Determining condition of conveyor belt by calculating apparent velocities from captured images of conveyor belt

Patent metadata

Field	Value
Publication number	US-12008746-B2
Application number	US-201817296792-A
Country	US
Kind code	B2
Filing date	Dec 6, 2018
Priority date	Dec 6, 2018
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

An inspection device includes an acquisition unit that acquires a plurality of images, captured from a given height, of an inspection object controlled to move at a constant velocity, a comparison unit that compares movements of the inspection object in the images on the basis of the plurality of images, and a determination unit that determines the condition of the inspection object on the basis of a comparison result.

First claim

What is claimed is:

1. A system comprising:
a conveyor belt that is configured to move at a constant velocity;
a camera installed at a constant installation height above the conveyor belt and in a downwards-oriented direction towards the conveyor belt, the camera configured to capture a plurality of first images of the conveyor belt as the conveyor belt moves;
at least one memory configured to store instructions; and
at least one processor configured to execute instructions to:
acquire, from the plurality of first images, a plurality of second images at successive acquisition clock times;
on a basis of the plurality of second images, compare movement of the conveyor belt in the second images; and
determine a condition of the conveyor belt on a basis of a comparison result, by:
for each of a plurality of pairs of the second images, determining a number of pixels that a region has moved from one image of the pair to the other image of the pair;
for each pair, determining an apparent moving amount according to the number of pixels that the region has moved;
for each pair, calculating an apparent velocity by dividing the determined apparent moving amount by a difference between the acquisition clock times of the pair; and
comparing the plurality of calculated apparent velocities for the plurality of pairs.

2. The system according to claim 1 , wherein the at least one processor determines the condition of the conveyor belt on a basis of the plurality of calculated apparent velocities and a predetermined threshold.

3. The system according to claim 2 , wherein the at least one processor determines the condition of the conveyor belt on a basis of a difference between a highest apparent velocity and a lowest apparent velocity among the plurality of apparent velocities, and the predetermined threshold.

4. The system according to claim 1 , wherein
the at least one processor determines the condition of the conveyor belt on a basis of a degree of separation of the plurality of the apparent velocities from a logical value corresponding to when the conveyor belt is not deteriorated.

5. The system according to claim 1 , wherein the at least one processor calculates the apparent velocity in each of a plurality of divided regions obtained by dividing a capturing region of each second image.

6. An inspection method comprising:
installing a camera at a constant installation height above a conveyor belt and in a downwards-oriented direction towards the conveyor belt, the camera configured to capture a plurality of first images of the conveyor belt as the conveyor belt moves;
acquiring, by a processor, from the plurality of first images, a plurality of second images at successive acquisition clock times;
on a basis of the plurality of second images, comparing, by the processor, movement of the conveyor belt in the second images; and
determining, by the processor, a condition of the conveyor belt on a basis of a comparison result, by:
for each of a plurality of pairs of the second images, determining a number of pixels that a region has moved from one image of the pair to the other image of the pair;
for each pair, determining an apparent moving amount according to the number of pixels that the region has moved;
for each pair, calculating an apparent velocity by dividing the determined apparent moving amount by a difference between the acquisition clock times of the pair; and
comparing the plurality of calculated apparent velocities for the plurality of pairs.

7. A non-transitory computer-readable medium storing a program comprising instructions executable by a processor to:
acquire, from a plurality of first images of a conveyor belt captured as the conveyor belt moves and by a camera installed at a constant installation height above the conveyor belt and in a downwards-oriented direction towards the conveyor belt, a plurality of second images at successive acquisition clock times;
on a basis of the plurality of second images, compare movement of the conveyor belt in the second images; and
determine a condition of the conveyor belt on a basis of a comparison result, by:
for each of a plurality of pairs of the second images, determining a number of pixels that a region has moved from one image of the pair to the other image of the pair;
for each pair, determining an apparent moving amount according to the number of pixels that the region has moved;
for each pair, calculating an apparent velocity by dividing the determined apparent moving amount by a difference between the acquisition clock times of the pair; and
comparing the plurality of calculated apparent velocities for the plurality of pairs.

Assignees

• Nec Corp

Inventors

• Takada Jun

Classifications

• G06T2207/30108

  Industrial image inspection · CPC title

• B65G2203/042

  Sensors · CPC title

• B65G2203/041

  Camera · CPC title

• B65G2203/0291

  Speed of the load carrier · CPC title

• B65G2203/0275

  Damage on the load carrier · CPC title