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Running ROS Noetic. I am receiving the following error on transforms published by UKF node from robot localization:

Warning: TF_REPEATED_DATA ignoring data with redundant timestamp for frame base_link at time 1597872121.936377 according to authority /ukf

I see this error popping up wherever the transform is being used (e.g., rviz) as well as in the UKF node's console output.

I did not have this issue with a hand-coded transform node. I am a bit uncertain how the UKF node handles and publishes transforms internally so hard for me to think about what could be causing this, here is what i know:

• Timestamps on incoming odometry (only source I am using right now for testing) are being set correctly
• Does not occur with any other transforms published by other nodes
• We have multiple developers working on multiple different PCs, Some are VMs, some are physical installations. The error occurs repeatably on all of them so I don't believe it is any sort of system clock error or similar

Sorry for lack of additional detail, not sure what will be most helpful to share. Please let me know and I will update post.

TF_REPEATED_DATA error with robot_localization ukf package Running ROS Noetic. I am receiving the following error on tra

Fresh Ros Kinetic install on Ubuntu 16.04 (installed today). Try to launch RVIZ and get this error:

rviz: symbol lookup error: /opt/ros/kinetic/lib/librviz.so: undefined symbol:
_ZNK9QTreeView16viewportSizeHintEv

Things i've tried (that have not worked):

• Rebooting
• sudo apt dist-upgrade
• googling this problem
• Deleting, and remaking my catkin workspace.

Possibly relevant info:

This is a pretty standard installation of Ubuntu + ROS and the system install is pretty fresh as well. Only non-standard stuff I've done so far is I've installed nVidia video drivers to make a 1080 TI video card work and I've updated the kernel to version 4.15.2 to resolve a system clock drift issue with i9 processors.

Problem solved. Turned out that rviz was grabbing the wrong QT dependencies from an unrelated program installed on the c

Problem solved. Turned out that rviz was grabbing the wrong QT dependencies from an unrelated program installed on the c

Problem solved. Turned out that rviz was grabbing the wrong QT dependencies from an unrelated program installed on the c

QT 4.8.7 and qt 5.5.1 are installed. Running with default configuration makes no difference, identical error (Since this

QT 4.8.7 is installed according to "qmake --version". Running with default configuration makes no difference, identical

rviz: symbol lookup error Fresh Ros Kinetic install on Ubuntu 16.04 (installed today) Try to launch RVIZ and get this e

rviz: symbol lookup error Fresh Ros Kinetic install on Ubuntu 16.04 (installed today) Try to launch RVIZ and get this e

rviz: symbol lookup error Fresh Ros Kinetic install on Ubuntu 16.04 (installed today) Try to launch RVIZ and get this e

ROS: groovy OS: ubuntu 12.04

What we are trying to do is have roscore start upon boot (have this working now) and then execute a launch file. I am not a linux person, so I feel I am really not approaching this the right way. Currently, this is what I have attempted:

1) roscore is launched via a script in /etc/init.d. This is fine. 2) I want to launch my launch file on boot. Manually, I do it like this: roslaunch rover.launch. It works great. 3) I would like this to start on boot, so I tried the following: inside new script (boot.sh) - note i disabled password prompt for sudo:

 sudo su - roboops
 /home/roboops/groovycat/scripts/bootRoverLaunch.sh

bootRoverLaunch.sh:

cd /home/roboops/groovycat/
source devel/setup.sh
sleep 5
roslaunch rover.launch > /home/roboops/groovycat/scripts/startup.log

4) I went to "startup applications" and added "bash /home/roboops/groovycat/scripts/boot.sh"

5) Tried rebooting. Roscore starts, and the launch files executes. However, the nodes malfunction and don't work correctly (They work fine when started using the launch file directly in a terminal window. Oddly, it also works fine if I log out and back in once)

More specifically, here is the problem when using the above script to launch:

I am trying to run two nodes:

-joystick node (publishes joy topic) -motor control node (listens to joy topic and outputs commands to motor controllers via serial)

Joystick node starts successfully and If I do rostopic echo joy, I can see the values. Motor control node is listed as running but if I run roswtf it says:

Found 3 error(s).

ERROR Could not contact the following nodes:
 * /Drivetrain

ERROR The following nodes should be connected but aren't:
 * /Drivetrain->/rosout (/rosout)

ERROR Errors connecting to the following services:
 * service [/Drivetrain/get_loggers] appears to be malfunctioning: Unable to communicate with service [/Drivetrain/get_loggers], address [rosrpc://Rover:58631]
 * service [/Drivetrain/set_logger_level] appears to be malfunctioning: Unable to communicate with service [/Drivetrain/set_logger_level], address [rosrpc://Rover:58631]

The idea is, I need everything to automatically start on power-up. There will be no input devices/monitor connected to it when it is in use.

I'm having trouble with RVIZ being unable to show laser scan point data. I'm not sure if this is an RVIZ problem, a problem in my RVIZ config, or a problem with my setup in general (ie: i'm doing something bad with coordinate frames or something along those lines).

Background: I am new to using tf frames within ROS. I decided to learn how to use tf and frame headers to properly tag all my sensor data so I can use provided packages (like for example hector_mapping). I'm going to try and give background to how I arrived at where I am now in case the context helps because I'm really not sure what I did to break it.

Here's how I used to be able to see my laser scan data (it is from a little neato lidar):

1. open rviz
2. add LaserScan
3. Set topic to neato_scan topic

Next I created a node which transforms my neato_laser frame to base_link, and then configured hector_mapping and launched it. It worked well and I was able to visualize both the map and laser scan data after configuring rivz.

At some point (the problem is I'm not sure exactly what changes I made to trigger, if any) RVIZ stopped showing laser scan data.

Here is what I know:

• Hector_mapping is still able to see and transform the laser_scan data correctly. The map generates fine and the robot is able to localize from the laser data + map. To me this indicates the coordinate frame transforms are infact setup correctly.
• I am able to verify there is scan data being generated by doing rostopic echo /neato_scan
• In RVIZ, no matter what I try, I can't get it to visualize the laser scan data.

I've tried with the full config that allowed me to see the map + laser scan data before, and I've also tried reverting to setting all frames (fixed frame, target frame, etc) to neato_laser and only adding the LaserScan to the visualization.

Present Situation:

• LaserScan shows status "OK" and under topic it shows xxx messages received which counts up correctly.
• Occasionally a single point will show up for a split second, usually at the origin. If i place a large decay time, it will show several points, mostly at the origin, and some at impossible locations (for example in mid air directly above the origin)
• There is no evidence of any errors. All of RVIZ status fields show OK with green check mark.

ITs quite likely I'll need to provide more info/do some debugging to trace this problem but I'm not sure how to proceed. Any help in how to sort this out is much appreciated.

so I went ahead and restarted the computer for the first time in a couple weeks and the problem resolved itself.

Not only is the point cloud being rendered correctly now, but also things that were missing before that I didn't notice (such as labels on tf transforms) have popped up as well.

I'm working on a multi-robot system. Currently, the system runs one roscore on a "mission control" machine. Each robot runs all of its own nodes on its own machine. Bandwidth between machines is limited and latency is variable (the system uses wifi and also 4G + VPN).

The general model here is that data exchange between machines is very minimal and relatively infrequent. Any cross-machine message should not be time-critical or require high bandwidth.

I am new to TF and I want to understand how it exchanges information. For regular ros nodes, the mapping between the networking layer and the ros layer is very straightforward. A ros pub and subscriber represents a TCP/IP connection. IF the pub and sub are on the same machine, then there is no network traffic.

I am having trouble understanding how tf exchanges information over the network. The descriptions I've found are a bit vague and according to the ros node graph (using rqt_graph), it seems everything just goes to a node called "/tf".

What I would like to accomplish is this:

• Each robot has its own set of local frames, updated continuously, which I would like to avoid transmitting over the network.
• The "mission control" machine maintains a global world frame, and knows where each robot is located (but this can be updated on the order of 1hz or less).

If someone could provide me with some reference info that will help me design this, it would be much appreciated.

What I'm hoping I can do is follow a model similar to the rest of the nodes:

• Make sure tf frames are only accessed on the machine they are generated on.
• Write a slow-update node that simply publishes the robot's position to the "mission control" node at a low rate. My hope is this prevents tf from sending data over the network.

I am trying have two computers communicate over a network as described here: wiki.ros.org/ROS/NetworkSetup

The problem is, no matter what I do, it seems that ros tries to communicate using hostnames. I want to use IP addresses only.

on both computers I have tried setting both ROS_IP and ROS_HOSTNAME to their own respective IP addresses.

-Both computers are able to ping eachother

• ROS_MASTER_URI is set to http:// master.IP.Add.ress:11311 on both computers

• upon running rospy_tutorials talker.py on the "other" computer, it shows up under node list on the "host" computer. However, if I run rosnode info on the talker, it says:

  contacting node http:// ubuntu:33802/ ...
  ERROR: Communication with node[http://ubuntu:33802/] failed!
  

Running the listener, or rostopic echo on the talker yields no results. Why can't I get rid of the "ubuntu" hostname? I just want IP addresses.