Contents
Getting Started with Turtlesim
Start the roscore:
$ roscore
To install and start the turtlesim:
$ sudo apt-get install ros-$(rosversion -d)-turtlesim
Run turtlesim:
$ rosrun turtlesim turtlesim_node
You'll see the turtlesim window:
Nodes
New in ROS hydro As of Hydro turtlesim uses the geometry_msgs/Twist message instead of its own custom one (turtlesim/Velocity in Groovy and older). Also the topic has been changed to cmd_vel (instead of command_velocity before).
turtlesim_node
turtlesim_node provides a simple simulator for teaching ROS concepts.Subscribed Topics
turtleX/cmd_vel (geometry_msgs/Twist)- The linear and angular command velocity for turtleX. The turtle will execute a velocity command for 1 second then time out. Twist.linear.x is the forward velocity, Twist.linear.y is the strafe velocity, and Twist.angular.z is the angular velocity.
Published Topics
turtleX/pose (turtlesim/Pose)- The x, y, theta, linear velocity, and angular velocity of turtleX.
Services
clear (std_srvs/Empty)- Clears the turtlesim background and sets the color to the value of the background parameters.
- Resets the turtlesim to the start configuration and sets the background color to the value of the background.
- Kills a turtle by name.
- Spawns a turtle at (x, y, theta) and returns the name of the turtle. Also will take name for argument but will fail if a duplicate name.
- Sets the pen's color (r g b), width (width), and turns the pen on and off (off).
- Teleports the turtleX to (x, y, theta).
- Teleports the turtleX a linear and angular distance from the turtles current position.
Parameters
~background_b (int, default: 255)- Sets the blue channel of the background color.
- Sets the green channel of the background color.
- Sets the red channel of the background color.
mimic
mimic provides a simple interface for making one turtlesim mimic another.Subscribed Topics
input (turtlesim/Pose)- The input topic for the mimic node. The topic must be remapped to the pose topic of the desired turtle to mimic.
Published Topics
output (geometry_msgs/Twist)- The output topic for the mimic node. The topic must be remapped to the cmd_vel topic of the mimicking turtle.
Turtlesim Video Tutorials
Python Tutorials
Linear Motion
Go to goal behavior