N-Point Calibration

## N-Point Calibration
Provides generation of calibration image point groups and mechanical point groups. Generate a new calibration.

## Module Principle

![](/media/202603/2026-03-12_153116_6357330.4014308209619414.png)

Physical Point Array Image Point Array: Image points and mechanical points used for calibration form an array input, which needs to be in one-to-one correspondence.

The image points can be obtained directly by taking photos, but the mechanical points need to be calculated. That is, the mechanical points can be calculated on another calibrated plane, and then the mechanical points on this plane can be calculated through mechanical handling.
## Usage Scenarios
[Some modules have their exclusive usage scenarios, please list them in detail in this section]

## Usage Method

### Predecessor/Successor Modules

#### Departure Camera Photographing:
1. Departure camera acquires image, circle extraction gets departure image point A1.
2. Calibration reference, calibration conversion converts image point A1 to departure mechanical point a1.
3. Mechanical handling, move departure mechanical point a1 to the mechanical point a2 on the plane where calibration needs to be calculated.
4. Repeat multiple times (calibration generation requires more than four times), and record the obtained mechanical points a2, b2, c2, d2...

![](/media/202603/2026-03-12_153310_4988720.29704527204738007.png)

#### Arrival Camera Photographing

5. Arrival camera acquires image, circle extraction gets arrival image point A2.
6. Repeat multiple times (calibration generation requires more than four times), and obtain A2, B2, C2, D2...
7. The fourth time, combine the recorded image points A2, B2, C2, D2... and mechanical points a2, b2, c2, d2... into an array to generate N-point calibration.

![](/media/202603/2026-03-12_153324_7664430.1383741149852461.png)
## Parameter Configuration Description
【Calibration Group】 Select the corresponding coordinate system group, and the calibration data will be recorded in the calibration file under the coordinate system group. The coordinate system group must be set in the coordinate system calibration in the global data management.
【Calibration File】 Select the calibration file under the corresponding coordinate system group, and the calibration data will be recorded in the file. (The calibration file must be set in the coordinate system calibration in the global data management. First add the 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)<br>

![](/media/202603/2026-03-12_153207_4429120.9459910230221449.png)

Physical Point Array Image Point Array: Image points and mechanical points used for calibration form an array input, which needs to be in one-to-one correspondence.
## Precautions
1. Note that the calibration plane and the plane when using calibration are of the same height, and trays, calibration object thickness, etc. need to be considered.
2. During mechanical handling, when placing objects, object sliding may occur.
3. Points used for generating calibration should be evenly distributed in various positions of the image, especially in the case of large field of view calibration.
4. The points of the departure camera and the arrival camera must correspond one-to-one, and be the same point on the calibration object.
5. The lower camera needs x-axis mirroring when used.
6. The plane used for calibration needs to be the same height as the plane when using calibration.
## Problem Solving
Build the following flow to test the xy direction accuracy of calibration. Move the matching object 1-10mm, observe whether the calibration conversion result changes correspondingly to test the accuracy.
![](/media/202603/2026-03-12_152203_6181840.08111837465297045.png)
During alignment or grasping, when the offset angle increases, causing the error of xy to increase correspondingly, it means that the rotation center of the calibration is calculated incorrectly. You can solve the problem by increasing the angle movement of calibration (more than 30 degrees). Or by checking calibration verification, using long radius calibration, etc.

[【Attachment】N-Point Calibration Example Project.rar](/media/attachment/2026/03/N%E7%82%B9%E6%A0%87%E5%AE%9A%E7%A4%BA%E4%BE%8B%E5%B7%A5%E7%A8%8B.rar)

---

Click here to jump to the corresponding Chinese manual page: [N-Point Calibration](/doc/129)