Difference between revisions of "Tilting Hokuyo"

Revision as of 19:39, 6 October 2009

Author

Advait Jain (http://www.cc.gatech.edu/~advait)

What this does

Tilting the Hokuyo using a servo and reading back the servo encoder position while getting scans from the Hokuyo allows us to generate a 3D point cloud of the world in front of the robot. We have used this 3D point cloud for object segmentation, door handle detection etc.

• Sample Point Clouds
• Thok pointcloud1.jpg
• Thok pointcloud2.jpg

Pictures of the Setup

• Servo Tilting the UTM
• 

  Firefly Camera, UTM and Servo (left to right)

• 
• 

• Alternate Configuration
• 
• 

Hardware

Image of the solidworks part for the bracket to mount the UTM on to the servo.

This is the hardware setup that we use:

• Tilting servo: Robotis Servo (typically we use RX-28) http://www.crustcrawler.com/motors/RX28/index.php?prod=66
• This gives a serial interface to control the servo: http://www.crustcrawler.com/electronics/USB2Dynamixel/index.php?prod=65
• Hokuyo UTM. (http://www.acroname.com/robotics/parts/R314-HOKUYO-LASER4.html)
• Bracket to mount the Hokuyo on to the servo.
  • This is a custom part that we have designed.
  • The solidworks CAD file will be uploaded soon. This requires Solidworks 2009.
  • We have taken two routes for making the bracket
    1. buy Aluminium channels from http://mcmastercarr.com and drill the appropriate holes.
    2. use http://www.mfg.com to get the part manufactured from the CAD file. Will take between a week to 10 days.

Code

• ROS (http://www.ros.org)
• You will need the following ROS packages from our public ROS repository (available at http://code.google.com/p/gt-ros-pkg/wiki/hrl_content_summary)
  1. robotis
  2. hrl_hokuyo (requires hokuyo_node - http://www.ros.org/wiki/hokuyo_node)
  3. hrl_tilting_hokuyo