Baxter ROS2

Baxter robot simulation in ROS2 Jazzy + Gazebo Harmonic, with a roadmap toward distributed motion planning via a custom ROS2 Action interface and Zenoh as RMW bridge.

Status: Phase 3 complete - MoveIt2 motion planning integrated and functional.
Phase 4 (Custom MoveArm action interface) next.

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Overview

This project brings Rethink Robotics' Baxter robot into a modern ROS2 stack. The long-term goal is a two-machine architecture where Gazebo runs the simulation on one machine while MoveIt2 and a high-level controller run on another, communicating over Zenoh instead of the default DDS middleware.

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Planned Architecture

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Repository Structure

baxter/src/
└── baxter/
    ├── baxter.urdf
    ├── gazebo_baxter/       # Gazebo Harmonic simulation
    │   ├── config/
    │   │   ├── ros_gz_bridge.yaml
    │   │   └── controllers.yaml     # ros2_control configuration
    │   ├── launch/
    │   │   └── gazebo.launch.py
    │   ├── urdf/
    │   │   ├── robots/
    │   │   │   └── baxter_gazebo.urdf.xacro
    │   │   └── sensors/            # Camera RGB, RGBD, IMU, LiDAR
    │   └── worlds/
    │       └── empty.sdf
    ├── baxter_description/             # URDF visualization + meshes
    │   ├── launch/
    │   │   └── display.launch.py
    │   ├── meshes/                 # STL/DAE files per link
    │   └── urdf/
    │       ├── robots/
    │       │   ├── baxter.urdf.xacro
    │       │   └── baxter_standalone.urdf.xacro
    │       └── sensors/
    └── baxter_moveit_config/           # MoveIt2 configuration
        ├── config/
        │   ├── baxter.srdf
        │   ├── joint_limits.yaml
        │   ├── kinematics.yaml
        │   ├── moveit_controllers.yaml
        │   ├── ompl_planning.yaml
        │   └── pilz_cartesian_limits.yaml
        ├── launch/
        │   ├── demo.launch.py          # Full MoveIt2 + Gazebo demo
        └── rviz/
            └── moveit.rviz

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Prerequisites

• ROS2 Jazzy
• Gazebo Harmonic
• ros-jazzy-ros-gz-bridge
• ros-jazzy-xacro
• ros-jazzy-robot-state-publisher
• ros-jazzy-ros2-control
• ros-jazzy-ros2-controllers
• ros-jazzy-gz-ros2-control
• MoveIt2:
  • ros-jazzy-moveit
  • ros-jazzy-moveit-ros-control-interface
  • ros-jazzy-moveit-planners-ompl
  • ros-jazzy-moveit-simple-controller-manager
  • ros-jazzy-moveit-ros-control-interface

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Getting Started

1. Clone and build

source /opt/ros/jazzy/setup.bash
git clone https://github.com/angysof16/BaxterMotionPlanning.git
cd BaxterMotionPlanning
colcon build --symlink-install
source install/setup.bash

2. Launch simulation (Gazebo only)

ros2 launch gazebo_baxter gazebo.launch.py

3. Launch with MoveIt2 (for motion planning)

ros2 launch baxter_moveit_config demo.launch.py

This launches:

• Gazebo Harmonic simulation
• ros2_control controllers
• MoveIt2 move_group node
• RViz2 with MoveIt plugin

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Usage

Verifying Controllers

Before sending any commands (via action calls or MoveIt2), always verify that controllers are active. Controller activation can sometimes fail during launch.

Check controller status:

ros2 control list_controllers

Expected output:

head_controller         joint_trajectory_controller/JointTrajectoryController  active
left_arm_controller     joint_trajectory_controller/JointTrajectoryController  active
right_arm_controller    joint_trajectory_controller/JointTrajectoryController  active
joint_state_broadcaster joint_state_broadcaster/JointStateBroadcaster          active

All controllers should show active status. If any controller shows inactive or unconfigured, see the Troubleshooting section below.

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Using MoveIt2 (Interactive Planning)

1. Launch the demo (if you haven't already):

   ros2 launch baxter_moveit_config demo.launch.py

2. In RViz:

   • Select Planning Group: right_arm or left_arm
   • Drag the interactive marker to set a goal pose
   • Click Plan to compute a trajectory
   • Click Execute to run it on the robot

3. The robot in Gazebo should move to match the planned trajectory.

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Testing Controllers via Action Calls (Command Line)

If you prefer to test controllers directly via action calls:

Move Right Arm

ros2 action send_goal /right_arm_controller/follow_joint_trajectory \
  control_msgs/action/FollowJointTrajectory \
  "{trajectory: {
    joint_names: [
      torso_right_upper_shoulder,
      right_upper_shoulder_lower_shoulder,
      right_lower_shoulder_upper_elbow,
      right_upper_elbow_lower_elbow,
      right_lower_elbow_upper_forearm,
      right_upper_forearm_lower_forearm,
      right_lower_forearm_wrist
    ],
    points: [
      {positions: [0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], time_from_start: {sec: 2}},
      {positions: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], time_from_start: {sec: 4}}
    ]
  }}"

Move Left Arm

ros2 action send_goal /left_arm_controller/follow_joint_trajectory \
  control_msgs/action/FollowJointTrajectory \
  "{trajectory: {
    joint_names: [
      torso_left_upper_shoulder,
      left_upper_shoulder_lower_shoulder,
      left_lower_shoulder_upper_elbow,
      left_upper_elbow_lower_elbow,
      left_lower_elbow_upper_forearm,
      left_upper_forearm_lower_forearm,
      left_lower_forearm_wrist
    ],
    points: [
      {positions: [0.5, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], time_from_start: {sec: 2}},
      {positions: [0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0], time_from_start: {sec: 4}}
    ]
  }}"

Move Head

ros2 action send_goal /head_controller/follow_joint_trajectory \
  control_msgs/action/FollowJointTrajectory \
  "{trajectory: {
    joint_names: [torso_head],
    points: [
      {positions: [0.5], time_from_start: {sec: 1}},
      {positions: [-0.5], time_from_start: {sec: 2}},
      {positions: [0.0], time_from_start: {sec: 3}}
    ]
  }}"

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Visualize URDF in RViz2 (without Gazebo)

ros2 launch baxter_description display.launch.py

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Troubleshooting

Controllers not activating automatically?

If ros2 control list_controllers shows any controller as inactive or unconfigured, activate them manually:

ros2 control switch_controllers \
  --activate joint_state_broadcaster \
  --activate right_arm_controller \
  --activate left_arm_controller \
  --activate head_controller

Verify all controllers are now active:

ros2 control list_controllers

All controllers should show active status.

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LiDAR not showing in Gazebo simulation?

If you see the error:

[GUI] [Err] [VisualizeLidar.cc:285] The lidar entity with topic '[/scan]' could not be found.

This is a known issue where Gazebo doesn't automatically visualize GPU LiDAR sensors. To fix it, manually list the sensor link:

gz model -m baxter -l lidar_sensor

Note: This command needs to be run after Gazebo is launched. The sensor will be visible in the GUI after executing the command.

See this StackExchange discussion for more details.

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Project Roadmap

Phase	Description	Status
1	Baxter URDF + Gazebo Harmonic simulation	✅ Done
2	ros2_control integration + joint trajectory controller	✅ Done
3	MoveIt2 motion planning for pick & place	✅ Done
4	Custom MoveArm action interface	In progress
5	Zenoh RMW bridge - two-machine architecture	Planned
6	Wii Remote teleoperation via joy + custom ROS2 node	Planned
7	FastDDS vs Zenoh latency benchmarks	Possible

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References

• ROS2 Jazzy docs
• Gazebo Harmonic
• MoveIt2
• ros2_control documentation
• MoveIt2 + ros2_control tutorial
• rmw_zenoh
• Macenski et al., Robot Operating System 2: Design, architecture, and uses in the wild, Science Robotics, 2022