ROS2 Control Demos

This repository provides templates for the development of ros2_control-enabled robots and a simple simulation of a robot to demonstrate and prove ros2_control concepts.

Goals

The repository has two goals:

1. It provides templates for faster start of implementing own hardware and controllers;
2. The repository is a validation environment for ros2_control concepts, which can only be tested during run-time (e.g., execution of controllers by the controller manager, communication between robot hardware and controllers).

Description

The repository is inspired by ros_control_boilerplate repository from Dave Coleman. The simulation has three parts/packages:

1. The first package, ros2_control_demo_communication_headless, uses scripts to simulate communication to and movements of virtual hardware. This package does not have any dependencies except on the ros2 core packages and can, therefore, be used on SoC-hardware of headless systems.
2. The second package, ros2_control_demo_communication_gazebo, uses a gazebo simulator to simulate the RRBot and its physics. This package is useful to test the connection of ros2_control to the gazebo simulator and to detect any missing plugins.
3. The third package holds template/example files for ros2_control enabled robots and controllers. The intention of those files is to simplify start with ros2_control and to enable faster integration of new robots and controllers.

This repository demonstrates the following ros2_control concepts:

• Creating of hardware_interface for a Robot, Sensor, and Actor
• Creating a robot description in the form of YAML files
• Loading configuration and starting robot using launch files
• Control of two joints of RRBot
• Using simulated robots and starting ros_control with gazebo simulator
• Implementing of controller switching strategy for a robot
• Using joint limits and transmission concepts in ros2_control
• TBD

Getting Started with ROS2 Control

To test demo_robot start launch file with:

ros2 launch ros2_control_demo_robot demo_robot_launch.py

for headless version of the demo_robot or

ros2 launch ros2_control_demo_robot demo_robot_modular_launch.py

for headless modular version of the demo_robot which uses separate interfaces for its sensors and actuators.

Class Diagram of demo_robot

The figure hereunder depicts the class diagram of ros2_control_demos metapackage, i.e., demo_robot, together with used interfaces and classes from ros2_control package. Diagram gives an overview of the components needed for a robot that is ROS2-Control compatible. In the middle of the diagram (no color), entities are core components of ros2_control. Green colored entities are "ROS2-Control"-standardized data structures, hardware representations, and communication interfaces. Blue colored is the implementation of demo_robot. A large amount of classes is for the exemplary purpose, therefore don't worry you probably don't need so many different interfaces and classes.

Making a Robot for ROS2-Control Compatible

Before starting the implementation of your robot, please check the following diagram: