juancarlos-tiquerangel/turtlebot3_cpp

MPC in ros2 using C++

TUTLEBOT3 using simple MPC without constrains

This header file contains a class called turtlebot3_MPC that implements a simple Model Predictive Controller (MPC) for the TurtleBot3 robot. The MPC is used to control the robot's velocity and orientation to follow a given trajectory. The class controller also includes a Proportional-Integral-Derivative (PID) component for compare the robot's motion.

Dependencies

• eigen3: a C++ template library for linear algebra.
• rclcpp: the ROS 2 C++ client library.
• std_msgs: a ROS 2 package for standard message definitions.
• geometry_msgs: a ROS 2 package for geometry-related message definitions.
• nav_msgs: a ROS 2 package for navigation-related message definitions.
• sensor_msgs: a ROS 2 package for sensor-related message definitions.

Installation

1. Clone the repository to your ROS2 workspace:

   cd ~/your_ros2_ws/src`
   git clone https://github.com/JuanCarlos-TiqueRangel/turtlebot3_cpp.git
   

2. Build the package:

   cd ~/your_ros2_ws
   colcon build --packages-select turtlebot3_cpp
   

Member Functions

The turtlebot3_MPC class has the following member functions:

double simple_MPC(double w, double yaw, double ref)

• A simple model predictive control (MPC) function that controls the robot's movement.
• Takes three arguments:
  • w - Desired angular velocity of the robot.
  • yaw - Current orientation of the robot in radians.
  • ref - Desired orientation of the robot in radians.
• Returns the control action uk_mpc. This control tecnique comes from the MPC strategy from Predictive Control With Constraints: MacIejowski book. Also there is a related paper of a real implementation in a skid-steering robot here.

double simple_PID(double error)

• A simple proportional-integral-derivative (PID) function that controls the robot's movement.
• Takes one argument:
  • error - Error in the orientation of the robot.
• Returns the control action uk_pid.

Future Work

constraints and MIMO controller will be add.

Notes

• This file assumes that the robot is using ROS2 as the middleware.
• This file has been tested with the TurtleBot3 robot platform.

License

This code is released under the MIT License. Feel free to modify and use it in your own projects.