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ROS: Difference between revisions

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(Created page with "[http://wiki.ros.org/Documentation ROS] is a software platform for robotics. ==Concepts== * [http://wiki.ros.org/Topics Topic]: a named bus on which messages of a single type...")
 
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** msg/MyMessageType.msg defines messages for the package, published to topics
** msg/MyMessageType.msg defines messages for the package, published to topics
** srv/MyServiceType.srv defines services for the package, supporting request/reply semnatics
** srv/MyServiceType.srv defines services for the package, supporting request/reply semnatics
* [http://wiki.ros.org/Nodes Node]: a named process that performs computation
** A running node has a type and a graph resource name
** A node is typically launched standalone using [http://wiki.ros.org/rosbash#rosrun rosrun]
* [http://wiki.ros.org/Master Master]: implemented by the [http://wiki.ros.org/rosmaster rosmaster] package, usually started via <code>roscore</code>
* [http://wiki.ros.org/Master Master]: implemented by the [http://wiki.ros.org/rosmaster rosmaster] package, usually started via <code>roscore</code>
==Names==
[http://wiki.ros.org/Names Names] aka graph resource names are unique for each topic, parameter, node, and service in the ros graph. It is a shared namespace; a topic cannot share a name with a node. The [http://wiki.ros.org/ROS/EnvironmentVariables#ROS_NAMESPACE ROS_NAMESPACE] environment variable can be used to scope the ros graph namespace.
==Executables==
* rosrun: launch an executable from a package
* [http://wiki.ros.org/roslaunch roslaunch]: starts collections of nodes specified in a [http://wiki.ros.org/roslaunch/XML launch] XML file
** roscore: roslaunch to start core ros functionality

Revision as of 06:41, 20 February 2019

ROS is a software platform for robotics.

Concepts

  • Topic: a named bus on which messages of a single type are published
    • rostopic list will list active topics on a running rosmaster
  • Package: defined by a directory containing a file package.xml (REP-0127)
    • msg/MyMessageType.msg defines messages for the package, published to topics
    • srv/MyServiceType.srv defines services for the package, supporting request/reply semnatics
  • Node: a named process that performs computation
    • A running node has a type and a graph resource name
    • A node is typically launched standalone using rosrun
  • Master: implemented by the rosmaster package, usually started via roscore

Names

Names aka graph resource names are unique for each topic, parameter, node, and service in the ros graph. It is a shared namespace; a topic cannot share a name with a node. The ROS_NAMESPACE environment variable can be used to scope the ros graph namespace.

Executables

  • rosrun: launch an executable from a package
  • roslaunch: starts collections of nodes specified in a launch XML file
    • roscore: roslaunch to start core ros functionality