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IntelRealSense / realsense-ros

ROS Wrapper for Intel(R) RealSense(TM) Cameras
http://wiki.ros.org/RealSense
Apache License 2.0
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Local ROS Topics Possibility? #2774

Closed h2jaafar closed 1 year ago

h2jaafar commented 1 year ago

Hello team,

I had a conceptual question.

My experiments require me to use a high number of realsense cameras (20 cameras), each recording depth and rgb. Currently, I am using launch files to launch modified versions of rs_launch with my required parameters.

The main aim of this is to simply record the topics as rosbags on a local Nvidia jetson that each camera is connected to. So for example,

robot_1_d435i/camera/color/image_raw robot_1_d435i/camera/depth/image_rect_raw and the necessary topics

My question is: Can I publish these topics only locally? i.e, is there a way to publish them such that I can record a rosbag, but not publish them onto my local network. As all the bandwidth is causing the network to get overloaded.

MartyG-RealSense commented 1 year ago

Hi @husseinalijaafar Would it be possible to add a local external storage drive such as an SSD to your Jetson and then install ROS and the RealSense ROS wrapper to that drive and launch from that location so that the rosbags are stored locally on that drive?

An example of an SSD external drive installation guide for Jetson models such as Xavier is here:

https://jetsonhacks.com/2020/05/29/jetson-xavier-nx-run-from-ssd/

h2jaafar commented 1 year ago

Hi Marty

Thanks for your feedback.

So the problem isn't with the storage bandwidth, rather network bandwidth. I am recording the rosbags locally on a U90 micro sd card, it can handle the bandwidth.

I want to essentially isolate the real sense topics from the network if possible.

MartyG-RealSense commented 1 year ago

The only way that I can think of to competely isolate RealSense ROS topics from a network would be to install Ubuntu, ROS and the RealSense ROS wrapper onto the micro SD card and boot the Jetson from that card.

h2jaafar commented 1 year ago

Hi Marty. I am currently doing that. I am launching the topics from the jetson directly, and I want to record the topics on the jetson BUT also not broadcast certain topics on the network. But I want to keep publishing other topics.

I guess it is not possible, they will be broadcast if the jetson is connected to the same network.

MartyG-RealSense commented 1 year ago

Individual topics can be removed by unsubscribing from them if you do not need them. Unsubscribing from topics can reduce CPU overhead.

h2jaafar commented 1 year ago

Thank you Marty. I think I am just going to isolate the jetson onto a seperate network

MartyG-RealSense commented 1 year ago

You are very welcome. Thanks very much for the update!

h2jaafar commented 1 year ago

In case it is helpful, after further research, you can change ROS_LOCALHOST_ONLY from 0 to 1 (export ROS_LOCALHOST_ONLY=1) to isolate the ROS instance onto the local host only, and prevent all ros topics from publishing and discovering the network topics to minimise network usage.

MartyG-RealSense commented 1 year ago

Thanks @husseinalijaafar :)