Hand-Eye Automatic Calibration with the CRX Plugin
This section introduces the process of calibrating the camera extrinsic parameters using the CRX plugin.
Preparation before Calibration
Make preparation before calibration according to the camera mounting method.
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If the camera is mounted in the Eye to Hand method, see Preparation before Calibration in Automatic Calibration in the Eye-to-Hand Setup.
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If the camera is mounted in the Eye in Hand method, see Preparation before Calibration in Automatic Calibration in the Eye-in-Hand Setup.
Pre-calibration Configuration
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Open Mech-Vision, and click the Camera Calibration button in the toolbar. The Configuration before Calibration window will be prompted.
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Confirm that the checks are performed, click I’ve finished all checks, and then click Next.
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In the Select how to calibrate window, select the New calibration radio button, and then click the Next button.
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In the Select calibration task window, select Hand-eye calibration for listed robot from the drop-down list box, click the Select robot model button to select the robot model used by the project, and then click the Next button.
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In the Select camera setup window, select the camera mounting method in this project, and then click the Next button.
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In the Calibration method and robot control window, select Automatic and Standard Interface, and then click the Calibrate button to go to the Calibration window.
Calibration Procedure
Conduct calibration according to the camera mounting method.
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If the camera is mounted in the Eye to Hand method, see Calibration Procedure in Automatic Calibration in the Eye-to-Hand Setup.
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If the camera is mounted in the Eye in Hand method, see Calibration Procedure in Automatic Calibration in the Eye-in-Hand Setup.
Precautions
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When you proceed to the third calibration step (connecting the robot) and you click Start interface service button in the Connect the robot window, the button will change to Waiting for the robot to connect.... If the interface service is already started, you do not need to perform this operation.
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When the button displays Waiting for the robot to connect..., perform the following steps on the robot side. Then, continue the calibration in the software.
1. Create a Calibration Program
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Create a new robot program. The program name in this example is MM_AUTO_CALI. Select Programming, and drag the commands in the ALL tab to the program line in the following order: Mech-System SocketInit → User Frame Select → Tool Frame Select → J → Mech-Eye Calibration.
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Press Mech-System SocketInit on the program line to view the details of the command. Set the IP Address of IPC to the host address and set the Port of IPC to the port number configured in Mech-Vision.
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Press User Frame Select, and set the User Frame Number to 0.
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Press Tool Frame Select, and set the Tool Frame Number to 1.
2. Teach Calibration Start Point
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Press J motion.
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Manually move the robot to the start point of the calibration. The start point for automatic calibration is at the center of the lowest layer in the calibration path.
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Select Pos.Reg, and enter the number of the pose register. The register 100 is used in this example. Then press the
icon to display the Cart./Joint button.
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Press Cart./Joint to switch to Cartesian reference frame.
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Press the Touch Up button, and select OK in the dialog box to save the start point of calibration.
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Press Mech-Eye Calibration, and configure the parameters as shown in the figure below.
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Motion Type: Specify the motion type during the automatic calibration process.
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Data Type: The pose type the robot sends.
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Wait Time: The time the robot waits to avoid shaking after it moves to the calibration point.
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PR Index: Set the register number where the calibration start point is stored.
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3. Run Calibration Program
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Switch to the Automatic mode, and press Play in the lower left corner. Reduce the velocity, and then press Run.
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When, in the Configuration window in Mech-Vision, the current status changes to connected and the button Waiting for the robot to connect changes to Disconnect robot, click Next. Next, proceed to the fourth step of the calibration process (i.e. setting the movement path).
Change the Extrinsic Parameter File
If the camera’s extrinsic parameter file has been used by a Mech-Vision project, you need to change the extrinsic parameter file used by the Mech-Vision project to a new one after you finish the hand-eye calibration.
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Select the Capture Images from Camera Step.
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In the Step Parameters panel, click
of the Calibration Parameter Group parameter, and select the newly calibrated extrinsic parameter file.
Calibration-Related Status Codes
During automatic calibration via Standard Interface communication, the vision system returns data together with the status code to the robot. Status codes, which are categorized into error codes and normal status codes, indicate the command execution status. Calibration related status codes are listed in the tables below.