Wrong forward kinematics? about xarm-python-sdk

[penglongxiang]

Hi @orrkrup, recently we have added kinematics calibration to our product, thus the actual kinematic parameters will be a little different from the nominal DH parameters we provide. The results from get_forward_kinematics() API and Studio have already taken the calibration into account.

If you need to extract the calibrated parameters, please download the following python script and run python3 gen_kinematics_params.py {robot_ip} {kinematics_suffix}, the suffix is an arbitrary string to distinguish between multiple arms. It will then generate a yaml file in user/ directory.

Inside the yaml file, there is the extracted calibrated parameters of your robot arm. Please note the form will not be DH any more, it is the 6DOF (x,y,z, roll pitch yaw) transformation relationship between adjacent joint coordinates, and the unit is in Meters and Radians. Please refer to our user manual for roll pitch yaw Euler angle definitions. If you apply serial matrix calculation based on this extracted parameters, the FK result should agree with that shown on Studio.