System for detecting thickness of a coating autonomously applied to a structure

A method comprising:

• during a first coating period:
• navigating a spray nozzle across a first region of a structure;
• and
• applying a coating to the first region of the structure via the spray nozzle;
• deactivating an optical emitter arranged adjacent the spray nozzle at a first time;
• accessing a baseline image of the first region captured by an optical sensor at the first time;
• oat approximately the first time:
• activating the optical emitter to illuminate the first region of the structure behind the spray nozzle;
• and
• accessing a first image of the first region captured by an optical sensor;
• generating a normalized image of the first region of the structure, representing fluorescent intensity of the coating corrected for incident ambient light, by subtracting the baseline image from the first image;
• calculating an average color intensity of pixels within the normalized image;
• converting the average color intensity of pixels into average a first coating thickness of the coating applied to the first region of the structure;
• in response to the first coating thickness exceeding a maximum coating thickness, storing a first flag for inspection of a paint sag within the first region of the structure;
• during a second coating period:
• navigating the spray nozzle across a second region of a structure;
• applying the coating to the second region of the structure via the spray nozzle;
• illuminating the coating applied to the second region of the structure;
• detecting an intensity of light at the second region of the structure;
• converting the intensity of light into a second coating thickness of the coating applied to the second region of the structure;
• and
• in response to the second coating thickness falling below a minimum thickness, storing a second flag for recoating the second region of the structure.