Drone-Based Non-Destructive Inspection of Industrial Sites: A Review and Case Studies

Reviews drone-based non-destructive inspection of industrial sites, centred on active and passive thermography, plus visual inspection, ultrasonic probing with a wall-sticking drone, gas sensing and radiation detection, and presents case studies. Cases cover thermal image stitching, reflection detection, video stabilisation and active thermography of aerospace composites. Stated challenges include vibration, false positives from sun and reflections, the stand-off versus resolution trade-off, propeller wash disturbing surface temperature, and payload limits.

Key findings

• Thermal readings weaken with stand-off distance, and propeller downwash can disturb surface temperature
• Sun angle, shadows and reflections (including of the drone itself) cause thermal false positives
• Heavy cooled cameras and flash lamps exceed typical drone payloads
• Aircraft wing-box test: data too noisy for PCT/PPT processing to give accurate results

Limitations

• Case-study results mostly qualitative
• Contact ultrasonic thickness and eddy current barely covered
• Several cases are aerospace rather than plant assets