ROS Q&A | Why print works but rospy.loginfo doesn’t?

When we are developing ROS Programs, it’s common to use “print” or “rospy.loginfo” to print some text on the screen in order to see if our program is working as expected.

The problem is that sometimes the “rospy.loginfo” doesn’t work and we have no idea why it happens.

In this video we show how to make the rospy.loginfo shows the texts on the screen, by answering a real question asked on ROS Answers.

If you want to see the question and get the code used on the video, you can find it on the following link:

https://answers.ros.org/question/268370/print-works-but-rospyloginfo-doesnt/

ROS Q&A | How to create and spawn humans in Gazebo7

Here you have a fast tutorial for creating your own human models in a format that can be spawned in Gazebo7 without any problems.

You will use makehuman software and ROS Development Studio for showing all this.

If you are interested in any element of the video to be explained in extra videos please leave a comment telling us what you would like to be explained in more detail.

ROS Q&A | How to deal with transmission tags for gazebo ROS control

This video shows how to properly update the transmission tags in your URDF file in order to work properly with the Gazebo ROS control plugin.

ROS Q&A | Create an obstacle that cannot be stepped in for Gazebo Simulator

Let’s learn how to create an obstacle in Gazebo. Here you have the video response of how to do this test:

Here I leave the main things I used to test it and some system information:
Information System:
Ubuntu 14.04.5 trusty ROS Version: indigo Gazebo 7.4.0

I Created a Gazebo model with the code you posted: C:\fakepath\model.sdf And a “model.config”

Then I spawned it in a empty world: C:\fakepath\model.world

And then I used a simple spawn launch for sdfs: C:\fakepath\spawn_testobject_sdf.launchC:\fakepath\spawn_sdf.launch

I then used one robot I had to test the interaction, and it intercated perfectly, it didn’t go through.

We need more info to get to the solution but, definetly is not the box. The problem may come from some world parameters, or from the robot itself. Maybe the meshes of the feet are to simple or don’t have enough subdivisions in the mesh. Maybe its ultra heavy or maybe its something configured that avouds colisions with certain elements.

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Answer response to the gazeboanswer question:
http://answers.gazebosim.org/question…

ROS Q&A | How to create an actuated Hexapod with PID in Gazebo? (Video)

I know this is an old question but I think even now because knowing how to create an hexapod with plugin that moves the robot around and with an SDF model not a URDF might be useful to someone.

Check this video answer which explaining a bit the process and the result:

So I there wasn’t anything wrong with the model. It must have been something related to the plugin or some strange library error.

I essentially created a gazebo plugin that moves the joints using SetPosition and PIDs and it works just fine. I’m posting here the code I can.

Hope this is useful for you. 

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Answeing the question made in GAzeboAnswers:
http://answers.gazebosim.org/question/12044/hexapod-simulation-not-working/

Here you have some sources used for this micro tutorial:
http://gazebosim.org/tutorials?cat=guided_i&tut=guided_i1
http://osrf-distributions.s3.amazonaws.com/gazebo/api/dev/classgazebo_1_1physics_1_1JointController.html