Robot Tool Offset Calibration Using Force Feedback Contact
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Solution Overview
Problem
Current robotic systems face challenges in accurately determining tool offsets, which are essential for precise control, especially when the geometry of the attached tool is unknown or changes over time due to wear and tear, requiring manual and potentially inaccurate measurement.
Innovation Solution
An automated process where the robot identifies a reference object, contacts it with the tool to collect position data, and iteratively determines tool offset data using force feedback sensors and encoded joint angles, allowing for precise determination of tool offsets in multiple dimensions, including X, Y, Z, and angular offsets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual measurement methods are used to determine tool offsets, then the process is simple to implement, but measurement precision and accuracy deteriorate due to user error
Solution Approach 1:
The robotic system performs self-calibration by automatically determining tool offsets through iterative contact with a reference object and using force feedback sensors to detect contact points, eliminating the need for manual measurement by operators
Solution Approach 2:
The patent replaces manual mechanical measurement methods with an automated system combining robotic movement, force feedback sensing, and computational algorithms to determine tool offsets with higher precision
2Measurement precision
If automated tool offset determination is implemented, then measurement precision improves, but device complexity increases due to additional sensors and control systems
Solution Approach 1:
The system uses force feedback sensors to detect when the tool contacts the reference object, providing real-time feedback to the control system to automatically adjust and determine accurate tool offsets without requiring complex external measurement equipment
Solution Approach 2:
The robotic system performs multiple functions including tool offset determination, contact detection, and position calculation using integrated sensors and control algorithms, reducing the need for separate dedicated measurement devices
3Adaptability or versatility
If tool geometry changes over time due to wear, then adaptability is needed, but manual remeasurement increases time loss
Solution Approach 1:
The system performs quick iterative contact tests with the reference object to detect tool wear and update offset values, using minimal repeated measurements rather than full remeasurement procedures to maintain adaptability while minimizing time loss
Data Source
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AI summary
Example systems and methods are disclosed for determining tool offset data for a tool attached to a robot at an attachment point. The method may include controlling the robot to contact a reference object with the tool. The reference object may be a rigid object with a known location. A force feedback sensor of the robot may indicate when the tool has contacted the reference object. Once contact is made, data indicating robot position during tool contact may be received. Additionally, the robot may temporarily stop movement of the tool to prevent damage to the tool or the reference object. Next, tool offset data may be determined based on the position of the reference object relative to the robot and the received robot position data. The tool offset data, may describe the distance between at least one point on the tool and the attachment point.