Hardware: The Robots
The robots we are focusing on in this project include the Pioneer family (Pioneer, Pioneer2, PeopleBot robots) and the Khepera family (Khepera and Khepera 2 robots).
The Pioneer 2-DXE, shown above, weighs 50-60 lbs. The basic robot comes equipped with two motors, one controlling each wheel. The robots have two groups of 8 sonar sensors, with one group at the front and another at the back. A pan-tilt-zoom camera and a gripper are shown in the configuration above. The front of the gripper acts as a bump sensor. A back bumper is also available. For more information on Pioneers, see http://www.activrobots.com/
The Khepera series of robots (above) are small robots (about 70 mm in diameter), weighing about 80 grams. The basic robot comes equipped with two drive motors and eight IR sensors that can be used for sensing distance to obstacles, and also sensing light intensities. Kheperas come with several add-on hardware modules that include grippers, cameras, etc. See K-Team's web page for more information.
Even though the two platforms are quite diverse, at an abstract level, they have similar functionalities. While the Pioneers are large and need a lot of floor space to move about, the small size of the Kheperas makes them eminently suited for desktop robotics experiments. The picture below shows both the robots together for the sake of size comparison.
Often, it is useful to test robot control programs on a simulator before trying it out on a physical robot. This not only helps in debugging, but also speeds up the cycle time of learning experiements where a large number of iterations are required. Several simulators are available that simulate the two robots: Aria (also called SRISim) and Saphira simulate the Pioneers and there is also a Khepera simulator available.
Also available is a versatile simulation and robot programming environment, called Player and Stage. Stage is a multiple robot simulator and Player is a device driver/server that enables robot control. Player and Stage were developed jointly at the University of Southern California Robotics Research Lab and HRL Labs and are freely available under the GNU General Public License from http://playerstage.sourceforge.net. Currently, Player/Stage provides excellent support for the Pioneer family of robots. Similar facilities for Khepera robots are under development and will be available in the near future. Due to the versatility of Player/Stage we will most likely adopt it as our standard simulator.