Fred - Machine States

note: Package for ROS 2 - C++/Python (CMake) based package

The fred2_machine_states package in ROS 2 is designed to manage various states of a robot, focusing on modes like MANUAL and AUTONOMOUS. The primary node, goal_mode.py, monitors joystick connectivity, collision alerts, and other safety parameters to determine the robot's state.

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Installation

1. Clone the repository into your ROS2 workspace:

cd ros2_ws/src
git clone https://github.com/AMRFrederico/fred2_machine_states.git

2. Build the package:

cd ros2_ws
colcon build

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Usage

Launch the package:

ros2 launch fred2_machine_states machine_states_launch.yaml

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Goal mode node

The goal_mode.py node is the core component of the fred2_machine_states package. It manages the robot's mode (MANUAL or AUTONOMOUS) and state (EMERGENCY, IN GOAL, MISSION COMPLETED, MANUAL, or AUTONOMOUS) based on various inputs.

Type: python

Name: main_robot

Namespace: machine_states

Parameters:

manual: index state for manual mode

autonomous: index state for autonomous mode

in_goali: index state when the robot reaches the goal

mission_completed: index state when the robot finished the course

emergency: index state when the robot cannot receive speed commands

To check available parameters

ros2 param list 

To check the parameter description

ros2 param describe /machine_states/main_robot <parameter name>

To check the parameter value

ros2 param get /machine_states/main_robot <parameter name>

To reload the parameters file

ros2 param load /machine_states/main_robot <path-to-parameter-config-file>

Subscribers

• /joy/machine_states/switch_mode (std_msgs/Bool): Switch between MANUAL and AUTONOMOUS mode.

• /robot_safety (std_msgs/Bool): Robot safety status, returns True when the robot is safe, and False when the robot is blocked by safe twist node

• /goal_manager/goal/mission_completed (std_msgs/Bool): Status of mission completion.

• /goal_manager/goal/reached (std_msgs/Bool): Status of reaching the goal.

• /odom/reset (std_msgs/Bool): Reset odometry command.

Publishers:

• /machine_states/robot_state (std_msgs/Int16): Current robot state

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Run

Default:

ros2 run fred2_machine_states robot_states.py --ros-args --params-file /home/ubuntu/ros2_ws/src/fred2_machine_states/config/params.yaml

Enable debug:

ros2 run fred2_machine_states robot_states.py --ros-args --params-file /home/ubuntu/ros2_ws/src/fred2_machine_states/config/params.yaml --debug

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Launch

Default:

ros2 launch fred2_machine_states machine_states.launch.py 

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