Method and system for determining a workplace loading location in a CNC machine with a robotic arm

A method of determining a loading location of a workpiece relative to a holding fixture, comprising:

• activating, by a controller, a robot to grip the workpiece;
• enabling, by the controller, a free-drive mode of operation of the robot to permit an operator to move the workpiece to a starting location adjacent to a center of the holding fixture;
• causing, by the controller, the robot to automatically move in a first direction until a sensor coupled to the robot senses contact at a first position of contact between the workpiece and a first surface of the holding fixture;
• storing the first position of contact in a memory for use in computing a three-dimensional center point of the holding fixture;
• causing, by the controller, the robot to automatically move in a second direction until the sensor senses contact at a second position of contact between the workpiece and a second surface of the holding fixture;
• storing the second position of contact in the memory for use in computing the three-dimensional center point of the holding fixture;
• causing, by the controller, the robot to automatically move in a third direction until the sensor senses contact at a third position of contact between the workpiece and a third surface of the holding fixture;
• storing the third position of contact in the memory for use in computing the three-dimensional center point of the holding fixture;
• and
• computing, using the first position of contact, the second position of contact and the third position of contact, the three-dimensional center point of the holding fixture representing the loading location of the workpiece wherein the workpiece is positioned between the first, second and third positions of contact not in contact with the holding fixture.

A non-transitory, computer-readable medium storing instructions that, when executed by a controller, cause the controller to:

• activate a robot to grip a workpiece;
• enable a free-drive mode of operation of the robot to permit an operator to move the workpiece to a starting location adjacent to a center of a holding fixture;
• cause the robot to automatically move in a first direction until a sensor coupled to the robot senses contact at a first position of contact between the workpiece and a first surface of the holding fixture;
• store the first position of contact in a memory for use in computing a three-dimensional center point of the holding fixture;
• cause the robot to automatically move in a second direction until the sensor senses contact at a second position of contact between the workpiece and a second surface of the holding fixture;
• store the second position of contact in the memory for use in computing the three-dimensional center point of the holding fixture;
• cause the robot to automatically move in a third direction until the sensor senses contact at a third position of contact between the workpiece and a third surface of the holding fixture;
• and
• store the third position of contact in the memory for use in computing the three-dimensional center point of the holding fixture;
• and
• compute, using the first position of contact, the second position of contact and the third position of contact, the three-dimensional center point of the holding fixture representing a loading location of the workpiece wherein the workpiece is positioned between the first, second and third positions of contact not in contact with the holding fixture.