Embedded Vehicle Version Identification Tracking and Compatibility Checking

1
Embedded Vehicle Version Identification Tracking
and Compatibility Checking

• Edgar Dalrymple
• Computer Engineer, US Army AMCOM, Software
  Engineering Directorate
• Aviation Missile RDTE Center

• Bruce Bardell
• Chief Systems Engineer, A3 Bradley Fighting
  Vehicles
• United Defense LP, Ground Systems Div.

2
A Reprogrammable Weapon Platform

• The preponderance of software-based Line
  Replaceable Units (LRUs) in a complex digital
  architecture enables cost-effective software
  loading by the Unit level maintainer
• Platform software updates are made for a number
  of reasons
• Improve existing behavior
• Add new functions
• Adapt to hardware changes
• Critical aspects are controlled by software
• Operational and Safety functions
• User interfaces
• Performance characteristics
• LRU interfaces

Close control of all fielded platform LRU
hardware and software is impractical
3
Achieving Planned Improvements and Compatibility
with New Hardware

• Planned Improvements have two levels of system
  impact
• Changes isolated within LRUs
• Changes that affect LRU to LRU interfaces
• Introduction of new hardware must consider
• Changes isolated within LRUs
• Degree of downward compatibility must be
  understood
• Establishment of a sunset date on legacy
  hardware

4
Version Reporting Hierarchy - LRUs, Sub-LRUs, and
SRUs Within the System
5
VVID and Sub-VVID Notional Example

• LRU Versions contained in a few similar System
  VVIDs
• The VVID number that is displayed when a match is
  discovered may in reality contain LRUs of
  different versions, but the platforms behavior
  at a crew level is identical
• Every possible combination of LRU hardware and
  software versions is accounted for as a unique
  sub-VVID

VVID and sub-VVID
Version changes that drive functional impacts
Other version differences
6
Weapon Platform System Computer Collects and
Assesses Data

• The potential for incompatible LRUs to be
  introduced onto weapon platform does exist
• Battle Damage Assessment and Repair
• Expedient Maintenance
• Version data is made available to the system
  computer
• Data must be present during a predetermined
  period at system power-up
• Data must meet the formatting constraints defined
  in the platform interface control drawings (ICDs)
• The system computer contains the database needed
  to assess Vehicle-level compatibility
• All known fielded LRU hardware and software
  versions are included
• All safety-certified combinations of those LRUs
  are tabulated
• Known undesirable combinations are also tabulated

7
Weapon Platform System Computer Advises the Crew

• The system computer reports the exact or nearest
  Vehicle Version Identification (VVID)
• If all LRU hardware and software exactly matches
  a safety-certified combination, the platform
  meets a valid VVID and the VVID number is
  displayed on the start-up screen exact versions
  of all LRUs are contained on a set of screens
  available via the menu tree
• If not all LRU hardware and software exactly
  match a safety-certified combination, the system
  computer determines the nearest match, but
  displays Invalid VVID expected versions of the
  nearest match of all LRUs are contained on a set
  of screens

8
Example VVID Screen(1st of 4 Bradley A3 Screens)
Ordinal sequence doesnt match numeric sequence
Comparison Criteria of reported and expected
versions Ordinal Values
Comparison Results . Pass, f Fail First
position hardware Second position software
9
Weapon Platform System Computer Takes Action

• When the system computer doesnt detect an exact
  VVID match, additional actions may occur via the
  Compatibility Checking function
• The crew is always advised to proceed with
  caution
• For version mismatches that have been
  predetermined as undesirable, the degree of
  safety concern dictates any further action the
  system may take
• Display advisories
• Disable functions
• Log faults
• Power off LRUs
• Inhibit transition to Combat State

10
Support Equipment also uses the VVID

• System Software Loader
• Used for two purposes
• Bring the weapon platform up to a recently
  released VVID
• Bring the weapon platform to a valid VVID at the
  conclusion of a maintenance action
• Operates by assessing available platform hardware
  to determine how to create a valid VVID from its
  file of software
• Weapon platform type
• Set of LRU hardware versions
• Direct Support Benchtop Test Equipment
• Used to identify faulty module in an LRU, if the
  LRU is incapable of full self-diagnosis
• Used to facilitate post-repair verification
• Brings LRU to recent or current version that is
  compatible with its hardware content, so System
  Software can do its job

11
Platform Startup
Turn On Power
Display VVID Unknown, expected and actual
versions, and Proceed with Caution
Power-on all default loads
Run System Controller self-test and establish
bus communications
Collect sub-LRU and SRU version data
Predefined Mismatches?
No
Compatibility Checking
Collect hardware and software versions across
system
Report version data upon request
Yes
Provide predefined alerts, function inhibits,
power shutdowns, fault reports
Vehicle Version Identification
Determine System VVID
Inhibit Combat ?
Valid VVID?
Yes
No
No
Display VVID number, expected and actual versions
Enter Combat State
Yes
End
12
Benefits to Bradley A3

• Unambiguous definition of all tested and approved
  fieldable platform configurations
• Concise means of referring to the current and
  historical platform-level hardware and software
  suites
• Benefit to defect-tracking metrics
• Easier targeting of problem resolution
• Becomes part of engineer, Field Service,
  Customer, and User/Tester jargon
• Personnel and equipment protection in the event
  that an unapproved configuration must be utilized
• Assistance to Government-furnished Equipment
  providers to clarify the required versions of
  their equipment