Omni-Bot

An omni-wheeled mobile robot for autonomous navigation.

What it does

• Simulates the bot in a 6×6 m walled test arena in Gazebo.
• Loads a pre-built map apriori (omni_navigation/maps/test_map.*) and localizes on it with AMCL.
• Autonomous navigation source→destination via Nav2.
• Manual terminal control via holonomic teleop_twist_keyboard (strafe + rotate).

Packages

Package	Purpose
omni_description	URDF/Xacro model: mecanum base, IMU, Pi camera, sim lidar, Gazebo plugins
omni_gazebo	Test world + simulation launch (Gazebo + spawn + robot_state_publisher)
omni_navigation	Pre-built map, Nav2 params, AMCL localization + navigation launch, RViz
omni_hardware	Stub driver nodes for the real Pi 4B / Arduino UNO / GY-9250 / Pi Camera 3
omni_bringup	Top-level launch: full sim+nav demo, and teleop

Note on the lidar: the physical robot has no lidar, but Nav2 + AMCL need a /scan. A 2D lidar is added in simulation only (sensors.xacro). On real hardware, add a lidar driver in hardware.launch.py, or convert the Pi Camera depth image to a LaserScan with depthimage_to_laserscan.

Prerequisites

ROS 2 Humble on Ubuntu 22.04, plus:

sudo apt update
sudo apt install -y \
  ros-humble-desktop \
  ros-humble-gazebo-ros-pkgs \
  ros-humble-xacro \
  ros-humble-joint-state-publisher-gui \
  ros-humble-navigation2 ros-humble-nav2-bringup \
  ros-humble-teleop-twist-keyboard \
  xterm

Build

cd omni_ws
rosdep install --from-paths src --ignore-src -r -y   # optional, resolves deps
colcon build --symlink-install
source install/setup.bash

Run

1. Full demo — simulation + map + AMCL + Nav2

ros2 launch omni_bringup sim_navigation.launch.py

Gazebo and RViz open. In RViz:

1. The map and the robot appear; AMCL starts pre-seeded at the spawn pose (-2, -2). If needed, use 2D Pose Estimate to correct it.
2. Click Nav2 Goal and pick a destination — the bot plans and drives there autonomously, avoiding the two interior obstacles.

2. Teleop Control

In a seperate terminal;

source install/setup.bash
ros2 run teleop_twist_keyboard teleop_twist_keyboard

Use u i o / j k l / m , . to translate and rotate. Press b to toggle holonomic mode, then hold Shift with a key to strafe sideways (mecanum). This publishes /cmd_vel, which drives the sim (and the Arduino bridge on real hardware). You can teleop and use Nav2 in the same session.

3. Just view the model

ros2 launch omni_description rsp.launch.py

4. Hardware stubs

On the Pi 4B (replaces Gazebo as the source of odom/scan/sensors):

ros2 launch omni_hardware hardware.launch.py     # then run navigation.launch.py

Fill in the TODO(hardware) blocks in omni_hardware/omni_hardware/*.py (serial to Arduino, MPU-9250 I2C, picamera2) and add a real lidar/scan source.

Make your own map

Drive around with teleop while running slam_toolbox, then ros2 run nav2_map_server map_saver_cli -f my_map, and point omni_navigation at the new my_map.yaml.

Topics used

Topic	Type	Direction
/cmd_vel	geometry_msgs/Twist	in (teleop / Nav2 → base)
/odom	nav_msgs/Odometry	out (planar_move / Arduino)
/scan	sensor_msgs/LaserScan	out (sim lidar)
/imu/data	sensor_msgs/Imu	out
/pi_camera/image_raw	sensor_msgs/Image	out
/map	nav_msgs/OccupancyGrid	out (map_server)
/goal_pose	geometry_msgs/PoseStamped	in (RViz Nav2 Goal)

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