actor_estop

ROS package for Emergency Stopping functionality on LTU ACTor vehicles. The system consists of two components: the core estop manager (core_estop_manager.py) and the edge estop manager (edge_estop_manager.py). The core system runs on the main computer, while the edge system runs on a remote device, such as a Raspberry Pi.

Core Estop Manager (core_estop_manager.py)

• Sends heartbeats to the edge manager to verify its own health.
• Monitors heartbeats from the edge manager, if it times out for any reason, it will trigger a software estop (brakes).

Edge Estop Manager (edge_estop_manager.py)

• Sends heartbeats to the core manager to verify its own health.
• Monitors heartbeats from the core manager, if it times out for any reason, it will trigger an estop.
• Monitors the physical button and wireless button loops (via GPIO) and triggers an estop/reset accordingly.
• Monitors trigger and reset topics and triggers an estop/reset accordingly.
• Triggers estop activation or reset via relay board wired to the Drive-By-Wire controller.

Note: If the relay board or rpi is powered off or looses communication, (normally open, active off) hardware estop is triggered automatically. To disable hardware estop, it needs to be physically bypassed.

Dependencies

• ROS Noetic
• dbw_polaris_msgs: ROS messages for controlling a DataSeed Drive-By-Wire system installed in ACTor.
• gpiozero: Python GPIO library (install using pip3 install -r requirements.txt if not already installed in Raspberry Pi).

Installation

1. Clone this repository into your ROS workspace's src folder:

   git clone <repository_url>
   

2. Build the ROS package once in the workspace:

   catkin build actor_estop
   

Usage

1. Run the core estop manager on the main computer:

   rosrun actor_estop core_estop_manager.py
   

2. Run the edge estop manager on the remote device (e.g. Raspberry Pi):

   rosrun actor_estop edge_estop_manager.py
   

Configuration

• Modify the GPIO pin configurations in the edge estop manager script (edge_estop_manager.py) to match your hardware setup.
• Adjust the heartbeat rate and timeout parameters in both scripts as needed for your system requirements.
• Setup autorun on boot (only on edge device) instructions: (coming soon)

Contributing

Contributions are welcome! If you find any issues or have suggestions for improvements, please open an issue or submit a pull request on GitHub.

License

This software is released under the MIT License.