On-Bridge Deflection Measurement (OBDM™)

General Description

OBDM™ (On-Bridge Deflection Measurement)

Vertical deflection is a critical metric for the evaluation of a bridge’s load carrying capacity and, more specifically, its rigidity following a hazardous event. Smart OBDM is a simple on-bridge deflection measurement method that uses distinctively marked targets and a commercial camera.



  • No traffic detours or disruption during bridge structure evaluation
  • No scaffolding and no cabling
  • Easy to set baseline for successive inspection purpose: easy to process visual image, and easy to archive and reevaluate data
  • Long-term reliability

Digital Image Analysis

New Picture 17 On Bridge Deflection Measurement (OBDM™)



Bridge Side View

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Loading Test Verification

Load Test Verification On Bridge Deflection Measurement (OBDM™)


Deflections compared to Conventional Transducer Practice

Comparison On Bridge Deflection Measurement (OBDM™)





















Technical Description

Drone Sensing Technology Suave (Smart Unmanned Aerial Vehicle Evaluation) has been developed by integrating:

  1. Advance High-Definition Camera Capturing Technology:  60 ft. away from surface of interest, a crack width of 100 microns can be  measured
  2. Digital Image Processing Technology
  3. Advanced GPS navigation system: the drone will follow a preprogrammed flight plan which targets those areas of a bridge suspected of having experienced deterioration
  4. The control system includes a built-in collision avoidance capability



Items Properties
Pay load 1.5 kg
Allowable wind speed 10m/s
Distance & Altitude 1 -1.5km & Max 300m
Definition 4952 x 3056
Focal 55mm
Distance 20m
Coverage 8.51m x 5.67m
Resolution 1.85mm/pix

Crack Analysis


Crack Analysis 1024x382 On Bridge Deflection Measurement (OBDM™)


Crack width severity is displayed as four distinct colors

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Structural Condition Monitoring