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lost static frames of multicameras through rosbridge

Hi everyone,

I am facing the problem related to multicameras and rosbridge. I am using 3 Intel realsenses (1 D415 and 2 D435), and I would like to subscribe the topics /tf and /tfstatic of all camera to publish to another ros master (other computer) by using rosbridge (my side is rosbridge client). I can see whole the frames of all cameras in the graph of my computer (connected with 3 cameras). However, when I subscribe topics /tf and /tfstatic, then publish to another ros master (another computer), I just can see frames of 1 camera in another computer. I tried many ways, but cannot solve my problem. Can you please give me some advices?

Thanks in advances

Asked by Getchbold NT on 2019-08-13 05:05:58 UTC

Comments

Can you tell us a bit more about what you're trying. Are your two computers connected across the internet? Can you show us the node which is subscribing and publishing the TF topics, I'm not quite sure I understand what you're doing.

Asked by PeteBlackerThe3rd on 2019-08-13 06:47:31 UTC

Thanks PeteBlackerThe3rd so much for your feedback. 2 computers are connected by using Ethernet cable. The connection is well since I can subscribe and publish all of other topics. I use rospy.Subscriber to subscribe the topic /tf and /tf_static, and then use the function publish of rosbridge client to publish directly the data I subscribed from my computer (I also used this way to subscribe and publish other topics, all of them worked well. Only /tf_static of multicameras are lost data).

Asked by Getchbold NT on 2019-08-13 07:01:38 UTC

If both your computers are connected by an ethernet cable why are you using a multi-master setup? Would it not be much simpler to use a single master, then all topics would be available on both computers automatically.

Asked by PeteBlackerThe3rd on 2019-08-13 07:58:29 UTC

Thanks for your question. I have to use multi master since we would like to share topics for other computers also. We have some other computers in the network.

Asked by Getchbold NT on 2019-08-13 08:33:59 UTC

Just to clarify you do not need to use a multi-master setup to be able to share topics between different computers on a network. The most common ROS setup is to have a single master on a network and run nodes on several computers connected to that network, all sharing the same topics.

Multi-master setups are usually used when the network links between computers are very slow or intermittent.

Asked by PeteBlackerThe3rd on 2019-08-13 09:10:00 UTC

not at all, we use multi master is for some other reasons. However, my problem is not from multimaster. But it is from rosbridge and tf of multi cameras. It seems that I cannot get whole /tf_static of 3 cameras by using rospy.Subscriber

Asked by Getchbold NT on 2019-08-13 10:49:58 UTC

Can you explain exactly what you've tried so far, including source code. I also don't understand why you're using rosbridge if both networks are on the same LAN.

Asked by PeteBlackerThe3rd on 2019-08-13 11:17:59 UTC

Answers