Barrett WAM ROS 2 Humble Driver

ROS 2 Humble driver for controlling a Barrett WAM arm over CAN bus through libbarrett.

This repository ports the original ROS 1 Barrett WAM interface to ROS 2 while keeping the low-level hardware access in libbarrett. It has been validated on a local control PC with a 7-DOF WAM, SocketCAN, ROS 2 Humble, and Ubuntu 22.04-style system dependencies.

✨ Highlights

• 🤖 ROS 2 Humble ament_cmake build.
• 📡 CAN-bus WAM control through patched libbarrett.
• 🧩 ROS 2 interfaces for WAM state, realtime commands, and service commands.
• 🖐️ Optional BarrettHand and force/torque sensor support when discovered by libbarrett.
• 🛡️ Conservative launch defaults for first-time hardware bring-up.
• 🧪 Helper tools for rqt and safe single-joint motion diagnostics.

📁 Repository Layout

wam_node/              ROS 2 WAM hardware node
barrett_hand_node/     ROS 2 standalone BarrettHand node
wam_msgs/              ROS 2 custom messages
wam_srvs/              ROS 2 custom services
wam_teleop/            ROS 2 joystick teleoperation
scripts/               Small user-facing test utilities
libbarrett/            Patched libbarrett source, if vendored in this repo
wam_demos/             Legacy ROS 1 package, ignored by colcon
perception_palm/       Legacy ROS 1 package, ignored by colcon

🧭 Tested Platform

Recommended target:

• 🐧 Ubuntu 22.04
• 🛰️ ROS 2 Humble
• 🔌 SocketCAN or PEAK PCAN CAN interface exposed as can0
• 🦾 Barrett WAM with safety pendant
• 📚 Patched libbarrett built from this repository or from your patched libbarrett fork

Notes:

• ROS 2 Humble officially targets Ubuntu 22.04.
• ⚠️ The WAM is real hardware. Keep the E-stop reachable, clear the workspace, and do not run motion commands until the arm is physically safe.
• The original ROS 1 demo and Perception Palm packages are not ported in this tree and are intentionally ignored by colcon.

📦 Install Dependencies

Install ROS 2 Humble first by following the official ROS 2 installation guide for Ubuntu 22.04. Then install the build and runtime packages used by this driver:

sudo apt update
sudo apt install -y \
  build-essential \
  cmake \
  git \
  can-utils \
  libboost-system-dev \
  libboost-thread-dev \
  libconfig++-dev \
  libeigen3-dev \
  libgsl-dev \
  libncurses5-dev \
  python3-colcon-common-extensions \
  ros-humble-joy \
  ros-humble-rqt \
  ros-humble-rqt-common-plugins \
  ros-humble-rqt-service-caller

If Conda is active, use the system ROS tools when building and running:

conda deactivate || true
source /opt/ros/humble/setup.bash

🛠️ Build and Install Patched libbarrett

This ROS 2 port requires a patched libbarrett for modern Ubuntu/libconfig/C++ toolchains. The patch set includes:

• 🧭 Compatibility with stock Ubuntu libconfig++.
• 🧱 C++17-compatible public headers.
• 📡 SocketCAN build support for non-realtime Linux control.
• 🛡️ A more robust CAN receive buffer during recovery/reconnect.
• 📦 COLCON_IGNORE so colcon does not try to build libbarrett as a ROS package.

You should clone libbarrett-ROS2repo to your local PC and then build it as following instructions:

cd
git clone https://github.com/gaolongsen/libbarrett-ROS2.git
cd libbarrett-ROS2
mkdir -p build
cd build
cmake .. \
  -DNON_REALTIME=true \
  -DWITH_PYTHON=OFF \
  -DCMAKE_BUILD_TYPE=Release
make -j$(nproc)
sudo make install
sudo ldconfig

Verify installation:

ldconfig -p | grep libbarrett
test -f /usr/local/share/barrett/barrett-config.cmake && echo "Barrett CMake config OK"
test -f /usr/local/include/barrett/detail/libconfig_c_setting.h && echo "Patched headers OK"

🔌 Configure CAN

Before you start this section, make sure that you have the CAN bus device. We recommend use PCAN USB Adapter as shown below to ensure you can successfully install the driver 100% to save your time for driver. (WIFI version is on the way!)

Bring up the CAN interface before starting the WAM node:

sudo modprobe can
sudo modprobe can_raw
sudo modprobe can_dev

sudo ip link set can0 down || true
sudo ip link set can0 up type can bitrate 1000000 restart-ms 100
ip -details -statistics link show can0

Optional passive bus check:

candump -L can0

Do not leave candump or any other CAN reader/writer running while starting wam_node.

🧱 Build the ROS 2 Workspace

From the repository root:

cd ~/WAM-ROS2
source /opt/ros/humble/setup.bash
./build.sh
source install_ros2/setup.bash

Expected ROS 2 packages:

ros2 pkg list | grep -E 'wam_|barrett_hand_node'
ros2 pkg executables wam_node
ros2 pkg executables wam_teleop

🦾 First WAM Bring-Up

For first contact, run the executable directly so libbarrett can read terminal input during the zeroing prompt:

cd ~/WAM-ROS2
source /opt/ros/humble/setup.bash
source install_ros2/setup.bash
./install_ros2/wam_node/lib/wam_node/wam_node

Follow the safety pendant sequence:

1. Clear the workspace and keep E-stop reachable.
2. Release E-stop.
3. When prompted, press SHIFT + IDLE.
4. If prompted to zero, move the WAM to its physical home/zero pose and press Enter.
5. When prompted, press SHIFT + ACTIVATE.

After startup, verify ROS discovery:

ros2 node list
ros2 topic list -t
ros2 service list -t
ros2 topic echo --once /wam/joint_states

🚀 Launching wam_node

After the first bring-up is working, launch through ROS 2:

ros2 launch wam_node wam_node.launch.py

Launch arguments:

ros2 launch wam_node wam_node.launch.py --show-args

Important defaults:

• auto_gravity_comp:=true
  • Matches the original ROS 1 behavior.
  • Required for stable joint-position control on gravity-loaded joints.
• initialize_hand_on_startup:=false
  • Avoids automatic BarrettHand initialization during first WAM startup.
• hand_clearance_move_on_startup:=false
  • Avoids the original automatic joint-4 clearance move.
• home_velocity:=0.10
• home_acceleration:=0.10

For a slower home motion:

ros2 launch wam_node wam_node.launch.py home_velocity:=0.05 home_acceleration:=0.05

📡 ROS 2 Topics

State topics:

/wam/joint_states       sensor_msgs/msg/JointState
/wam/pose               geometry_msgs/msg/PoseStamped
/wam/move_is_done       std_msgs/msg/Bool
/fts/fts_states         geometry_msgs/msg/Wrench, if F/T sensor is present

Command topics:

/wam/cart_vel_cmd       wam_msgs/msg/RTCartVel
/wam/ortn_vel_cmd       wam_msgs/msg/RTOrtnVel
/wam/jnt_vel_cmd        wam_msgs/msg/RTJointVel
/wam/jnt_pos_cmd        wam_msgs/msg/RTJointPos
/wam/cart_pos_cmd       wam_msgs/msg/RTCartPos

Realtime command topics are timeout-based. If messages stop, the node returns to holding the current joint position.

🧰 ROS 2 Services

Core WAM services:

/wam/gravity_comp       wam_srvs/srv/GravityComp
/wam/go_home            std_srvs/srv/Empty
/wam/hold_joint_pos     wam_srvs/srv/Hold
/wam/hold_cart_pos      wam_srvs/srv/Hold
/wam/hold_ortn          wam_srvs/srv/Hold
/wam/joint_move         wam_srvs/srv/JointMove
/wam/pose_move          wam_srvs/srv/PoseMove
/wam/cart_move          wam_srvs/srv/CartPosMove
/wam/ortn_move          wam_srvs/srv/OrtnMove

Enable gravity compensation:

ros2 service call /wam/gravity_comp wam_srvs/srv/GravityComp "{gravity: true}"

Move to an absolute 7-DOF joint pose:

ros2 service call /wam/joint_move wam_srvs/srv/JointMove \
  "{joints: [0.0, -1.5, 0.0, 2.0, 0.0, 0.0, 0.0]}"

Move to the configured libbarrett home pose:

ros2 service call /wam/go_home std_srvs/srv/Empty "{}"

Important: /wam/go_home is not all-zero joints. For a typical 7-DOF wrist WAM the configured home pose is:

[0, -2, 0, 3.13, 0, 0, 0]

This value comes from /etc/barrett/calibration_data/wam7w/zerocal.conf or the corresponding WAM configuration selected by libbarrett.

🧪 Safe Joint Motion Test

Use the helper script to test one joint at a time. It reads the current joint state, adds a small delta to one joint, calls /wam/joint_move, waits for /wam/move_is_done, and prints final error.

cd ~/WAM-ROS2
source /opt/ros/humble/setup.bash
source install_ros2/setup.bash

scripts/wam_joint_nudge.py 1 0.02
scripts/wam_joint_nudge.py 1 -0.02

Test joints 1 through 7 slowly. Do not send the next command until the previous one finishes.

If Fast DDS prints shared-memory warnings such as Failed init_port, disable Fast DDS shared memory for the current terminal:

export RMW_FASTRTPS_USE_SHM=0

🖥️ rqt

Launch rqt from the repository helper so it uses the same ROS 2 workspace environment and avoids Conda/Snap/Qt library pollution:

cd ~/WAM-ROS2
./run_rqt_wam.sh --clear-config --force-discover

Open:

Plugins -> Services -> Service Caller

For /wam/joint_move, edit the joints expression from the default empty array to a 7-value Python list:

[0.0, -1.5, 0.0, 2.0, 0.0, 0.0, 0.0]

Do not publish to /wam/joint_states; it is a feedback topic, not a command topic.

🖐️ BarrettHand Node

For standalone BarrettHand control over CAN:

ros2 launch barrett_hand_node barrett_hand_node.launch.py

Example services:

ros2 service call /bhand/initialize std_srvs/srv/Empty "{}"
ros2 service call /bhand/open_grasp std_srvs/srv/Empty "{}"
ros2 service call /bhand/close_grasp std_srvs/srv/Empty "{}"
ros2 service call /bhand/grasp_pos wam_srvs/srv/BHandGraspPos "{radians: 1.0}"

🎮 Joystick Teleoperation

Start the WAM node first, then launch teleoperation:

ros2 launch wam_teleop wam_joystick_teleop.launch.py

The teleop node subscribes to /joy and publishes WAM realtime velocity commands.

🛟 Recovery After E-stop or Shaking

If the WAM shakes, behaves unexpectedly, or E-stop is pressed:

1. Press E-stop.

2. Stop wam_node.

3. Reset the CAN interface:

   sudo ip link set can0 down
   sudo ip link set can0 up type can bitrate 1000000 restart-ms 100

4. Restart wam_node.

5. Press SHIFT + IDLE.

6. Zero if prompted.

7. Press SHIFT + ACTIVATE.

8. Re-enable gravity compensation if needed:

   ros2 service call /wam/gravity_comp wam_srvs/srv/GravityComp "{gravity: true}"

Do not continue sending commands after serious shaking without restarting the node and recovering the safety state.

🔎 Troubleshooting

librcl_interfaces__rosidl_typesupport_cpp.so not found

You likely overwrote LD_LIBRARY_PATH. Source ROS 2 and prepend any local library path instead of replacing it:

source /opt/ros/humble/setup.bash
source install_ros2/setup.bash
LD_LIBRARY_PATH=$PWD/libbarrett/build/src:$LD_LIBRARY_PATH ./install_ros2/wam_node/lib/wam_node/wam_node

rqt loads Snap or Conda libraries

Use:

./run_rqt_wam.sh --clear-config --force-discover

If needed, use a fresh non-Snap terminal and deactivate Conda.

BusManager::storeMessage: Buffer overflow

Use the patched libbarrett in this repository. Rebuild and install it:

cd libbarrett/build
make -j$(nproc)
sudo make install
sudo ldconfig

Then reset CAN before reconnecting:

sudo ip link set can0 down
sudo ip link set can0 up type can bitrate 1000000 restart-ms 100

Joint commands are accepted but gravity-loaded joints do not move

Ensure gravity compensation is enabled:

ros2 service call /wam/gravity_comp wam_srvs/srv/GravityComp "{gravity: true}"

The default launch file enables it automatically with auto_gravity_comp:=true.

rqt sends 0-DOF request received

The Service Caller sent an empty array. For /wam/joint_move, the joints field must be a 7-element list.

WAM home target is unexpected

/wam/go_home uses the home pose from libbarrett configuration, usually in:

/etc/barrett/calibration_data/wam7w/zerocal.conf

Check that the installed Barrett calibration files match your physical WAM.

📖 Citation

If this repository is useful for your work, please cite or acknowledge the project repository and Barrett Technology's original ROS/libbarrett software.

📜 License

This repository is derived from Barrett ROS/libbarrett software. Keep the original license files and notices from upstream components when redistributing or modifying this code.