[ROS Tutorial] ROS Control 101 + connect Gazebo simulated robot

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Recommends R. Tellez · 2017-09 · Robotics Stack Exchange · on “How to implement ROS in my custom made robot?”

When you have a new robot, you will need to ROSify that robot. What does it mean? You will have to build a series of nodes (among other things) that make the translation between your hardware and the ROS core. Some basic steps to start: You should write the URDF of your robot that describes the different links in your robot, joints and sensors, and different frames that it has. You will need that in order to represent your robot in Rviz, show the robot current status and be able to compute sensor data from different frames. If you don't know how to do the URDF of your robot, you can check this tutorial [LINK] . Next thing is to write some nodes to read the sensor data and publish it in ROS t

Recommends R. Tellez · 2017-11 · Robotics Stack Exchange · on “Moving Joints in Gazebo simple example?”

Hi, first, in order to move your robot joints you can use Gazebo or ROS. I recommend to use ROS because it is very well integrated, several controllers already provided, and it is a lot easier. However, if you want to learn how to do it with Gazebo itself, have a look at this git [LINK] . If you want to control the robot with ROS, then you need to do first a translation of your model to URDF. Sorry SDF does not work with ROS, specially if you want to show the robot in Rviz. So, go for the translation of format. To do a translation from SDF to URDF watch this video [LINK] . So now I will assume that you have a robot model in URDF which includes some joints. In order to keep the discussion sou

Recommends lotfishtaine · 2019-12 · Robotics Stack Exchange · on “How to control a rotating joint in velocity”

1- the yaml file is basically describe the used controllers. It always contains the joint_state_controller which is in charge of providing constant information about the state of the joint, and the description of the other controllers. The /joint_states topic is published by an instance of the JointStateController . This is a read-only controller that does not command any joint, but rather publishes the current joint states at a configurable frequency ( publish_rate ). 2- the inputs to ros controllers are always in SI units, so a joint velocity controller will accept radians per second. 3- joint_state_controller : it continuously provides the state of the joint. 4- for the question in the co

Cites juanlu · 2017-08 · Robotics Stack Exchange · on “Trouble understanding ROS Control”

Hi, I am trying to enable a Mecanum Wheeled Robot [LINK] in ROS Control and I am having a lot of trouble understanding what it is that I have to do. From what I understand the data flow is as such: I'm using the Ridgeback mecanum controller [LINK] and through arduino I have access to the wheels velocities. I have read the ros control documentation and seen the 2014 ROSCon video about ROS Control but I'm still missing that last piece to understand it. Cheers! Originally posted [LINK] by juanlu [LINK] on ROS Answers with karma: 189 on 2017-08-22 Post score: 0 Original comments Comment by lucasw [LINK] on 2017-08-22 : Is it the hardware interface you are missing? You can launch the mecanum cont