|By Janice J. Heiss, September 22, 2005|
On October 8, the 20 top cars will compete in the finals, navigating 175 miles of Mojave Desert terrain, encountering both natural and man-made obstacles, to win a grand prize worth $2 million. The winner must complete the route, which will not be revealed until two hours before the event begins, within 10 hours.
The DARPA Challenge, only in its second year, has not yet been won -- no car successfully completed the 2004 competition. The farthest any of the 15 competing cars traveled in the 2004 Challenge was 7.4 miles.
Named after Thomas Jefferson, Tommy is a gas-powered custom-built dune buggy, roughly 12 feet long, 6 feet wide, and 6 feet tall. Its egg-shaped aluminum exterior is fitted for drive by wire servo and actuator controls. The design is intended to strike a balance between navigability and stability.
Tommy's sensory technology mixes off-the-shelf and customized laser radar, radar, GPS, and other technologies that enable it to "see" and "determine" what lies ahead. The computing hardware platform is an economical array of modern off-the-shelf components.
Both Tommy's "brains," used for planning and decision making, and its "muscles," used for actuation, reside comprehensively on Java platforms. Tommy's software is built on a Java technology-based platform developed by Perrone Robotics, Inc. (PRI), called the Mobile Autonomous X-bot (MAX). PRI-MAX is a general-purpose robotics platform applied separately to Tommy's main planning and microprocessing, which involves actuation with feedback.
PRI-MAX runs on the Java Platform, Standard Edition (Java SE, formerly known as J2SE), and uses the Java Communications API. A general-purpose Unmanned Ground Vehicle (UGV) framework, PRI's MAX-UGV, also written in the Java language, resides on the PRI-MAX platform in support of the Grand Challenge application. These brains process synchronous and asynchronous sensor information and events from other Java technology-based processors and microcontrollers. Using this data to formulate navigation plans, determine position and orientation, and resolve obstacles, Tommy can establish appropriate speed, steering, and braking actions.
Tommy's microprocessors rely on a hardware-based Java Virtual Machine (JVM) running Java Platform, Micro Edition (Java ME, formerly known as J2ME). The microcontrol platform is a version of PRI-MAX (PRI-MAX, micro profile). Commands are sent to controllers over serial ports, and controllers receive feedback data from motor encoders. Controllers must act in real time, at high rates, and with the low latency that a feedback-driven dynamic mechanical system inherently requires.
Tommy has overcome enormous challenges to compete in the DARPA Grand Challenge, not least of which includes demonstrating that a Java application could achieve something thus far not accomplished. The use of Java technology in a novel application that drives a tightly coupled mechanical-industrial system, along with the PRI-MAX, which sets down a flexible platform that can be used to drive any mobile robot, reflects favorably on the platform's adaptability, flexibility, and extensibility.
Stay tuned for more news about Tommy as events unfold!