Robot system and coordinate conversion method

A coordinate conversion method for converting a detected position detected by a sensor system into position coordinates in a robot coordinate system recognized by a robot controller, the method comprising:

• detecting position coordinates of a first detection object in a state in which two or more detection objects are positioned in a detection area of the sensor system and the two or more detection objects other than the first detection object are intentionally hidden by a predetermined method;
• detecting position coordinates of a second detection object in a state in which the two or more detection objects are positioned in the detection area and the two or more detection objects other than the second detection object are intentionally hidden by the predetermined method;
• creating a conversion matrix which conducts coordinate conversion, in a plane including an X-axis and a Y-axis, on a position obtained by the sensor system based on the position coordinates of the first detection object, the position coordinates of the second detection object, and two sets of position coordinates in an X-axis direction and a Y-axis direction in the robot coordinate system, the two sets of position coordinates in the robot coordinate system corresponding to the first detection object and the second detection object, respectively;
• and
• converting the detected position detected by the sensor system by using the conversion matrix.

A robot system comprising:

• a sensor system;
• a conveyor;
• a robot configured to conduct a task on two or more parts or products transferred by the conveyor;
• and
• a robot controller which controls the robot, wherein
• the sensor system is configured to obtain an image of the two or more parts or products transferred by the conveyor and configured to perform image processing on the image for pass/fail inspection of the two or more parts or products;
• the sensor system is capable of detecting two or more sets of position coordinates of the two or more parts or products based on the image to which the image processing is performed;
• the robot controller is configured to conduct matrix creation processing to create a conversion matrix which conducts coordinate conversion, in a plane including an X-axis and a Y-axis, on a position obtained by the sensor system, based on the two or more sets of position coordinates of the two or more parts or products obtained by the sensor system and two or more sets of position coordinates in an X-axis direction and a Y-axis direction in the robot coordinate system, the two or more sets of position coordinates in the robot coordinate system corresponding to the two or more parts or products;
• the robot controller receives a second set of position coordinates obtained by the sensor system, the second set of position coordinates identifying a position different from the position coordinates obtained by the sensor system in a moving direction of the conveyor;
• the robot controller conducts coordinate conversion on the second set of position coordinates and at least one of the two sets of position coordinates by using the conversion matrix;
• and
• the robot controller performs determination processing to determine whether the coordinate system of the sensor system is a right-hand coordinate system or a left-hand coordinate system based on determination of whether or not a difference in position in the x-axis direction between the position coordinates and the second set of position coordinates, which are subjected to the coordinate conversion, is equal to or smaller than a reference value.

A coordinate conversion method for converting a detected position detected by a sensor system into position coordinates in a robot coordinate system recognized by a robot controller, the method comprising:

• obtaining, by the sensor system, an image of two or more parts or products transferred by a conveyor;
• performing, by the sensor system, image processing on the image for pass/fail inspection of the two or more parts or products;
• detecting, by the sensor system, two or more sets of position coordinates of the two or more parts or products based on the image to which the image processing is performed;
• creating a conversion matrix which conducts coordinate conversion, in a plane including an X-axis and a Y-axis, on a position obtained by the sensor system based on the two or more sets of position coordinates of the two or more parts or products obtained by the sensor system and two or more sets of position coordinates in an X-axis direction and a Y-axis direction in the robot coordinate system, the two or more sets of position coordinates in the robot coordinate system corresponding to the two or more parts or products;
• converting the detailed position detected by the sensor system using the conversion matrix;
• receiving, by the robot controller, a second set of position coordinates obtained by the sensor system, the second set of position coordinates identifying a position different from the position coordinates obtained by the sensor system in a moving direction of the conveyor;
• conducting coordinate conversion on a second set of position coordinates and at least one of the two sets of position coordinates by using the conversion matrix, the second set of position coordinates obtained by the sensor system and identifying a position different from the position coordinates obtained by the sensor system in a moving direction of the conveyor;
• and
• determining whether the coordinate system of the sensor system is a right-hand coordinate system or a left-hand coordinate system based on determination of whether or not a difference in position in the x-axis direction between the position coordinates and the second set of position coordinates, which are subjected to the coordinate conversion, is equal to or smaller than a reference value.