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I wrote a basic node that reads an image from a local folder and publishes it. However, the topic is empty, i can not display the image when i use the image viewer. The cv2 image is being loaded correctly because i can display it with cv2.imshow function so the problem is the way i convert it to imgmsg.

I am not sure if this line works as it should:

image_message = self.bridge.cv2_to_imgmsg(cv_image, "passthrough")

The whole node is as simple as this:

class image_publisher:
 def __init__(self):
  self.image_pub = rospy.Publisher("image_topic",Image)
  cv_image = cv2.imread('/Pictures/image.png',0)
  self.bridge = CvBridge()
  image_message = self.bridge.cv2_to_imgmsg(cv_image, "passthrough")
  self.image_pub.publish(image_message)

How to pass a variable as an argument to ROS2 service? Hello everyone, I would like to know if it's possible to an add

Merging UR5e and Realsense URDFs after hand-in-eye calibration Hello everyone, I performed hand-in-eye calibration betwe

There is a python library called pyarmor which encrypts python files and packages. Although I am not sure how easy it is

UR in real life after Moveit Setup Assistant Hello all, I am trying to create my own custom application with UR5e + rob

Yes I saw that and that's great, but I meant creating a custom URDF for my own environment with table etc...

Hello all,

I feel a little bit confused regarding deciding what robotics stack to use for our application with universal robot (ur5e and ur10e) and where to start from.

ROS-industrial seems very well developed and maintained but it is based on ROS-Kinetic which was already EOL in April'21. I found out that there's a fork for ROS-noetic: https://github.com/fmauch/universal_r...

I also consider starting from ROS2, using the universal robot drivers here: https://github.com/UniversalRobots/Un...

However, if I didn't misunderstand, there are some useful features from moveit that are not ported to moveit2 yet, for example moveit setup assistant would be crucial for me since I want to merge urdf models to represent the real environment of the robot.

Also, ros2-galactic EOL is already November'22 and ros1-noetic is still supported until May'25 which I found confusing as well.

I would appreciate some feedback, Thanks in advance!

Thank you for both answers. I think it is a little bit more clearer now. I am familiar with ROS so I am not starting fro

Which ROS version makes sense for Universal Robot applications? Hello all, I feel a little bit confused regarding decid

Hi all, I am trying to create a custom environment for my UR5e robot and having a little bit of a problem understanding the file structure.

• I would like to have a fixed, not moving object around 1 meter away from the UR
• I want to see both the robot and my fixed object in Gazebo and RViz setups

So far, I have extracted the CAD model of my object in .stl format, and created a URDF file where I read that .stl file and I am able to spawn the object both in Gazebo and RViz.

My question is merging that URDF file with the UR setup.

Both xacro files here says that they should not be modified: https://github.com/fmauch/universal_r...

How can I merge them together with my new URDF file?

Where should I call that new xacro file? Here? https://github.com/fmauch/universal_r...

Is that correct/normal that the new object will be a part of robot_description or should I see robot_description and object_description separately? Since my object is not attached to the robot but rather something that should spawn in the environment, it didn't feel quite correct that it is a part of the robot_description.

I am using ROS Noetic with Ubuntu 20.04

Thank you in advance

Thank you for the answer. I am able to spawn the object in gazebo like this, however how do I also attach it to RViz and

Thank you for your explanation. What is the correct way of defining that .stl object so that it is visible in RViz and t

Universal Robot URDF and xacro structure Hi all, I am trying to create a custom environment for my UR5e robot and havin

Universal Robot URDF and xacro structure Hi all, I am trying to create a custom environment for my UR5e robot and havin

Hi, Have you found a solution to your problem? It would be great if you could update us. Thank you!

Hi, Have you found a solution to your problem? It would be great if you could update us. Thank you!

Hi all, I would like to know if I should avoid creating new variables in a callback function since the callback will be executed each time I receive new data, thus creating a new variable again and again. Thanks

Thank you for your answer Matthias. A follow up question to clear some of my hesitation, for the second use case exampl

Hi all,

I am currently working on navigation and I have a question regarding understanding a concept. From what I understood so far, global_costmap is created based on the pre-loaded static map by adding an inflation layer using robot footprint. So I assumed that the real time sensor readings from the robot such as laserscanners are only included in local_costmap. But the diagram on move_base page shows that LaserScan topic is used both in global and local costmaps. Could someone explain me how exactly are we using laser data in global_costmap?

Thanks in advance.

How are LaserScan and global_costmap related? Hi all, I am currently working on navigation and I have a question regard

Hi all, I am using turtlebot3 burger in which I'm using a rasp camera v2 attached to the Raspberry Pi with raspicam_node and a Host PC where I run my image processing nodes. Therefore, I need to transfer the captured raw images via wireless network. I am experimenting with different resolutions and frame rates at the moment to find out which is the most effective way. However, I have a doubt about the way I validate my results. I am using rostopic hz in my raspberry pi to find out the publishing rate of the camera, which is around 35-40 FPS for 1280x720 and doing the same thing in my local pc in which I get very different results like 1-2 hz to 10-15 hz. I know that this might be about the network but my question is, when I get 1-2 hz as a result of rostopic hz, I launch rqt_image_view and somehow the displayed capture does not look like 1-2 FPS but higher. So I am wondering if there is a better way to validate regarding the frame rate I receive from the subscriber, other than rostopic hz. Thanks in advance

That is indeed what I ended up doing yesterday, I think my hesitation was because I was not waiting a certain amount of