Questions tagged [synchronization]

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[slam_toolbox]: Failed to compute odom pose

I'm trying to run my simple robot in the Flatland simulator, ROS2 Humble. The problem occurs when I try to execute the command ...
Tomas Novotny's user avatar
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ROS2: How to synchronize two topics with message_filters and a defined QoS

I try to synchronize two ROS2 topic using message_filter (sync_policies/approximate_time): a sensor_msgs::msgs::Imu from an Imu a sensor_msgs::msgs::PointCloud2 from a radar, which is published with ...
Florian Martin's user avatar
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how to pass data to two different nodes exact same

Hi, I am working on a project to command six motors around same time. Due to my project requirement, I have created two different nodes to command 3 motors on each node. But, I am wondering how can I ...
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2 answers
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publish after processing data from 2 synced subscribers (rospy)

I want to make one node to subscribe 2 topics synchronously, process those data, and publish it. I know that publishing and subscribing data with single node is possible, but have never seen any ...
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Inconsistent time discrepancy synchronize

I'm trying to make a node which subscribes both rgb image and point cloud from asus xtion pro live. It seems like there is inconsistent time discrepancy between these two and synchronizing does not ...
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2 answers
18 views

How important it is to sync the timing for gnss and lidar in localization?

I have not synced the timing for gnss and lidar yet. Will it affect the localization accuracy a lot? I found gnss_pose is published based on the GPS time and ndt_pose is published based on the current ...
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1 answer
11 views

Questions regarding ROS time synchronization

Hi all, MY question is related to here. We have a remote PC, local PC and a jetson running at the same time. I was told that ROS time synchronization is important in this situation. My question is ...
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1 answer
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How to use chrony for two ROS masters on one computer?

I am running two ROS masters on one computer and I'm using the Multimaster FKIE package to connect the two ROS masters. I think I need to synchronize the time of both ROS masters to make my scenario ...
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1 answer
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can't synchronize Velodyne points with other PointCloud2 data

Hi, I am new to ROS and I need a help for time synchronization. When I synchronize Velodyne points with ZED Images, they are synchronized without any problem (I attached this working code below). But, ...
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1 answer
15 views

How can I subscribe to 2 different topics in a synchronised manner in ROS2?

I have 3 different nodes : Node2 subscribes to two different topics of same types published by node 1 and node3. Then it does some calculations on these subscribed topics and the publishes to a new ...
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1 answer
7 views

How to troubleshoot: protocol synchronization is lost

Suddenly I start seeing this error: [ERROR] [1520525542.826204079] [/rosout]: a message of over a gigabyte was predicted in tcpros. that seems highly unlikely, so I'll assume protocol synchronization ...
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How to create disparity images with ueye_cam and nodelets

Hi there, I'm currently trying to get a disparity image out of a pair of externally triggered UEye cameras from IDS. I'm using nodelets instead of nodes to avoid overhead and desynchronization caused ...
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Is it possible to receive a msg on a certain topic by calling a service?

Hi all, I'm working with gazebo, where I created an indoor environment and a mobile robot. The robot is equipped with an RGB-D camera and a logical_camera. Now, I would like to write a node that, ...
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1 answer
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[Solved] C++: ApproximateTime with more than two topics?

Hi @all, short version: Could you please provide me with a full version for synchronizing up to eight image topics with ROS? long version: I am currently trying to get my Synchronizer to work. Thanks ...
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synchronization of two image topics (infrared stream)

Hi all, I would like to sync the left and right infrared image topic from my Intel RealSense R200 camera. Currently, I have managed to subscribe to the individual infrared topic (left and right) with ...
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1 answer
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How to synchronize a ROS publisher node with gazebo simulation time?

Hi everybody I have an offline trajectory generation program which is written in MATLAB that produce joint trajectories for my humanoid robot. I saved the trajectory in a text file and load it through ...
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1 answer
9 views

While using message_filters to do the time synchronization,but it cannot enter into the callback function

I am using sync_policies::ApproximateTime in message_filter to do the PointCloud2 and LaserScan time synchronization, but the problem is it cannot enter into the callback function of...
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1 answer
5 views

Synchronisation with Subscribers

I would like to have two subscribers in one file. Two subscribers are supposed to subscribe to two different topics, get their respective data and process them. In order to get this working, I need ...
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1 answer
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why RGB and depth Image synchronization not working? [Solved]

why this works ? but not the bottom one? ...
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1 answer
4 views

Dynamic_reconfigure's .cfg file synchronization with parameter's changes

Hello folks! I'm wondering is there a simple way to update your .cfg file (used by dynamic_reconfigure tool) with the changes you make during program run? So that each time you restart roscore, the ...
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1 answer
27 views

Data in Rviz not synchronized

Hello, I have some problems of synchronizations. I publish stereo pictures from my dataset (left and right) then i get the disparity and the depth map. Despite the parameters , i have a shift of ...
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1 answer
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Error using sensor_msgs global variable

Hi everyone, When trying to use global variables of type sensor_msgs I'm getting some errors running the code (compilation is done without errors), and I don't know what it referes. I declared the ...
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1 answer
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Ros messages needed at different frequencies by two diff applications

Hi need a help Suppose I have a message that publishes on a topic at a regular frequency. Two more applications (not necessary ros nodes) wants the messages but at different frequencies. For ex at 2 ...
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1 answer
16 views

rosbag topics out of order

Indigo, Linux Mint 17 I'm using the commandline rosbag utility to record various topics. I have two topics /topic1 and /topic2. Topic1 is published before Topic2, like so: ...
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3 answers
3 views

Two Subscriptions synchronization

I'm subscribing to two cameras (as stereo system) with different FPS using one node. How can I make sure that after few minutes, I'm taking the same images of the world with the two cameras like there ...
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1 answer
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Problem running ApproximateTime Policy tutorial

I'm trying to make use of the an ApproximateTime synchronization, however I am having a boost library related issue with that. Then I decided to test the actual ros tutorial here. Here is the source ...
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1 answer
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synch problem with chrony and xenomai

Hi all, I've just discovered that to synchronize messages across different physical machines I have to use Chrony. Everithing is fine....except when I actually run my real robot, which is actuated ...
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3 answers
9 views

Synch problem with rosbag and rqt_plot

Hi All, I'm building a pose estimator and to assess it i'm using a ground truth from a vicon system. Both systems publish a PoseStamped message. When I ...
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1 answer
5 views

Synchronize headerless messages

Hi, I want to synchronize messages without headers. I know synchronization can be done with message_filters when they have timestamps, but these messages are the ...
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0 votes
1 answer
7 views

ros subscribe to the latest available message

I am using rospy but I don't mind getting a solution in roscpp. I have a publisher that publish message at a rate of 60Hz, and let say my subscriber is capable of handling messages at 6Hz. I am ...
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2 answers
1 view

How to implement offline data synchronization on several nodes?

Hi, I asked a first question here http://answers.ros.org/question/122901/how-to-implement-offline-data-synchronization/?answer=123036#post-id-123036 but I did not have the right answer of my ...
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2 answers
7 views

How to implement offline data synchronization?

Currently I work a lot with ROS and I think, this middleware, provides a good way to produce loosely coupled modules and a very easy way to use frames transformations. But I have a serious issue and I ...
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0 votes
1 answer
9 views

timing problem with laser scan (synchronizing with odometry)

Hi guys, I've got a timing problem with my laser scans. I receive laser scan data through a tcp socket (it's simulated laser data from another system in the network). While the robot is standing still ...
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0 votes
1 answer
11 views

sync problem on image and camera_info over wireless

I was running pgr_camera_driver (with a PointGrey Flea3 GigE camera) that published both color image and camera_info with the same timestamp in tandam over wireless network. Color image and ...
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1 answer
2 views

Is sensor timestamp can modify robot_pose_ekf accuracy?

Hello, I'm using a visual odometry working on a workstation connected by wifi to the Turtlebot. I have synchronized the time in the workstation related to the turtlebot with: sudo ntpdate tutlebot_IP ...
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1 answer
42 views

Using Approximate Time Sync - how does it work?

Greetings, take this for instance: ...
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3 answers
3 views

Synchronizing multiple robots from 1 machine and 1 ros master

Hey, Are there any tips or common practice how to synchronize 2 or more robots to do the same "move". Example: when all robots are started up and waiting, both go forward for 10 seconds, ...
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0 votes
1 answer
14 views

synchronizing two point grey USB cameras for Stereo using OpenCV?

Hi, I have two Firefly MV USB cameras from PoinGrey which are working with the Camera1394 node, Im able to view the images and create an package containing c++ code which uses the cv_bridge node to ...
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0 votes
1 answer
3 views

Synchronizing messages without time headers

Hi all, I am trying to synchronize subscription from a few topics from custom messages. armj_cmd_pos_sub = message_filters.Subscriber("/arm_controller/position_command", JointPositions) ...
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1 answer
2 views

How to test whether stereo cameras is synchronization?

I made a stereo camera consist of two digital cameras. I want to test whether the left and the right images is synchronization. Are there some tools or nodes which have this function? (PS:I can get ...
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0 votes
1 answer
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Control Loop and Communication Loop Synchronization (sep. nodes)

Hello, everyone, My goal: I would like to find a standard way to allow control loops to be developed separately from the CAN communication. This would allow for easy interfacing with the hand without ...
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1 answer
1 view

libboost error during linking

...
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1 answer
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Non-synchronized nodes in different machines. What to do?

I have two different machines connected by wifi sharing a ROS_MASTER. One of them is the erratic robot which is sending odom messages continuously. The point is that those messages are being received ...
Pablo Iñigo Blasco's user avatar
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1 answer
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Is rxplot time-synchronized?

I'm monitoring a couple of message fields which come from different topics located in different machines. The question is if rxplot considers those messages having an stamp to paint the data. If not, ...
Pablo Iñigo Blasco's user avatar
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1 answer
5 views

rosbag play on two machines

Hi, I have recorded simultaneously multiple cameras sequences on two machines with rosbag. I now would like to replay this sequence simulataneously on the two machines (to avoid transfer images on the ...
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0 votes
3 answers
37 views

image_raw and camera_info not synchronized in Wlan

Hi, I am trying to send compressed depthimages over "/camera/depth/image_raw" topic using image_transport on Wlan. But even compressed they seem to be too big for the Wlan. The program ...
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0 votes
1 answer
2 views

callback for two topics at the same time

Hi everyone, I would like to save an image from a depthcamera and a webcam at the same time as a mouse click. So I subscribed to the depth image and in this callback I used ...
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0 votes
1 answer
3 views

rospy: Approximate sync

Is there an approximate synchronisation in rospy? I can't found anything in the documentation. Only here http://www.ros.org/wiki/message_filters section 8.1 speaks about python but it seems as copy ...
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2 answers
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Time Synchronizer hangs after few messages

enter code hereHi, I have a scenario where I have 2 sensors publishing messages to 2 different topics, let's say: topicA topicB I wanted to subscribe to both these ...
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1 answer
4 views

Time Synchronizer with more than 9 incoming channels

Hi, I need to synchronize 32 image topics, which then trigger one common callback function. Unfortunately message_filters::TimeSynchronizer only supports up to 9 topics, and so does message_filters::...
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