[Eric] sent in his tutorial on building a Kinect based robot for $500, a low-cost solution to a wife that thinks her husband spends too much on robots.
For the base of his build, [Eric] used an iRobot Create, a derivative of the Roomba that is built exclusive for some hardware hackery. For command and control of the robot, an EEE netbook takes data from the Kinect and sends it to the iRobot over a serial connection.
The build itself is remarkably simple: two pieces of angle aluminum were attached to the iRobot, and a plastic milk crate was installed with zip ties. The Kinect sits on top of the plastic crate and the netbook comfortably fits inside.
A few weeks ago, [Eric] posted a summary of the history and open-source software for the Kinect that covers the development of the Libfreenect driver. [Eric] used this same driver for his robot. Currently, the robot is configured for two modes. The first mode has the robot travel to the furthest point from itself. The second mode instructs the robot to follow the closest thing to itself – walk in front of the robot and it becomes an ankle biter.
There is a limitation of the Kinect that [Eric] is trying to work around. Objects closer than 19 inches to the Kinect appear to be very far away. This caused a lot of wall bumping, but he plans on adding a few ultrasonic sensors to fill the gap in the sensor data. Not bad for a very inexpensive autonomous robot.