Single Camera Pick and Place

## Single Camera Pick and Place

Captures an image after picking the workpiece and places it in the taught fixed position. (The robot arm's shooting position is fixed. When the picked workpiece is offset, the placement position of the workpiece remains unchanged.)

## Module Principle

The camera picks the object and moves to the bottom camera to take a picture. Because the position of the object picked each time is different, the object captured at the same shooting position will have deviations. The Single Camera Pick and Place module corrects the deviation of the object through the bottom camera shooting and calibration calculation, and correctly places the object into the fixture.

![](/media/202603/2026-03-12_170003_1629580.664313533286305.png)

Mechanical models are divided into XYR, XR, YR (with angle) and XY, X, Y (without angle) types. The calculation methods for the two types of picking are different. Picking with an angle requires the input calibration data to also be of the XYR, XR, YR type with an angle. Picking without an angle has no requirement for calibration.
For the compensation amount in a mechanical model with angle R, the compensated R will affect the XY values. (That is, if only R is compensated, the XY position where the robot arm picks the workpiece will not change, but the actual mechanical XY coordinates will change slightly to compensate for the rotation.)

#### Teaching
Teaching is the process where an operator or engineer teaches the system how to identify target objects, understand the scene, or execute specific visual tasks before or during the picking process.
The operation steps are: place a material on the picking plane, get its workpiece pixel point and workpiece pixel angle on the image, and record it by clicking **Learn**. **Teach Shooting Pose** is the bottom camera shooting position of the robot arm. **Teach Place Pose** is the pose coordinate when the mechanism places it into the fixture at the currently learned workpiece coordinates. Every time a new pick module is created, calibration changes, or the robot arm's teach shooting pose changes, teaching must be performed again.

![](/media/202603/2026-03-12_170018_6859700.234321915890487.png)

## Usage Scenarios

![](/media/202601/2026-01-16_093935_4796510.7652256065570148.png)
Example of the robot arm picking the workpiece and going to the bottom camera field of view:

![](/media/202601/2026-01-16_093958_1610850.9781819640916756.png)

![](/media/202601/2026-01-16_094008_0492090.28464900809767846.png)

As shown in the figure, at the same shooting position, because the position of the picked workpiece is different, the object has an offset, affecting the placement of the object into the fixture. Single Camera Pick and Place converts the offset captured by the bottom camera into the placement position compensation through calibration, thereby correctly placing it into the fixture.

## Usage Method

### Pre/Post-Sequence Modules

![](/media/202603/2026-03-12_170031_9565190.2918412708708106.png)
**Camera Image Acquisition**, **Optimized Feature Matching** to get the workpiece image point coordinates for single camera picking, **Calibration Reference** to introduce calibration for converting image point coordinates for single camera pick and place. (Note that when using a bottom camera, the X-axis needs to be mirrored)
First, complete the port connection and fill in the fixed bottom camera shooting position. Run once first to learn the input image point coordinates. Then manually move the mechanism to place the workpiece into the fixture, and record the placement coordinates into the **Teach Place Pose** of the Single Camera Pick and Place (can be introduced externally). Run subsequently to get the pick coordinate output.

## Parameter Configuration Description

Mechanical Model (Eye-to-Hand):
【XYR】 Mechanical structure XY axes can translate and rotate.
【XY】 Mechanical structure XY axes can translate, but cannot rotate or do not need to 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.
【X (Y Separated)】 Mechanical structure only has X-axis translation, Y-axis structure is separated.
【Y (X Separated)】 Mechanical structure only has Y-axis translation, X-axis structure is separated.
【Mechanical Travel】 Allowed travel range of the robot arm.
【Compensation Amount】 Mechanical coordinates, compensated in the mechanical coordinate system. When clicking subscribe, the compensation amount can be introduced via the port.
【Reference Image】 The image taken after picking the workpiece.
##### Teaching Settings

![](/media/202603/2026-03-12_170054_4215500.8049173998158042.png)

【Workpiece Coordinates】 Image coordinates, the image pose corresponding to the camera shooting during teaching. Can be manually entered based on the port's workpiece pixel point/angle, or click Learn to introduce the port's workpiece pixel point/angle. When clicking Learn, the current workpiece pixel coordinates are required to be the image coordinates during teaching. And it only needs to be learned once. It only needs to be learned again when the teach shooting pose changes or the teaching material changes.
【Teach Shooting Pose】 Mechanical coordinates, the mechanical end coordinates when the camera can capture the teaching material. Subsequent picked materials will all be photographed at this teach shooting pose position.
【Teach Place Pose】 Mechanical coordinates, the mechanical end coordinates when fixing the placement after picking the teaching material. Click Subscribe to introduce this coordinate via the port.

## Output Description
The output is the actual placement position of the robot arm.
## Precautions

1. When using a bottom camera, the X-axis needs to be mirrored because the coordinate system of the mechanism captured by the bottom camera is opposite to the actual one.
2. When using a pick type with an angle, the input calibration data is also required to be of the XYR, XR, YR type with an angle.
3. Every time a new pick module is created, calibration changes, or the robot arm's pick position changes, teaching must be performed again.
4. Learning the teach image point requires running once first to get the input before learning.
   
## Error Troubleshooting
1. When picking is inaccurate, prioritize reteaching and testing again.
2. Pay attention to whether the feature matching module acquires an accurate image.
3. If still unable to pick accurately, test the accuracy of the calibration (the calibration module introduces testing).
4. If there is a large offset angle leading to inaccurate XY, it may be caused by an error in the calculation of the calibration rotation center. Try to recalibrate, modify the calibration method, and improve the calculation of the rotation center (add calibration verification or use the long radius calibration module).
5. If the center is accurate but there is XY deviation around the periphery, consider image distortion (use the Image Distortion Correction module), or calibration scale calculation error (use the Calibration Correction module).

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Click here to jump to the corresponding Chinese manual page: [Single Camera Pick and Place](/doc/144)