The following tutorial is a tutorial for hand-eye calibration of Realman RM65-B. After communicating with the after-sales service of the robotic arm, hand-eye calibration is carried out based on the relevant documents provided. The summary process is as follows.
1. Preparation
1.1 Hardware:
(1) Prepare a chessboard calibration plate. If high accuracy is required, you can buy it online, or you can print it yourself and place it on a flat surface;
(Attached is a link to the chessboard generation web page to calibrate the chessboard grid generation . You can customize the size of the chessboard. Click Save below to save the pdf)
(2) Riemann RM65-B robotic arm
(3) Depth camera, I use L515 camera
(4) Industrial computer or computer. I use an industrial computer with ubuntu18.04 system. This tutorial also supports windows.
1.2 Software:
(1) python3.8 and above
(2) numpy1.24.4
（3）scipy1.10.1
（4）pyrealsense2 2.53.1.4
(Just download the latest version for 2, 3 and 4)
After preparing the hardware and software environment, fix the camera at the end of the robotic arm and connect the camera to the industrial computer. Place the calibration plate on a fixed plane, which can be placed on the ground, to ensure that the position of the calibration plate does not move during the calibration process, and no errors occur. After the camera can reach the visible range, start the robotic arm and industrial computer after arranging it.
2. Start calibration
2.1 Data collection
According to the provided file, use pycharm to open it, go to the data_collection_d435_win folder, and modify the cam0_path variable in the main.py file to the target folder path for saving the calibration plate images. Here I named it my_images.
Modify the startup parameters of the L515 camera. If it is a D4 series camera, no modification is required:
Go to the provided API directory, unzip the file, and copy
U盘:\1、RM-65\（2）API\C\linux\linux_x86_base_release_v4.1.3\libRM_Base.sofile to
\D435标定教程\data_collection_d435_win\file directory, used to replace the RM_Base.dll file. The dll file is only used in Windows systems.
Enter data_collection_d435_win/robotic_arm.py,
Make the following changes:
Run data_collection_d435_win/main.py,
When the color picture taken by the camera appears, press and hold the teaching button at the end of the robotic arm and save it every time you move the robotic arm. Ensure that the calibration plate appears clearly and completely within the field of view and the robotic arm base and calibration plate remain motionless. Move a small amount at a time. The robot arm, and each joint is active during the entire image collection process, manually stops running after saving 50 images.
Go to the my_images folder and you will find the saved pictures and poses.txt file. The poses.txt file contains the poses of each robotic arm.
2.2 Obtain the internal reference matrix
Enter data_collection_d435_win/main.py,
Modify the data source:
Modify the number of corners and spacing of the checkerboard:
Run the main.py file and output the rotation matrix and translation vector :
