Automating RCS Measurements for High-Speed Production Line In-Process Verification

Key Factors for Adding Production Line IPV

RCS Measurements

“No Experience Necessary”

• Make RCS measurements using Production Line Technicians
• Answers are the same using a 20-year RCS engineer and a Tech that started last week

High Reliability

• The production grind is relentless
• No time for troubleshooting or repairs

Fast

• Testing every part needs to take WAY less time than the repair time at the existing failure rate

Why Use In-Process Verification (IPV)?

• Find problems early
• There is less invested in the part
  • Repair is easier
  • Scrap is easier to tolerate (time and money)
• See small changes in RCS before they are a problem
  • Minor process changes (new person?) or machine wear
• Components are known good before applied to aircraft

Delta Sigma Company can do your Chamber Planning, including

• Chamber Design
• Antenna Design
• Shroud Design
• Radar Design
• Pylon, Column, & Rotator Designs
• Elevator & Tilt Mechanism & Pit Cover Designs
• Integrated System Control Software
• Data Processing Software

Delta Sigma designs and builds Automated RCS Measurement Systems

• 1 button push for:
  • Chamber Door opens
  • Automatic Target loading
  • Chamber Door Closes
  • Automatic collection of all frequencies/polarizations/LDA’s/AZ angles
  • Automatic data processing of all above
  • Automatic compare to standard for pass/fail for all above
  • Automatic display to operator of pass/fail
  • Automatic Target unloading
• User does not affect the test process!

Production Line Measurements Must Reduce User Skill Requirements

• User skill still needed (probably) to
  • attach item-under-test to test fixture
• If test result = fail
  • Assess if failure is due to part or part/fixture interface
  • Repair interface if necessary
• Engineering skill still needed if result = fail
  • But this expertise is not needed in the test chamber
  • Hopefully, rarely needed

Automatic Target Support Selection

• Some parts are mounted into a test fixture for RCS testing
• Some parts sit atop a foam column for RCS testing
• System auto-selects correct one based on part being tested

Automatic Target Loading

• User pushes cart with loaded test fixture to chamber
  • Cart is on air bearings
  • 700 pounds – less than 10 pounds of force to push
• Cart is guided to proper position
  • Cart/pit-covers interface forces proper alignment
  • Sensors detect in-position
• Pylon raises while operator holds a wireless “live-man switch”
• Target is engaged and locked automatically
• Operator removes empty cart
• Pylon raises to full height and tilts to test position
• Rotator moves to starting AZ and EL position

Automatic Data Collection

• Once the Pylon and Rotator are in position the radar starts data collection
• Frequency range can include any bands desired
• The number of steps in a chirp can be 2 to 65k
• After all waveforms at a given EL angle are complete, the system moves to the next EL angle
• Repeat until all EL angles are complete

Automatic Data Processing/Compare to Standard

• Data processing is real time
• A 2D ISAR image is produced a second or so after the last chirp is collected at every angle of interest
• Boxes are placed in the key positions on the image to obtain “box scores”
• Box scores are compared to the same box in the Standards data
• Pass/fail is determined for numerous criteria (boxes)

Automatic Pass/Fail

• If any box fails, the part fails
• A massive amount of data is available to engineers for RCS diagnostics
  • Determine the repair process or scrap
• If all boxes pass, the part passes and moves to the next step of the build-process

Automatic Target Unload

• User pushes the empty cart into chamber
• Cart is guided to proper position
• The pylon will have already lowered to just above cart height
• Pylon lowers while operator holds a wireless “live-man switch”

Target is unlocked and disengaged automatically

• Operator removes loaded cart

Assorted Pylons