CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a new U.S. Patent Application that claims benefit of Japanese Patent Application No. 2018-052484, filed Mar. 20, 2018, the disclosure of this application is being incorporated herein by reference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an article takeout apparatus and an article takeout method using a sensor and a robot.

2. Description of the Related Art

There has been known a system in which the respective positions and postures of a plurality of articles arranged in a working area defined by a pallet or container are measured by using a sensor such as a camera, and the articles are taken out by using a robot on the basis of the measurement results (e.g., see JP 2013-257182 A, JP 2003-010155 A, JP 2001-300878 A, JP 2008-087074 A, and JP 2017-042859 A).

In many article takeout apparatuses, one sensor is installed and configured to include the entire working area in the measurement range thereof (a field of vision), and in some cases, the working area is larger than the measurement range of the sensor, depending on a size of the working area or specifications of the sensor. In this case, only the installation of one sensor at a specific position fails to measure the entire working area. Thus, a method of covering the entirety of the working area is conceivable by mounting a sensor on a movable section such as a robot arm, etc., and conducting measurements multiple times while changing the position of the sensor.

However, when a plurality of articles are lopsidedly arranged in the working area, in some cases, it is inefficient to conduct measurements multiple times (at multiple positions). For example, in a device in which the entirety of a working area can be measured by conducting measurements with a sensor at multiple positions that are different from each other, when settings are made in which measurements are conducted again at all the positions every time one article is taken out, the measurements are meaningless at positions except for the position at which the article having been taken out is measured, and a time required for taking out the articles is extended.

In addition, in a case where settings are made wherein measurements are sequentially conducted at multiple positions in accordance with predetermined order and when an article to be taken out is detected and taken out, in some cases, it is meaningless to conduct the measurement since the measurement at the first position in such order is certainly conducted after the article is taken out. Thus, in the article takeout apparatus in which a working area is larger than the measurement range of a sensor, it is desirable to reduce the time of unnecessary measurements to a minimum.

SUMMARY OF THE INVENTION

One aspect of the present disclosure is an article takeout apparatus comprising: a sensor having a measurement range that is smaller than a working area in which a plurality of articles are arranged, and configured to be movable relative to the working area; a position/posture detector configured to detect a position/posture of the article on a basis of a measurement result of the measurement area that is a part of the working area with the sensor; a robot configured to take out the plurality of articles arranged in the measurement area on a basis of a detection result of the position/posture detector; a data storage configured to store evaluation data to evaluate a plurality of sensor measurement positions corresponding to respective positions at which the sensor measures a plurality of the measurement areas; a data update section configured to update the evaluation data after the measurement area is measured by the sensor and after the article is taken out by the robot; an evaluation value calculator configured to calculate a comprehensive evaluation value to evaluate a measurement state of an entirety of the working area on a basis of the updated evaluation data; and a sensor position selector configured to select a next sensor measurement position of the sensor from among the plurality of sensor measurement positions on a basis of the comprehensive evaluation value.

Another aspect of the present disclosure is an article takeout method using a sensor having a measurement range that is smaller than a working area in which a plurality of articles are arranged and configured to be movable relative to the working area, a position/posture detector configured to detect a position/posture of the article on a basis of a measurement result of a measurement area that is a part of the working area with the sensor, and a robot configured to take out the plurality of articles arranged in the measurement area on a basis of a detection result of the position/posture detector, the article takeout method comprising: storing evaluation data to evaluate a plurality of sensor measurement positions corresponding to respective positions at which the sensor measures a plurality of the measurement areas; updating the evaluation data after the measurement area is measured by the sensor and after the article is taken out by the robot; calculating a comprehensive evaluation value to evaluate a measurement state of an entirety of the working area on a basis of the updated evaluation data; and selecting a next sensor measurement position of the sensor from among the plurality of sensor measurement positions on a basis of the comprehensive evaluation value.

