Seatbelt device of vehicle for determining whether a user wears a seatbelt correctly or erroneously

A seat belt apparatus of a vehicle, the seat belt apparatus comprising:

• a seat belt coupled to a seat and comprising a webbing comprising a detectable material or a paint in at least one pattern;
• a vision sensor configured to generate an image by capturing a field of view region comprising the seat;
• and
• a monitoring system configured to:
• detect the detectable material or the pattern coated with the at least one paint in the image;
• detect a pattern matching a specific pattern in the image;
• determine whether a user wears the seat belt correctly or erroneously wears the seat belt based on the detected detectable material or the pattern coated with the at least one paint;
• derive at least two regions of interest (ROI) from the image;
• and
• calculate a withdrawn webbing length by:
• storing a pattern detected at an uppermost end of a non-wearing ROI among the derived at least two ROIs;
• and
• comparing a number of the patterns detected at the uppermost end of a wearing ROI among the derived at least two ROIs with a number of the patterns detected at the uppermost end of the non-wearing ROI after the seat belt is worn;
• wherein the uppermost end of the non-wearing ROI and the uppermost end of the wearing ROI are common predetermined areas.