multipanda_ros2

A sim- and real Panda robot integration based on the ros2_control framework

This project implements most features from the original franka_ros repository in ROS2 Humble, specifically for the Franka Emika Robot (Panda). This project significantly expands upon the original franka_ros2 from the company, who dropped the support for the Pandas.

Additionally, multi-arm mujoco simulation has been integrated, meaning you can now run the same controller on both simulated and real robots. The simulation is designed as a plugin to the mujoco_ros_pkg.

The current version relies on a fork of the repository, which implements the ros2_control plugin as well as a generic SystemInterface for simple robot setups (e.g. a Panda arm mounted on a mobile base). This means, you should install the fork, not the original repo, until the two have been merged.

Work is ongoing to integrate FR3 into the architecture.

Documentation

Documentation for this project is available here.

Working features

More thorough information is available in the documentation.

• Real robot:
  • FrankaState broadcaster
  • All control interfaces (torque, position, velocity, Cartesian).
  • Example controllers for all interfaces
  • Controllers are swappable using rqt_controller_manager
  • Runtime franka::ControlException error recovery via ~/service_server/error_recovery
    • Upon recovery, the previously executed control loop will be executed again, so no reloading necessary.
  • Runtime internal parameter setter services much like what is offered in the updated franka_ros2
• Sim robot:
  • Same as the real robot, except Cartesian command interface is not available, and there is no plan to implement this for now.
  • Gripper server with identical interface to the real gripper (i.e. action servers)
  • Example controllers for the real single-arm listed above, that correspond to those interfaces, work out of the box.
  • FrankaState implements the basics: torque, joint position/velocity, O_T_EE and O_F_ext_hat.
  • Model provides all the existing functions: pose, zeroJacobian, bodyJacobian, mass, gravity, coriolis.
    • Gravity for now just returns the corresponding qfrc_gravcomp force from mujoco.
    • Coriolis = qfrc_bias - qfrc_gravcomp
  • Camera is available as part of mujoco_ros_pkg’s features. You can simply add a <camera> object in your mujoco XML file, and the package will handle them.
  • With the forked repository’s mujoco_ros2_control_system package, you can easily add components with additional degrees of freedom to your robot. Take a look at garmi_packages/garmi_description/robots/*.ros2_control.xacro for an example on how to do this.

Known issues

• Joint position controller might cause some bad motor behaviors. Suggest using torque or velocity for now.
• The default franka_moveit_config package depends on warehouse_ros_mongo, which has been deprecated. It has been changed to warehouse_ros_sqlite for now to ensure that rosdep install works properly. For now, please refer to this discussion here for a potential solution; once a proper solution has been identified, it will be added.

Installation guide

(Tested on Ubuntu 22.04, ROS2 Humble, Panda 4.2.2 & 4.2.1, libfranka 0.9.2 and MuJoCo 3.2.0) On a computer running Ubuntu 22.04 and real-time kernel (if you wish to use it with a real robot), do the following:

1. Install ROS2 Humble by following their [instructions][humble-instructions] and create a workspace.
2. Install library dependencies:
   • Install Eigen 3.3.9. Remove Eigen 3.4.0 if that was installed from following the libfranka steps.
     • Some functions will break if you use Eigen 3.4.0, and will fail to compile.
   • Install dq-robotics C++ version
3. Build libfranka 0.9.2 from source:
   • Install dependencies: sudo apt-get install -y build-essential cmake git libpoco-dev libfmt-dev
     • (Ideally, you should already have build-essential, cmake and gitalready installed)
   • Clone the libfranka repo: git clone https://github.com/frankaemika/libfranka.git && mkdir /home/user/Libraries/libfranka
     && cd libfranka \
   • Check out 0.9.2 and update the submodules:

        cd libfranka
        git checkout 0.9.2 
        git submodule init 
        git submodule update 
        

- Build the library, and install it to the directory of your choice (here, `~/Libraries/libfranka`)

        mkdir build && cd build
        cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_TESTS=OFF -DCMAKE_INSTALL_PREFIX=/home/user/Libraries/libfranka ..
        cmake --build .
        cmake --install .
        

1. Build MuJoCo 3.2.0 (required by mujoco_ros_pkg) from source by following the [instructions][mujoco-instructions].
2. Install mujoco_ros_pkg, specifically this fork.
3. Clone this repository (i.e. the multipanda) into your workspace’s src folder.

4. Install the dependencies by running this rosdep command from the workspace root:

   rosdep install --from-paths src -y --ignore-src

5. Export the {mujoco/libfranka}/lib/cmake directories as a CMAKE_PREFIX_PATH in your environment, i.e.
   • in ~/.bashrc, export CMAKE_PREFIX_PATH={path to mujoco installation}/lib/cmake:{path to libfranka installation}/lib/cmake

6. Add the build path to your LD_LIBRARY_PATH by adding the following line to your ~/.bashrc:

   export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:{path to libfranka install}/lib:{path to mujoco's install}/lib

7. Source the workspace, then in your workspace root, call:

   colcon build --cmake-args -DCMAKE_BUILD_TYPE=Release

   • The paths to mujoco and libfranka are added to CMAKE_PREFIX_PATH, so no separate args are needed.
   • The MuJoCo path is the INSTALLED folder’s directory. The lib folder should only have the two .so files, and a folder called cmake.
   • Likewise, the libfranka path should contain the cmake folder and the .so files.
8. To run:
   • Single arm:
     1. with real robot, source the workspace, and run:
        • Default: ros2 launch franka_bringup franka.launch.py robot_ip:=<fci-ip>.
        • Multi-mode: ros2 launch franka_bringup multimode_franka.launch.py robot_ip:=<fci-ip>.
        • arm_id is fixed to panda.
     2. for simulated robot, source the workspace, and run:
        • Default: ros2 launch franka_bringup franka_sim.launch.py.

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