Recess detection device, transport device, and recess detecting method

A transport device comprising:

• a recess detection device that detects a recess in a flat portion intersecting with a visual field plane of a three-dimensional sensor, based on distance image information of a detection target including the flat portion;
• the recess detection device including:
• a reference value decision processor that extracts, from the distance image information, a plurality of pieces of reference information respectively corresponding to a plurality of reference regions located at different positions within a detection range with a distance from the three-dimensional sensor being within a predetermined range, and determines a reference value based on the plurality of pieces of reference information;
• and
• a presence identification processor that extracts, from the distance image information, pieces of comparison information respectively corresponding to a plurality of comparison regions within the detection range, derives comparison values based on the respective pieces of comparison information, and indicates a presence of a recess when a difference between the reference value and the comparison value exceeds a predetermined threshold;
• a vehicle, to which the recess detection device is attached, and which moves autonomously;
• and
• a holder that is attached to the vehicle and holds a placement target placed on the detection target.

A recess detecting method for detecting a recess in a flat portion intersecting with a visual field plane of a three-dimensional sensor, based on distance image information of a detection target including the flat portion, the recess detecting method comprising:

• causing a reference value decision processor to extract, from the distance image information, a plurality of pieces of reference information respectively corresponding to a plurality of reference regions located at different positions within a detection range in the flat portion with a distance from the three-dimensional sensor being within a predetermined range;
• causing the reference value decision processor to determine a reference value based on the plurality of pieces of reference information;
• causing a presence identification processor to extract, from the distance image information, pieces of comparison information respectively corresponding to a plurality of comparison regions within the detection range in the flat portion;
• causing the presence identification processor to derive comparison values based on the respective pieces of comparison information;
• and
• causing the presence identification processor to indicate a presence of a recess when a difference between the reference value and the comparison value exceeds a predetermined threshold.