ROS 2 Quick Start

Goal: Set up the RBQ ROS 2 SDK, connect to the robot (or simulator), and send your first motion commands via ROS 2 topics.

The RBQ ROS 2 SDK enables:

• Robot control — posture commands, gait switching, velocity-based navigation
• Sensor feedback — IMU, foot contact, battery state, and more as ROS 2 topics
• Vision streaming — front, rear, and downward camera data
• RViz2 visualization — real-time robot state and LiDAR display

System Requirements

Component	Requirement
OS	Ubuntu 22.04
ROS 2	Humble
Python	3.8 / 3.9 / 3.10

Installation

1. Install ROS 2 Humble

cd <your workspace>/RBQ
sudo bash scripts/ex/install/ros.bash
source /opt/ros/humble/setup.bash
sudo rosdep init && rosdep update

2. Build the RBQ ROS 2 Package

cd rbq_ros2_msgs
colcon build --symlink-install
source install/setup.bash

3. Start the Robot (or Simulator)

Start the RBQ motion stack before launching ROS 2 nodes. In simulation:

bash scripts/sim.bash

On the real robot, ensure Auto Start has been completed.

4. Launch the ROS 2 Node

ros2 launch rbq_bringup rbq_bringup.launch.py

Quick Start Commands

Step 1. Switch to HighLevel Command Mode

i

NOTE

To control the robot with HighLevelCommand topics, you must switch to HighLevel mode first. The default mode is JoyStick mode.

true	HighLevel mode — accepts /rbq/motion/cmd_highLevel
false	JoyStick mode — robot controlled by joystick (default)

ros2 topic pub --once /rbq/motion/switchControlMode std_msgs/msg/Bool "{data: true}"

Step 2. Auto Start

⚠

CAUTION

Before running autoStart, ensure the robot is in the correct initial pose on a flat surface.

ros2 topic pub --once /rbq/motion/autoStart std_msgs/msg/Bool "{data: true}"

Step 3. Gait Transition

Gait ID	State	Command
0	Sit	ros2 topic pub --once /rbq/motion/switchGait std_msgs/msg/Int8 "{data: 0}"
1	Stand	ros2 topic pub --once /rbq/motion/switchGait std_msgs/msg/Int8 "{data: 1}"
3	Walk	ros2 topic pub --once /rbq/motion/switchGait std_msgs/msg/Int8 "{data: 3}"

Full gait state table (including RL gaits): software/ROS2 — Topics

Step 4. Send Velocity Commands

Once in Walk mode (gait_id: 3):

# Move forward at 0.3 m/s
ros2 topic pub --once /rbq/motion/cmd_highLevel rbq_msgs/msg/HighLevelCommand \
'{header: {stamp: {sec: 0, nanosec: 0}, frame_id: "base"},
  identifier: "walk_fwd",
  vel_x: 0.3, vel_y: 0.0, omega_z: 0.0,
  roll: 0.0, pitch: 0.0, yaw: 0.0,
  delta_body_h: 0.0, delta_foot_h: 0.0,
  gait_state: 3, gait_transition: false}'

Key Topics at a Glance

Topic	Type	Direction	Description
/rbq/motion/autoStart	Bool	Publish	Trigger Auto Start
/rbq/motion/switchGait	Int8	Publish	Switch gait state
/rbq/motion/switchControlMode	Bool	Publish	HighLevel / Joystick toggle
/rbq/motion/cmd_highLevel	HighLevelCommand	Publish	Velocity + gait command
/rbq/sensor/imu	Imu	Subscribe	IMU data
/rbq/sensor/jointState	JointState	Subscribe	Joint positions/velocities
/rbq/sensor/battery	BatteryState	Subscribe	Battery level

For the full topic list (60+ topics including vision, manipulation, and SLAM), see:

Full ROS 2 Topic Reference →

RViz2 Visualization

ros2 launch rbq_bringup rbq_rviz.launch.py

Related

• Full ROS 2 Reference
• API Guide
• Developers Guide
• Concept