ur10_inverse_dynamics_solver

Contents

This dynamics solver for the real UR10 robot is based on a model identified at current level by the following paper:

V. Petrone, E. Ferrentino and P. Chiacchio, “The Dynamic Model of the UR10 Robot and Its ROS2 Integration,” in IEEE Transactions on Industrial Informatics, doi: 10.1109/TII.2025.3534415.

The library InverseDynamicsSolverUR10 depends on the following files, automatically generated with MATLAB:

• getCoriolisCurrents: given the 6X1 vector of positions and the 6X1 vector of velocities, both in joint space, it computes the 6x1 vector of currents related to Coriolis effects, expressed in A;
• getCurrents: given the 6X1 vector of positions, the 6X1 vector of velocities and the 6X1 vector of accelerations, all in joint space, it computes the 6x1 vector of currents without the friction effect, expressed in A.
• getGravityCurrents: given the 6x1 vector of positions in joint space, it computes the 6x1 vector of currents due to gravity, expressed in A;
• getInertiaCurrents: given the 6x1 vector of positions in joint space, it computes the 6x6 inertia matrix, expressed in A*s^2;

The dynamics solver implements the inverse_dynamics_solver::InverseDynamicsSolver class. Since methods that output torques are expected by the parent, this plugin uses the previously discussed current-based methods, along with the motor gains, to implement the parent class’ methods.

How to build

To build this package, run the following from the root of your colcon workspace:

colcon build --packages-up-to ur10_inverse_dynamics_solver
source install/setup.bash

Demo

You can evaluate the solver using the demo, whose configuration for the UR10 robot is provided though a launch file. The demo reads a bag file containing a sequence of sensor_msgs/msg/JointState messages and, for each state, computes the corresponding torques according to the InverseDynamicsSolverUR10 solver, which are saved in another bag file.

Run the demo

To launch the UR10 demo, run the following:

ros2 launch ur10_inverse_dynamics_solver evaluate_solver_ur10.launch.py

By default, the demo reads the ur10_exciting_trajectory.db3 bag file, and produces the output under the ur10_exciting_trajectory_real_torques folder (created under the current working directory), with the computed torques written on the /torques topic. You can change this configuration with

ros2 launch ur10_inverse_dynamics_solver evaluate_solver_ur10.launch.py input_bag:=<my_bag_file> output_bag:=<my_output_folder> topic:=<my_output_topic>

Visualize the results

Please refer to the parent class documentation to visualize the results, i.e. the evaluation of joint torque signals on input_bag, stored in output_bag.

How to test

The test consists in validating the solver against a trajectory, on which reference joint positions, velocities and accelerations are stored, and ground-truth joint efforts are specified. The ground truth is computed with MATLAB, by using an estimated model in regressive form. The test checks that this library computes the same values as the ground truth.

To build and execute the test, run the following:

colcon test --packages-select ur10_inverse_dynamics_solver

To see the results, run the following:

colcon test-result --all --verbose

The expected output is the following:

build/ur10_inverse_dynamics_solver/Testing/20240510-0742/Test.xml: 1 test, 0 errors, 0 failures, 0 skipped
build/ur10_inverse_dynamics_solver/test_results/ur10_inverse_dynamics_solver/launch_test_ur10_inverse_dynamics_solver.launch.py.xunit.xml: 2 tests, 0 errors, 0 failures, 0 skipped

Summary: 3 tests, 0 errors, 0 failures, 0 skipped

Optional analysis

If you wish to see the INFO messages printed on console during the test, run the following:

colcon test --packages-select ur10_inverse_dynamics_solver --event-handlers console_cohesion+

The expected output should contain the following line:

100% tests passed, 0 tests failed out of 1

Further details

The reference bag file validation_trajectory.db3 was originally computed for ROS Noetic. It was converted for ROS2 Humble with the rosbags-convert tool. Given the <ros1_bag_file>, the following command has been launched to generate the ROS2 bag file:

rosbags-convert --src <ros1_bag_file>.bag --dst validation_trajectory/ --src-typestore ros1_noetic --dst-typestore ros2_humble

The output is then generated in the validation_trajectory/ local folder, containing the new bag file and metadata.yaml.

Note 1: If you don’t have rosbags-convert in your system, you can install it with

pip3 install rosbags>=0.9.11

Note 2: It is possible that rosbags-convert is not in your Python path by default. However, you can launch its executable with

~/.local/bin/rosbags-convert --help

For more details about this tool, please see this guide.

Citation

If you find this work useful, please cite it as

@article{Petrone_2025,
    title={The Dynamic Model of the UR10 Robot and Its ROS2 Integration},
    ISSN={1941-0050},
    url={http://dx.doi.org/10.1109/tii.2025.3534415},
    DOI={10.1109/tii.2025.3534415},
    journal={IEEE Transactions on Industrial Informatics},
    publisher={Institute of Electrical and Electronics Engineers (IEEE)},
    author={Petrone, Vincenzo and Ferrentino, Enrico and Chiacchio, Pasquale},
    year={2025},
    pages={1–11}
}

Changelog for package ur10_inverse_dynamics_solver

0.1.1 (2025-04-03)

0.1.0 (2025-04-03)

• Commit for release
• Contributors: Vincenzo Petrone