Fanuc Robotics North America, Inc.

Fanuc America Corporation

Fanuc Robotics America Corporation

Frank Garza

Brad Niederquell

Hadi A Akeel

H Dean McGee

Jason Tsai

Eric C Lee

A method and an apparatus detects pressure changes at servo gun tips of a robotic welding system having a servo gun with a movable tip and an opposed fixed tip configured to weld a part. The method and apparatus observe a tip deflection value and convert the value to a current pressure value using a pressure estimator. The current pressure value is compared to a benchmark pressure value to detect any difference.

Sensorless pressure change detection for servo gun

A method for controlling a welding robot having a servo gun with a movable tip and a fixed tip includes the steps of separately contacting a surface of a part with the movable tip to measure a base test point and an at least two additional test points displaced from the base test point. Two non-collinear vectors are calculated from the at least two additional test points. A normal vector is calculated from the two non-collinear vectors. An angle between the original servo gun orientation and the normal vector is determined. An orientation of the servo gun may be corrected, for example, if the angle is within user specified tolerances.

Robotic weld gun orientation normalization

A servo spot welding control system and method to efficiently weld a pair of workpieces together. The system includes a robot movable about the workpieces, a weld gun, servomotors, a transformer, and a controller. The weld gun is mounted on the robot and includes at least two pairs of electrodes. Each pair of electrodes includes a stationary electrode and a moveable electrode. The servomotors are operatively connected to the movable electrodes. The controller actuates the robot to move the robot into position. The controller also actuates the servomotors to clamp the workpieces and to selectively sequence electric current from the transformer to form multiple spot welds on the workpieces.

Servo spot welding control system and method of welding workpieces

A robot calibration system for calibrating a robot and a method of determining a position of the robot to calibrate the robot are disclosed. The system includes an electrical ground defining a return for an electrical circuit. The robot, which is electrically connected to the ground, includes an arm having a tool surface operating within a robot workspace. The system also includes an electrical supply and a detection device. The electrical supply defines a source for the circuit and provides a charge and a reference voltage to the system. The detection device communicates with the electrical supply to detect variations in either the charge, the reference voltage, or both. The system further includes a calibration object. The calibration object is electrically insulated from the ground and is electrically connected to the electrical supply. The calibration object receives the charge and the reference voltage from the electrical supply to determine the position of the robot relative to the calibration object when the tool surface moves toward the calibration object to electrically interact with the calibration object.

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Rochester Hills, MI, United States of America

Frank Garza