US-12623841-B2 - Robot and article dimension obtainment method

US12623841B2US 12623841 B2US12623841 B2US 12623841B2US-12623841-B2

Abstract

A robot includes a holder, a puller, a sensor, and a dimension obtainer. The holder holds an article placed on a supporter. The puller pulls the holder to a front side. The sensor detects that the article being pulled out ceased being on the supporter. The dimension obtainer obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the sensor detects that the article ceased being on the supporter.

Inventors

Hideshi Yamane
Eiji YOSHIKUWA
Toshiyuki Tsujimori

Assignees

KAWASAKI JUKOGYO KABUSHIKI KAISHA

Dates

Publication Date: 20260512
Application Date: 20211124
Priority Date: 20201124

Claims (9)

1 . A robot, comprising: a holder that holds an article placed on a supporter; a puller that pulls the holder to a front side; a limit switch that detects that the article being pulled out ceased being on the supporter; a dimension obtainer that obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the limit switch detects that the article ceased being on the supporter, a robot body; and an end effector that is attached to a distal end of the robot body, wherein the limit switch is arranged at the end effector.
2 . The robot according to claim 1 , wherein a pullout of the article starts with a face of the article on the front side and a face of the supporter on the front side belonging to a same plane.
3 . The robot according to claim 1 , comprising a controller that controls the robot body and the end effector, wherein the end effector includes a receiver that carries the article that ceased being on the supporter, and wherein the controller controls the puller so that the article is pulled out while a top surface of the receiver being lower than a bottom edge of a face of the article on the front side.
4 . The robot according to claim 3 , wherein the limit switch is arranged at the receiver.
5 . The robot according to claim 1 , wherein the holder is arranged at the end effector that is attached to a distal end of the robot body, and wherein the puller includes a pulling conveyor that is arranged at the end effector and slides the holder.
6 . The robot according to claim 5 , wherein, if the limit switch does not detect that the article ceased being on the supporter even after the pulling conveyor moved the holder to a limit of slide movement, the robot body pulls out the article further together with the end effector until the limit switch detects it.
7 . A robot, comprising: a holder that holds an article placed on a supporter; a puller that pulls the holder to a front side; a strain sensor that detects that the article being pulled out ceased being on the supporter; a dimension obtainer that obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the strain sensor detects that the article ceased being on the supporter; a robot body; and an end effector that is attached to a distal end of the robot body, wherein the strain sensor is arranged at the end effector.
8 . A robot, comprising: a holder that holds an article placed on a supporter; a puller that pulls the holder to a front side; a sensor that detects that the article being pulled out ceased being on the supporter; a dimension obtainer that obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the sensor detects that the article ceased being on the supporter; a robot body; and an end effector that is attached to a distal end of the robot body, wherein the sensor is a force sensor that is arranged at a distal end of the robot body.
9 . A robot, comprising: a holder that holds an article placed on a supporter; a puller that pulls the holder to a front side; a sensor that detects that the article being pulled out ceased being on the supporter; and a dimension obtainer that obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the sensor detects that the article ceased being on the supporter, wherein the holder is arranged at an end effector that is attached to a distal end of a robot body, and wherein the puller includes a pulling conveyor that is arranged at the end effector and slides the holder.

Description

TECHNICAL FIELD The present disclosure relates to obtainment of a dimension of an article by a robot. BACKGROUND ART Robots have been conventionally used to pick and transfer an article placed in a predetermined location. PTL 1 discloses a robot of this type. The robotic picking system of PTL 1 picks a box from an unstructured pallet. This robotic picking system locates the box using a computer vision and/or one or more “exploratory picks” to determine the size and location of the box in the pallet. The exploratory pick is a motion of the robot and an attached gripper lifting the outermost box from its corner by a small amount to separate it from the top layer. The system computes a difference between two images that are took before and after the separation to determine the size of the picked box and its position in the top layer. PRIOR-ART DOCUMENTS Patent Documents PTL 1: Japanese Patent Application Publication No. 2019-509559. SUMMARY OF THE INVENTION Problems to be Solved by the Invention With the configuration of above-mentioned PTL 1, the size of the box may not be obtained by the computer vision if the box is covered by another object. Therefore, a configuration that enables the obtainment of the size by a means different from the conventional method has been desired. The present disclosure is made in view of the situation described above, and its purpose is to obtain a dimension of an article along the pullout direction, regardless of whether or not the surface of the article is covered by another object. Means for Solving the Problems The problem to be solved by the present disclosure is as described above. The means to solve this problem and the effects thereof will be described below. A first aspect of the present disclosure provides a robot with a configuration described below. That is, the robot includes a holder, a puller, a sensor, and a dimension obtainer. The holder holds an article placed on a supporter. The puller pulls the holder to a front side. The sensor detects that the article being pulled out ceased being on the supporter. The dimension obtainer obtains a dimension of the article along a pullout direction based on a distance that the article is pulled for from when the puller starts to pull out the article until when the sensor detects that the article ceased being on the supporter. A second aspect of the present disclosure provides an article dimension obtainment method described as follows. That is, the article dimension obtainment method includes a pulling out process, a detecting process, and an obtaining process. In the pulling out process, an article placed on a supporter is pulled out to a front by at least one of a robot body or an end effector. In the detecting process, a sensor detects that the article being pulled out ceased being on the supporter. In the obtaining process, a dimension of the article along a pullout direction is obtained based on a distance that the article is pulled for from when the pulling out process starts until when the sensor detects that the article ceased being on the supporter. This allows the dimension of the article along the pullout direction to be obtained based on when the supporter ceases supporting the article in the process of pulling out the article. Effects of the Invention According to the present disclosure, the dimension of the article along the pullout direction can be obtained regardless of whether or not the article is covered by another object. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an overall configuration of a robot according to one embodiment of the present disclosure. FIG. 2 is a perspective view showing a robot hand. FIG. 3 is a perspective view showing a robot hand viewed from a robot body. FIG. 4 is a functional block diagram showing an electrical configuration of a robot. FIG. 5 is a drawing illustrating an operation of a robot obtaining a depth dimension of an article. FIG. 6 is a side view illustrating another operation of a robot obtaining a depth dimension of an article. FIG. 7 is a flowchart illustrating a process performed by a robot. EMBODIMENT FOR CARRYING OUT THE INVENTION The disclosed embodiments will be described below with reference to the drawings. FIG. 1 is a perspective view showing an overall configuration of a robot 1 according to one embodiment of the present disclosure. FIG. 2 is a perspective view showing a robot hand 20. FIG. 3 is a perspective view showing the robot hand 20 viewed from the robot body 10. The devanning robot (robot) 1 shown in FIG. 1 is used to take out an article 5, which is arranged three-dimensionally in a container 6, from the container 6 and transfer it to a predetermined position. The predetermined position may be, for example, but not limited to, on a conveyor, which is not shown in the drawings. In the present embodiment, the article 5 is a box. Specifically, it is a rectangular cardboard box. The box may contain an object or it may also be e