Position detection device for robot, robotic system, and position detection method for robot

1. A position detection device for a robot comprising:

an imaging section configured to take an image of an object located in an imaging area during movement of the robot, the object being held by an end effector of the robot;

an image processor configured to calculate a centroid of the object based on the image taken by the imaging section;

an acquisition section configured to obtain a drive amount of a drive source of the robot so as to calculate an end effector calculated position;

a controller configured to correct an end effector location of the end effector; and

a sensor including:

a light projector that outputs a light; and

a light receiver that receives the light, wherein

the light traverses the imaging area of the imaging section so that the sensor is configured to generate a common trigger signal when the object is detected by the sensor based on the light, wherein

the imaging section starts to take the image of the object when the imaging section receives the common trigger signal,

the acquisition section starts to obtain the drive amount when the acquisition section receives the common trigger signal, and

an object location of the object is detected based on the image and the drive amount, and

the controller corrects the end effector location based on the centroid of the object and the end effector calculated position.

2. The position detection device for a robot according to claim 1 , wherein

the sensor configured to detect whether one of the robot and a work held by the robot as a detection object reaches a predetermined position, and then output the common trigger signal to the imaging section and the acquisition section in response to the detection object reaching the predetermined position.

3. The position detection device for a robot according to claim 2 , wherein

the detection object corresponds to the object of the imaging section, and

the sensor detects whether the detection object reaches the imaging area of the imaging section.

4. The position detection device for a robot according to claim 1 , wherein

the object corresponds to a work held by the robot, and

the end effector configured to grip the work is optically shielded by the work with respect to the imaging section in the imaging area of the imaging section.

5. The position detection device for a robot according to claim 1 , further comprising:

a calculation section configured to calculate the object location of the object from the image taken by the imaging section; and

a storage section configured to store the calculated location of the object and the drive amount so as to correspond to each other, wherein

the storage section stores a target position of the object and the drive amount of the drive source so as to correspond to each other, and

the position detection device further comprises:

a correction section configured to correct a correspondence relationship between the target position and the drive amount for reaching the target position based on a correspondence relationship between the calculated location and the drive amount stored in the storage section.

6. A robotic system comprising:

a robot configured to convey a work; and

the position detection device for the robot according to claim 1 , the position detection device being configured to detect one of a location of the robot and a location of the work conveyed by the robot.

7. A robotic system comprising:

a robot configured to convey a work; and

the position detection device for the robot according to claim 2 , the position detection device being configured to detect one of a location of the robot and a location of the work conveyed by the robot.

8. A robotic system comprising:

a robot adapted to convey a work; and

the position detection device for the robot according to claim 3 , the position detection device being configured to detect one of a location of the robot and a location of the work conveyed by the robot.

9. A robotic system comprising:

a robot adapted to convey a work; and

the position detection device for the robot according to claim 4 , the position detection device being adapted to detect one of a location of the robot and a location of the work conveyed by the robot.

10. A robotic system comprising:

a robot adapted to convey a work; and

the position detection device for the robot according to claim 5 , the position detection device being configured to detect one of a location of the robot and a location of the work conveyed by the robot.

11. A position detection method for a robot comprising:

taking an image of an object located in an imaging area during movement of the robot, the object being held by an end effector of the robot;

calculating a centroid of the object based on the image;

obtaining a drive amount of a drive source of the robot so as to calculate an end effector calculated position;

correcting an end effector location of the end effector; and

generating a common trigger signal when a sensor detects the object, wherein

the sensor includes:

a light projector that outputs a light; and

a light receiver that receives the light, wherein

the light traverses the imaging area so that the sensor detects the object based on the light,

the taking and the obtaining start in response to receiving the common trigger signal so that an object location of the object is detected based on the image and the drive amount, and

the end effector location is corrected based on the centroid of the object and the end effector calculated position.