Robot Calibration Using Optical Target Sensing
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Solution Overview
Problem
Conventional robot calibration methods require shutting down manufacturing equipment, which is time-consuming and expensive, especially in industries like semiconductor fabrication, where maintaining absolute positioning is crucial but disruptive to ongoing processes.
Innovation Solution
A sensory calibrating device that senses start and end points of a target using sensors, calculates the target's center, determines the offset between the target center and a robot blade, and calibrates the robot position without altering the processing chamber's conditions, allowing calibration with the lid closed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional calibration methods are used, then robot positioning accuracy is improved, but manufacturing downtime increases
Solution Approach 1:
The calibration target is pre-installed on the processing chamber before production operations begin. This allows the robot to perform self-calibration during idle moments or between batches without requiring equipment shutdown, thus maintaining positioning accuracy while minimizing manufacturing downtime.
Solution Approach 2:
The robot performs self-calibration by autonomously detecting the pre-installed target using its own sensors and computing its position relative to the target. This eliminates the need for manual calibration operations, allowing the system to calibrate itself during minimal disruption to production workflows.
2Measurement precision
If manual calibration operations are performed, then robot positioning accuracy is improved, but operational complexity increases
Solution Approach 1:
The robot autonomously performs calibration by detecting the pre-installed target and computing its position relative to the target using its own sensors and processing capabilities. This self-service approach eliminates manual alignment operations and reduces calibration complexity while maintaining high positioning accuracy.
Solution Approach 2:
Manual mechanical alignment operations are replaced with an automated optical/electronic detection system. The robot uses sensors to detect the calibration target and computationally determines its position, substituting complex manual mechanical alignment with simpler automated detection and calculation processes.
3Measurement precision
If processing chamber conditions are altered for calibration, then robot positioning accuracy is improved, but process disruption increases
Solution Approach 1:
The calibration target is pre-installed on the processing chamber before production operations begin. This allows calibration to be performed without altering processing chamber conditions such as pressure, temperature, or gas composition, thereby maintaining process continuity while achieving accurate robot positioning.
Solution Approach 2:
The calibration process is designed to occur without interrupting or altering the processing chamber environment. The robot can perform calibration while the chamber maintains its operational conditions, ensuring continuous productive action without the need to shut down or reconfigure processing parameters.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces maintenance time and manufacturing downtime by enabling precise robot calibration without altering processing conditions, thus minimizing disruptions and costs.
Implementation Method 1
sensing start points and end points of a target using sensors located on a calibrating device
Data Source
AI summary
Described herein is a method and apparatus for performing calibrations on robotic components. In one embodiment, a method for performing robotic calibrations includes moving the calibrating device across a target (e.g., a wafer chuck). Next, the method includes measuring distances between light spots from the sensors and a perimeter of the target using the sensors located on the calibrating device. Next, the method includes determining a displacement of the calibrating device relative to a center of the target. Then, the method includes determining a rotation angle of the calibrating device relative to a system of coordinates of the target. Next, the method includes calibrating a robot position of the robot based on the displacement and rotation angle of the calibrating device with respect to the target.