requires matrixed support from flight phase teams.
♦ Requirements management
• Flow down from Level II (Constellation Program) and Level III (Orion Project)
through Crew Module and Service Module Specifications to GN&C Specifications
• Performance allocations at the vehicle level
• GN&C subsystem spec vs. flight software requirements
• How many requirements is too many?
♦ Test and verification
• Development vs. formal verification testing
• Testing at subsystem vs. system level
• Time required to complete the verification in test facilities
Orion Integrated GN&C / K. Chevray	 Page 11


Orion Integrated Guidance, Navigation, and Control [GN and C]

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server