Robot Calibration
Robot calibration uses a camera to measure the pose of a calibration sphere at different robot poses and calculates the robot’s zero positions and link lengths based on the measurements. These parameters are used to compensate for the robot’s structural parameters, thereby improving its absolute accuracy. Robot absolute accuracy is an important factor affecting robot picking accuracy.
To access this feature, go to in the Mech-Vision menu bar.
This chapter guides you through selecting and completing a robot calibration workflow.
Scope and Limitations
Before using robot calibration, make sure that the robot and camera meet the following requirements:
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The camera is fixed outside the robot, in an Eye to Hand scenario. Eye in Hand scenarios are not supported.
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Only six-axis robots with spherical wrists and UR robots are supported. For supported models, refer to the robot model library in the software.
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Only PRO S-GL and NANO ULTRA-GL cameras are supported. The tool recommends the camera model, number of cameras, and installation area based on the robot model and calibration task. The actual installation position must also be determined based on the available space and the robot’s reach.
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The robot must support master-control communication. During calibration, Mech-Vision must be able to read the robot status, and the robot must be able to receive joint position commands.
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Only Zero position calibration and Zero position and link length calibration are supported. Other robot parameters cannot be calibrated.
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This feature calibrates robot zero position and link length errors; it cannot resolve robot repeatability issues. If the robot cannot consistently reach the same position, troubleshoot the robot itself, transmission system, load, installation, and control status first.
Selecting a Robot Calibration Workflow
Robot calibration workflows are classified by robot reach and Calibration task. After you select a robot model, the tool determines the robot’s reach and recommends the number and model of cameras.
Pre-calibration Checks
Before robot calibration, complete the required checks. Please refer to Pre-calibration Checks for details about the checks and requirements.
Performing Robot Calibration
Select a robot calibration workflow based on the robot’s reach and calibration task, and refer to the help documents in the following table to complete the calibration.
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The robot reach is based on the parameters of the selected model in the software’s robot model library. Robots with a reach of 1.8 m or greater are classified as large-reach robots; those with a reach of less than 1.8 m are classified as small-reach robots. The tool automatically determines the reach category based on the selected robot model. |
| Calibration Workflow | Robot Reach | Calibration Task | Recommended Camera | Help Document |
|---|---|---|---|---|
Zero Position Calibration for Large-Reach Robots |
Large reach |
Zero position calibration |
1 PRO S-GL camera |
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Zero Position and Link Length Calibration for Large-Reach Robots |
Large reach |
Zero position and link length calibration |
2 PRO S-GL cameras |
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Zero Position Calibration for Small-Reach Robots |
Small reach |
Zero position calibration |
1 NANO ULTRA-GL camera |
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Zero Position and Link Length Calibration for Small-Reach Robots |
Small reach |
Zero position and link length calibration |
1 NANO ULTRA-GL camera |