Long Radius Calibration (Manual)

## Long Radius Calibration (Manual)

Calculates the correspondence between the image coordinate system and the mechanical coordinate system, and generates a calibration file.

## Module Principle
By manually inputting the movement coordinates and inputting the image coordinates corresponding to the robot arm movement, the calibration relationship between the image pixel coordinates and the real-world coordinates is established and saved in the global variables.
The mechanical point and image point data are acquired externally (image points are usually obtained by acquiring feature points through Optimized Feature Matching).
Calibration only has XYR, XR, YR types with angles.
## Usage Method

### Pre/Post-Sequence Modules
Camera image acquisition, Optimized Feature Matching to acquire image point data, Thread Variable Writing to mechanical point array, run multiple times to generate calibration. The output of Camera Calibration is the mechanical point that needs to be reached next time.

![](/media/202603/2026-03-12_152402_5940970.8274020829560176.png)
## Parameter Configuration Description
【Mechanical Parameters】 Set the coordinates of mechanical movement, and obtain image coordinates through input images. 
Note: In calibration mode, the first picture taken is not included in the calculation; in simulation mode, the first photo will be used as the first point of the image points.
【Calibration Group】 Select the corresponding coordinate system group, and the calibration data will be recorded in the calibration file under this coordinate system group. The coordinate system group must be set in the Coordinate System Calibration in Global Data Management.
【Calibration File】 Select the calibration file under the corresponding coordinate system group, and the calibration data will be recorded in this file. (The calibration file must be set in the Coordinate System Calibration in Global Data Management. First add a coordinate system group, then drag the camera and robot to the window under the corresponding coordinate system group, select the connection line to connect the two icons, and the calibration file can be generated) 
【Save Image】 Save the reference image.
Mechanical Model:
【XYR】 Mechanical structure XY axes can translate and rotate. 
【XR (Y Separated)】 Mechanical structure only has X-axis translation and can rotate, Y-axis structure is separated. 
【YR (X Separated)】 Mechanical structure only has Y-axis translation and can rotate, X-axis structure is separated. 
Photographing Method: 
【Eye-to-Hand】 The camera is installed in a fixed position and does not shift or rotate with the machine. 
【Eye-in-Hand】 The camera is fixedly installed on the mechanical rotation axis and shifts and rotates with the machine. 
#### Mechanical Parameters 
【Mechanical Rotation Radius】 The physical distance from the rotation center to the feature matching point. Just input an approximate value to improve calculation speed. 
【Coordinate System Type】 Determine the coordinate system type of the robot arm. 
【Feature Point Angle】 Input the approximate angle of the feature point on the robot arm. Just input an approximate value to improve calculation speed. 
【Error】 The maximum error threshold between calibration data and calculation data on the mechanical axis. 
【Run Count】 Total number of calibration runs, minimum is 6. Calculate and generate calibration after running the set number of times. Movement requires changes in all xyr directions.

![](/media/202603/2026-03-11_084236_6084280.8509147515134922.png)
## Output Description

![](/media/202603/2026-03-12_152424_5157740.0293165648376712.png)
The total run result outputs true after the calibration is successful, otherwise false.
The single run result outputs the run result of each photographing movement.
When calibration generation fails, both the total run result and the single output are false.
## Precautions
1. When using a bottom camera, X-axis mirroring is required.
2. The height of the plane for calibration needs to be the same as the height during use, otherwise there will be errors.
3. In normal mode (calibration mode), the first image of camera calibration is not included in the calculation, and the camera needs to take one more photo to complete the calibration.
4. Movement requires changes in all xyr directions.
## Problem Solving
Build the following flow to test the accuracy of the calibration in xy directions. Move the matching object 1-10mm, observe whether the calibration conversion result changes correspondingly to test the accuracy.

![](/media/202603/2026-03-12_152446_4029360.012328659552584442.png)
During alignment or picking, when the offset angle increases, causing the xy error to increase correspondingly, it is a calculation error of the calibration rotation center. You can solve the problem by increasing the calibration angle movement (more than 30 degrees). Or by increasing the number of rotations.

[【Attachment】Long Radius Calibration (Manual) Example Project.rar](/media/attachment/2026/03/%E9%95%BF%E5%8D%8A%E5%BE%84%E6%A0%87%E5%AE%9A%E6%89%8B%E5%8A%A8%E7%A4%BA%E4%BE%8B%E5%B7%A5%E7%A8%8B.rar)

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Click here to jump to the corresponding Chinese manual page: [Long Radius Calibration (Manual)](/doc/127)