| 摘要 |
<p>PROBLEM TO BE SOLVED: To detect a side ditch that constitutes a recess, a level difference between a walkway and roadway, etc., using an inexpensive distance sensor that does not have a scanning mechanism.SOLUTION: Provided is a road surface monitoring device 2 that radiates, in a road surface direction also, part of an ultrasonic wave emitted into the air from an ultrasonic sensor 11. An obstacle detection unit 30 compares the form of a received wave that is a reflected wave returned after being reflected at a surface with the form of a past received wave of the road surface to detect a missing part, and determines the presence of a recess in the road surface by detection of the missing part. On the basis of this determination result, a warning unit 3 gives a warning to a driver, and a control unit 4 controls an electric cart 1 so as to avoid falling off or tumbling down into the recess.</p> |
