[Re-write] Free fleet adapter using easy-full-control fleet adapter and zenoh bridges

[aaronchongth]

New feature implementation

A large motivation of this re-write, is to fully utilize the well tested tools already available in the ROS ecosystem and Zenoh, and also take advantage of python bindings as much as possible, to allow for easier iterations, testing and contributions.

The use of Zenoh bridges will hopefully also minimize disruption to any existing robot navigation stack, and can be spun up with just a standalone binary with the appropriate configuration file.

The legacy implementation can still be found at the legacy branch.

• re-implemented free_fleet using easy_full_control, based off the fleet_adapter_template, will allow setting up of perform actions, Support perform_action feature of the fleet adapter #116, [Feature request]: Add /robot_state topic published from free_fleet_server #141
• fleet adapter to use zenoh as the main way of communicating with robots
• change approach to use zenoh-bridge-ros2dds as a drop-in method of bridging required ROS 2 topics and actions between robot and fleet adapter
• supports the nav2 stack with the simple /navigation_to_pose action, ROS 2 navigation stack client #84
• using pycdr2 to serialize and deserialize messages, with required message definitions fleshed out, Question on message generation #129
• examples using existing simulations from nav2_bringup
• updated README, https://github.com/open-rmf/free_fleet/blob/easy-full-control/README.md
• supports Jazzy (other distros not tested yet), What are the plans on moving to humble (Ubuntu 22.04)? #138
• linting, Add style linting #100

Architecture

This architecture and the use of Zenoh bridges will ideally improve the integration experience, with just setting up the zenoh-bridge-ros2dds and its configuration, instead of building and running a separate node.

This PR does not support the ROS 1 navigation stack, the diagram is just for illustrating the proposed architecture once it is implemented down the road.

Single robot example using official nav2_bringup's tb3_simulation

Two robots example using official nav2_bringup's unique_multi_tb3_simulation

Although the two robot simulation example is just for testing purposes as it uses a different architecture as intended

Next TODOs (over subsequent PRs)

• hardware testing
• attempt to optimize tf messages (not all are needed)
• ROS 1 nav support
• map switching support
• docking support
• support for Rolling
• docker images
• releases
• testing and support for other RMW implementations

There are plenty of TODOs left, but this is the bare minimum testable and usable state

[xiyuoh]

Thank you for revamping free fleet! Tried out the examples and things are looking fantastic. I was able to bring up both single and multiple TB3 tests by following the instructions on README.

Left some minor comments for the README that are mostly about typos and clarity. For the fleet/robot adapter, I was primarily looking out for edge cases where self.nav_goal_id might fall out of sync with self.execution and catching any scenarios where the execution object is left unattended if self.nav_goal_id is set to None. This may lead to RMF not sending any subsequent commands, or sending outdated nav commands if replans are not being called prompty.

[PVijayaGanesh]

Hi I did Free fleet adapter using easy-full-control fleet adapter and zenoh bridges
Steps I follow:

1. Install humble rmf

2. clone the branch easy full controll free fleet ( git clone -b easy-full-controll <> )

3. zenoh v11 setup i did ..

4. ros2 run free_fleet_examples test_navigate_to_pose.py
   --frame-id map
   --namespace turtlebot3_1
   -x 1.808
   -y 0.503

   This command is working... i sends the goal and robot is moving

   5. when the launch free fleet adapter i got this issue..

How can i resolve this...

@xiyuoh @aaronchongth

[codecov]

Codecov Report

Attention: Patch coverage is 63.63636% with 164 lines in your changes missing coverage. Please review.

Please upload report for BASE (main@0909836). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
..._fleet_adapter/free_fleet_adapter/fleet_adapter.py	0.00%	112 Missing ⚠️
...t_adapter/free_fleet_adapter/nav2_robot_adapter.py	72.61%	40 Missing and 6 partials ⚠️
..._fleet_adapter/free_fleet_adapter/robot_adapter.py	79.31%	6 Missing ⚠️

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  Branches        ?       59           
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  Misses          ?      158           
  Partials        ?        6           

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[aaronchongth]

Heads up @xiyuoh when you try it out again

While setting up static and integration tests, I've found that setting up a zenoh router between the bridges and the free_fleet_adapter provides the best stability and repeatability (IRL and in CI). Folks can reference the docker compose file.

I've updated the documentation, tests and architecture diagrams.

This is not a big change as it was already expected that folks will need to use a zenoh router eventually when setting up everything as a distributed system.