Calibration method for laser processing robot

A robot system comprising:

• a laser processing robot including a base that is fixed on an installation surface, a movable portion that is movable with respect to the base, and a laser processing tool that is mounted at a distal end of the movable portion and that has a distance measuring function by scanning a measurement laser beam, the laser processing robot having a robot coordinate system;
• a controller that controls the laser processing robot;
• and
• a measurement jig that includes a measurement target site having a prescribed shape and that is fixed to the base,
• wherein the controller is configured to:
• store a position and orientation of the measurement target site in the robot coordinate system as a first position and orientation that are determined by fixing the measurement jig to the base;
• place the laser processing tool, by operating the movable portion, at a position where the measurement laser beam can be scanned with respect to the measurement target site and store coordinates of a tool center point of the laser processing tool in the robot coordinate system;
• measure distances between respective portions of the measurement target site and the tool center point by scanning the measurement laser beam at the measurement target site;
• calculate a position and orientation of the measurement target site in the robot coordinate system as a second position and orientation on the basis of the measured distances and a position of the tool center point in the robot coordinate system, the position of the tool center point being determined by the position at which the laser processing tool is placed;
• calculate a coordinate transformation function for converting the calculated second position and orientation into the stored first position and orientation;
• and
• correct the stored coordinates by using the calculated coordinate transformation function.

A laser processing robot comprising:

• a base fixed to an installation surface, a movable portion that is movable with respect to the base, and a laser processing tool that is mounted at a distal end of the movable portion and that has a distance measuring laser configured to scan a measurement laser beam, the laser processing robot having a robot coordinate system;
• a controller that controls the laser processing robot;
• and
• a measurement jig that includes a measurement target site having a prescribed shape and that is fixed to the base,
• wherein the controller is configured to:
• store a position and orientation of the measurement target site in the robot coordinate system as a first position and orientation that are determined by fixing the measurement jig to the base;
• place the laser processing tool, by operating the movable portion, at a position where the measurement laser beam can be scanned with respect to the measurement target site, and store coordinates of a tool center point of the laser processing tool in the robot coordinate system;
• measure distances between respective portions of the measurement target site and the tool center point by scanning the measurement laser beam with the distance measuring laser at the measurement target site;
• calculate a position and orientation of the measurement target site in the robot coordinate system as a second position and orientation on the basis of the measured distances and a position of the tool center point in the robot coordinate system, the position of the tool center point being determined by the position at which the laser processing tool is placed;
• calculate a coordinate transformation function for converting the calculated second position and orientation into the stored first position and orientation;
• and
• correct the stored coordinates by using the calculated coordinate transformation function.