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The TurtleBot Follower Demo

Follower Demo

The follower demo will cause the TurtleBot to look for objects in a window in front of it. And it will seek to keep the centroid of the observed objects directly in front of it and a fixed distance away. If the centroid of the object is too far away it will drive forward, too close backward, and if offset to the side it will turn toward the centroid.

Start Demo

Start by ssh-ing (ssh help) (ssh help) into the TurtleBot and start the follower demo:

• To ssh in to a TurtleBot from a workstation computer:

  • determine the IP_OF_TURTLEBOT by using ifconfig (Need more help) (Need more help)

    To determine a computer's IP address and network interface in linux:

    • ifconfig

    You will see something like:

    • lo        Link encap:Local Loopback  
                inet addr:127.0.0.1  Mask:255.0.0.0
                inet6 addr: ::1/128 Scope:Host
                UP LOOPBACK RUNNING  MTU:16436  Metric:1
                RX packets:6658055 errors:0 dropped:0 overruns:0 frame:0
                TX packets:6658055 errors:0 dropped:0 overruns:0 carrier:0
                collisions:0 txqueuelen:0 
                RX bytes:587372914 (587.3 MB)  TX bytes:587372914 (587.3 MB)
      
      wlan1     Link encap:Ethernet  HWaddr 48:5d:60:75:58:90  
                inet addr:10.0.129.17  Bcast:10.0.129.255  Mask:255.255.254.0
                inet6 addr: fe80::4a5d:60ff:fe75:5890/64 Scope:Link
                UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
                RX packets:101983 errors:0 dropped:0 overruns:0 frame:0
                TX packets:37244 errors:0 dropped:0 overruns:0 carrier:0
                collisions:0 txqueuelen:1000 
                RX bytes:49326141 (49.3 MB)  TX bytes:7588044 (7.5 MB)

    • the network interface for the wireless card is wlan1

    • the IP address of the computer is 10.0.129.17

    
    

  • use ssh to connect to the TurtleBot

    ssh turtlebot@IP_OF_TURTLEBOT

  
  

  roslaunch turtlebot_follower follower.launch

Changing Follower Parameters

1. Run the dynamic reconfigure gui on your workstation computer.

   • # pre-groovy
     rosrun dynamic_reconfigure reconfigure_gui
     # groovy or later
     rosrun rqt_reconfigure rqt_reconfigure

2. Select camera/follower on the reconfigure gui

3. Play with the parameters using the sliders; you will see the TurtleBot's following behavior change as you move the sliders.

Android client

As you will learn in the Turtlebot-Android Pairing, you can also launch the follower demo and start/stop following behavior from your Android device. Exciting? then move on!

What Next?

• Panorama demo, that shows you how to take panoramic pictures with your TurtleBot or return to TurtleBot main page.