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Intermittent Communication Freeze in ROS2

Our team encountered a peculiar issue while developing with ROS2. We are using the iron version of ROS2, and during intensive communications between multiple nodes (short time intervals but not large ...
BobH233's user avatar
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1 answer
15 views

Multiple times same node and same topics

In ROS1 Noetic my students like to launch multiple times: the same node; the same topics. What is the exact effect of these multiple declarations ? For Node, is-it a problem ? When you create ...
goupil35000's user avatar
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What is the `Think in ros`?

Think in ros is the post I saw in the question here. It seemed like there was a discussion about why ros took this form. I'm writing this because I want to read a ...
ertretff's user avatar
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1 answer
88 views

Get robot position wrt world frame in ROS2-Gazebo Garden

I'm trying to understand how I can possibly get the global position of a model in a Gazebo simulation through ROS2. I've seen that Gazebo publishes data to the ...
slim71's user avatar
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0 answers
16 views

My ros topic can't echo any info

My code of node is following ...
young very's user avatar
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1 answer
200 views

How to get a topic name in a callback function (Python, Ros2)

I have two cameras subscribing camera1/image_raw and camera2/image_raw respectively. And both subscribers call image_callback when they received any topic. I want to show camera1 image in window1 and ...
suhjw2762's user avatar
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0 answers
36 views

Does rclpy supports intraprocess communication?

I wanted to know if rclpy supports intraprocess communication or is there a way to do intraprocess in rclpy with python based libraries? Thanks,
Kirito's user avatar
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ROS2: RQT can not get message class for a user defined message

I can build a package used to define interfaces like messages, service and actions. I think everything is fine since I can show them using the usual command ...
Antonio Bono's user avatar
1 vote
3 answers
276 views

ROS2 data exchange over network

I have a question regarding ROS2 data exchange over the network. Let’s assume, I have two hosts that are running some ros nodes over the same network, using ROS_DOMAIN_ID=0, so I broadcast all topics. ...
Filippo Bentivoglio's user avatar
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1 answer
94 views

no new messages for rostopic hz /camera/aligned_depth_to_color/image_raw in ros noetic inside docker

steps to reproduce the problem In the first terminal type: ...
Mona Jalal's user avatar
0 votes
1 answer
81 views

Ros2, topics still persist after subscribers/publishers go out of scope

I have a map plugin I've made for rqt_gui that I am going to be using to visualize location information from n number of ROVs/autonomous vehicles. So far I am able to find and create subscribers to ...
supermepsipax's user avatar
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0 answers
42 views

VRX wamv position using ROS2

I need information about the instant position of the wamv (osrf/vrx). Using ROS1 + Gazebo11 it works in general properly: ...
sendilkelm's user avatar
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0 answers
84 views

Communication problem of ros2 humble

On the ROS2 humble version, we publish messages using the topic method, and there is a probability that the node subscribing to the topic will not receive the message. This situation usually occurs ...
prince_magic's user avatar
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0 answers
51 views

navsat_transform_node imu topic data mapping problem

I ran into the problem of mapping the /imu/data topic of the navsat_transform_node node in the robot_localization package. the node has a very strange behavior - when mapping imu data to the /...
5met4nka's user avatar
0 votes
1 answer
246 views

ros2 topic list doesn't work in sudo mode

Hi all, I'm using Ubuntu 22.04.1 LTS with Linux 5.10.0-18-rt-amd64, with ros2 humble debian release. I try to launch ros2_control from sudo terminal, but I can't see the ros2 topics outside ( from ...
user avatar
0 votes
1 answer
98 views

Processing pointcloud2 using ros node with both publisher and subscriber

I am trying to process a pointcloud2 being generated by the /map topic, which I play from a rosbag file containing the topics /tf, /map, /ssl_slam/trajectory topics. By process, I mean I want to ...
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0 votes
1 answer
58 views

Subscribing and publishing to the same topic (/map) in a single python ros node

My goal is to process a PointCloud2 and visualize it in RViz. I have rosbag data collected. This rosbag file includes /map, /tf, /ssl_slam/trajectory topics. The /map topic is in the form of ...
user avatar
0 votes
1 answer
92 views

[ROS2 Foxy] Topics sometimes subscribed to and sometimes published to

I have two Nodes who communicate with a Float32 message topic. The typical sequence of events are: Node A starts Node B starts Node A waits to subscribe to topic T Node B creates topic T publisher ...
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1 answer
11 views

ROS2 topic name validation

Is there a way to validate topic names in rclcpp? For ROS1 I was using the validate function defined here. Is there anything that is equivalent in C++ for ROS2? ...
user avatar
0 votes
1 answer
448 views

ROS2 nodes stay alive and keep publishing after shutting down

Hi, I am currently working with ROS2 Galactic on Ubuntu 20.04.3 LTS (Focal Fossa) on a project of mine. The problem: After stopping my launch file and shutting down my computer, the next time I open ...
user avatar
0 votes
1 answer
40 views

ros2 topic pub from launch file

Hello everyone, Does anyone know if it is possible in ros2 to directly start from launch file a simple node that publishes a message? In ROS1 it was easily possible like this: ...
user avatar
0 votes
1 answer
74 views

ROS2 Resolve topic names rclcpp

In ros1 cpp I was able to resolve a string containing the topic name to the actual topic name that accounts for remappings using the following block: ...
user avatar
0 votes
3 answers
146 views

How to show topics using python in ROS2

Hi, everyone. Like the title, I want to show topics using python in ROS2. First I thought use a ros2 topic list command through a ...
user avatar
0 votes
1 answer
9 views

how can i save rostopic in array?

Hi guys. I need help. I want to make nodes that 'subscribe topic - save in array' and 'read array - publish topic'. (in my case it is geometry_msgs::Pointstamped) But there are no references and ...
user avatar
0 votes
2 answers
41 views

trajectory_msgs/JointTrajectory Exception :AttributeError: 'str' object has no attribute 'positions'

I wrote a python script to publish a JointTrajectory message. It results in an Exception: AttributeError: 'str' object has no attribute 'positions'. The python script: ...
user avatar
0 votes
1 answer
32 views

Read /rosout/msg with seperate Python script

Hello! I am currently working on a project where I navigate a TurtleBot3 to several positions in a room. The TB3 navigation is triggered by publishing messages to a specific topic (/tb3_hsc/command). ...
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0 votes
1 answer
3 views

Does ROS2 support keyed topic?

Hi everyone, As stated in the title, does ROS2 have topic with keys? I have been studying ROS2 for few weeks and I have looked around but cannot find anywhere stating about keyed topic in ROS2. Maybe ...
user avatar
0 votes
1 answer
4 views

How can I round /scan topic values?

Hello! I am student and I really want to send /scan topic values to rtabmapviz. I am using ROS kinetic, /scan is topic created by RPLidarNode. Unfortunately I think that I need rounded values, because ...
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0 votes
2 answers
2 views

When exactly is a connect callback of a publisher called?

Hi all, I would like to know when precisely the connect_cb is being invoked, specified in ...
user avatar
0 votes
1 answer
6 views

Number of TCP connections for a "bidirectional" topic?

Hi all, I have a (possibly) simple question: assume if I have two nodes A, B that communicate over a topic "/my_topic", i.e., both nodes subscribe and publish to "/my_topic" using ...
user avatar
0 votes
1 answer
15 views

In publish raise ROSSerializationException(str(e))

In my package that I created, there are 3 nodes currently. I also generate a custom message which is "AnchorScan". First node does some stuff and only publishes from ...
user avatar
0 votes
1 answer
2 views

What is the proper convention for published topic names?

Hi, I'm working on a wheeled robot using rosserial and I am publishing wheel encoder counts and velocities. I was wondering if there was a proper way to write the topic names I am publishing. For ...
user avatar
0 votes
1 answer
7 views

How to subcribe both Image topic and Text topic in the same time?

Hi buddy, I am newbie in ROS. And this is the first time i'm trying to subcribe 2 topics type, 1 for Image topic and 1 for Array of ints topic. And i have a problem on it. This is my source code: <...
user avatar
0 votes
1 answer
31 views

How to send Array Message from Arduino to ROS Topic?

Hi Buddy, I'm newbie in ROS and i trying to send data from arduino to Ros Topic. I have send string and integer type. But in Array type i have a small problem. This is my source code: ...
user avatar
0 votes
3 answers
5 views

How to subcribe 2 image topics with 1 node in same time?

Hi buddy, My name is Toan. I am a newbie in ROS. Now, i'm using Kinect Camera and trying to subcribe 2 image topics with 1 node. But seem like my code is wrong something. If i try to subcribe 1 node ...
user avatar
0 votes
1 answer
1 view

how to calculate difference of two messages in callback function on same topic

Hi Sir, I am actually reading my hand pose from a Leap Motion sensor and I want to calculate how much the hand moves in X direction. My question is how to read the message in callback function(as you ...
user avatar
0 votes
2 answers
6 views

How to create a node to share data between different robots

I am trying to build a data structure (cloud system) able to receive and send data and instructions from/to different kind of robots (e.g. drones,turtlebots). My idea is to create a node to which ...
user avatar
0 votes
1 answer
18 views

How to wait a method until a callback finishes?

Hi all, I'm trying to stop a method until a particular callback is executed, because this method uses data that is updated in the callback, but I don't know how to do this task. I'm using ros kinetic ...
user avatar
0 votes
2 answers
7 views

How many nodes can publish to a single topic?

hello every body. I'm new in Ros and I have a simple question. How many nodes can publish to a single topic? thank you. Originally posted by hamed ghasemi on ROS Answers with karma: 3 on 2018-10-07 ...
user avatar
1 vote
2 answers
67 views

[ROS2] Retrieving QOS settings for a topic

Hi, since a subscriber can receive a topic message only if its QOS profile is compatible with the QOS profile of the publisher, is there a way to retrieve the DURABILITY and the RELIABILITY settings ...
Myzhar's user avatar
  • 198
0 votes
1 answer
12 views

Message order with multiple publishers to same latched topic

Scenario: a node A publishes "hello" to a latched topic /x with queue size 1 then a node B publishes "world" to the same latched topic /x with queue size 1 Because of the latched ...
user avatar
0 votes
1 answer
18 views

How to check size of a topic on multi device ROS Communication

Hello, experts. I am trying to ROS communicate with multi device. There is two PC. First one have a camera sensor, it have publish topics by 30 fps. Second one have be connected to another by 1Gb ...
user avatar
0 votes
1 answer
4 views

Undefined reference to RosIntrospection functions

Hey guys, I try to convert the Raw Buffer of a ShapeShifter to its original DataType Structure. But I have Problems understanding the new API. In the wiki the author used functions, which are not ...
user avatar
0 votes
1 answer
3 views

hz of our sensor's the topic was DECREASED, When I record some data with rosbag

Hello, experts. I used rosbag to acquire our sensor data as camera, lidar. You can reference below spec. Camera Node : 1980x1208 (FHD, RGB), 20 hz Lidar Node : 64 Channel, 20 hz I recorded topics on ...
user avatar
0 votes
1 answer
11 views

How to increase frequency of /diagnostics topic published by epos_hardware node?

Dear ROS community, I am using the epos_hardware ROS package as a hardware interface between an effort controller and a EPOS2 motor controller coupled with a Maxon EC90 motor. The set up is working ...
user avatar
0 votes
1 answer
8 views

Fanuc Robot: Get ROS to read I/O pins

More of a general question, but has anyone figured out how to get a readout of any of the digital pins I/O within ros, as some form of a publisher? Originally posted by nquattro on ROS Answers with ...
user avatar
0 votes
2 answers
21 views

FastRTPS Topic & ROS2 Topic list

Hi, All. When using the HelloWorld example of the C++ example in ROS2, it appears in the node list, but not in the topic list. Of course, when node_demos_cpp is used, it appears in the Topic list. But ...
user avatar
0 votes
1 answer
2 views

Why do I get ampersand characters in my strings?

I'm trying to fix an issue that appeared on ROS Melodic, I cannot reproduce this on ROS Kinetic. In short I'm using QCheckBox objects and setting the text to a ROS ...
user avatar
0 votes
1 answer
4 views

It was delayed to subscribe a image topic by frame rate of Images

Hello, guys. I have used ROS Kinetic on ubuntu 16.04. I make a two node. The one is publisher node to publish image topic. Another is subscriber node to subscribe publisher's topic. The transmission ...
user avatar
0 votes
1 answer
14 views

rosbag : rewrite the values of a topic

Dear all, what can be the best way to rewrite the values of the messages in a topic in a bag file. For instance, how can I go about creating a new bag that contains modified values of a topic of ...
user avatar

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