Differential Drive Robot Controller with Waypoint Navigation

Overview

This project implements a ROS 2-based differential drive robot controller that computes wheel RPM from velocity commands and a waypoint navigation system using a PID controller.

Features

• Computes wheel RPM from /cmd_vel commands.
• Publishes RPM values for motor control.
• Uses a PID controller to navigate between waypoints.
• Compatible with ROS 2 Humble and Gazebo Harmonic.

Installation

colcon build --packages-select car_nav2
source install/setup.bash

Usage

1. Run the RPM Publisher:

   ros2 run car_nav2 rpm_publisher

2. Run the Waypoint Navigator:

   ros2 run car_nav2 waypoint_navigation.py --ros-args -p waypoint_1_x:=2.0 -p waypoint_1_y:=1.0 -p waypoint_2_x:=4.0 -p waypoint_2_y:=3.0

Topics

• /cmd_vel (Input): Velocity commands.
• /left_wheel_rpm, /right_wheel_rpm (Output): Computed RPM values.
• /odom (Input): Odometry data for waypoint navigation.

Parameters

• wheelbase: Distance between wheels.
• wheel_radius: Wheel radius.
• max_rpm: Maximum RPM limit.
• kp, ki, kd: PID controller gains.

Testing

ros2 topic pub /cmd_vel geometry_msgs/Twist '{linear: {x: 0.5}, angular: {z: 0.2}}'
ros2 topic echo /left_wheel_rpm
ros2 topic echo /right_wheel_rpm

License

MIT License