[Bug]: Disconnected problems when using free fleet for multiple Robot.

[elineight]

Before proceeding, is there an existing issue or discussion for this?

• I have done a search for similar issues and discussions.

OS and version

Ubuntu 22.04

Open-RMF installation type

Source build

Other Open-RMF installation methods

No response

Open-RMF version or commit hash

2.3.0

ROS distribution

Humble

ROS installation type

Source build

Other ROS installation methods

No response

Package or library, if applicable

No response

Description of the bug

We got a project that include the management feature of RMF (mainly about the collision avoidance and traffic control) with multiple Robots. We got our Robots connect to a server PC (which run the RMF's core) through Wifi, and the connection is establish by the free fleet (our Robots use navigation stack of ROS 2 to move) with a server and multiple client. The project is running stably with 1 to 3 robots but when the number of robot is > 4 just one of them is working fine, the other can not update their position to RMF's server (the frequency of the update position action is 5Hz) and that where everything get messy. I have tried many way to config the CycloneDDS but it was inefficient

Steps to reproduce the bug

1. Launch RMF's core
2. Launch free fleet's server on server PC
3. Launch each Robot navigation and free fleet's client
4. The problem start when the number of robot is higher than 4

Expected behavior

No response

Actual behavior

No response

Additional information or screenshots

No response

[s-w3i]

Hi, I was wondering if you found any solutions for this issue. I'm encountering the same problem when running my own simulation with more than four robots. The server doesn't discover all the clients. Thanks!

[aaronchongth]

We have observed vastly different performances using raw CycloneDDS in the past, highly dependent on network settings and DDS configurations. So unfortunately it is unclear how it can be resolved reliable if DDS is still used.

However with #145 merged, we are currently utilizing zenoh bridges between robots and the fleet adapter, which should have a significant increase in reliability as long as a zenoh router is set up properly in the network. It helps that zenoh is easier to configure too.