Let the Games Begin
The FIRST robotics competition leaps onto a new controller platform
PHOTO: Adriana M. Groisman/FIRST
Throughout the history of sports, technology has come in and changed the game. Football players in the Knute Rockne era of the 1920s, with their minimal padding and leather helmets, played a game much different from the game of today. A 1970s redesign of the gymnastics uneven bars changed that sport dramatically: the bars became smaller and easier to grip and were moved farther apart, enabling the release moves and giant swings we see today. Aluminum bats, also introduced in the ’70s, dramatically increased the number of home runs hit in amateur baseball, changing it from a fielders’ game to a hitters’ game.
Now the sport of robotics is getting some game-changing technology of its own. For the 2009 high school FIRST (For Inspiration and Recognition of Science and Technology) competition beginning in January, a 32-bit PowerPCbased embedded controller is replacing the 8-bit microcontroller that’s been used to run the robots for the past eight years. The event organizers expect that the technology will let more than 43 000 participating high school students tackle tougher challenges than those of previous years. The specific task the robots must perform while working against other robots will be announced on 3 January. Previous challenges included throwing balls into goals (Aim High), placing rings onto racks (Rack ’N’ Roll), and stacking pyramids onto goals (Triple Play).
Inventor Dean Kamen founded FIRST in 1989 to inspire young people’s interest and participation in science and technology. FIRST oversees a range of robotics competitions, including the Junior FIRST Lego League, the FIRST Lego League, the FIRST Tech Challenge, and the FIRST Robotics Competition, geared to students of different ages from elementary school through high school. In the FIRST Robotics Competition, the most advanced level, high-school-age students work side by side with professional engineering mentors to build a robot. The students have six weeks to design, construct, and test their robots to meet the season’s engineering game challenge.
The FIRST organization decided in 2007 to give the robot builders a new central controller—the nervous system of the robot. Since the inception of the competition, the control system has been redesigned several times. The early processor, an 8-bit Motorola 68HC811, could not be programmed by the user. In 1997 the FIRST competition adopted a programmable CPU, the Basic Stamp from Parallax; in 2004 it switched to a PIC 18F8520 40- megahertz controller from Microchip Technology and has now moved to using an embedded controller with the 32-bit 400-MHz PowerPC chip. The communications system evolved as well, from direct tether control in 1992, to one-way radio control from 1993 to 1999, to bidirectional radio communication from 2000 to 2008, to Wi-Fi for 2009. Along with the 400-MHz Freescale PowerPC processor, the new controller, tagged the CompactRIO, for reconfigurable input/output, incorporates a field-programmable gate array (FPGA) to work with a variety of input and output devices. The kit of robot parts provided to this year’s competitors will include five plug-in modules that can be used to connect the CompactRIO to a variety of sensors; the modules take signals from the sensors and convert them into data that the controller can process. This year’s five modules include both analog and digital inputs and outputs. In future years, FIRST organizers can change the number or kinds of I/O modules in the kit.
The new flexibility and processing power means that robots should be better able to handle the complex control and signal-processing algorithms required to operate autonomously—that is, without being ”driven” from the sidelines by handlers; in previous competitions, robots were required to spend 15 seconds operating autonomously, but one-third of the teams didn’t attempt to score during this period. The souped-up processing power also means that the robots will be able to handle more complex image data in real time, identifying shapes or doing optical character recognition—they will be robots that can read.
Competitors will be able to program the CompactRIO controller using standard C++ language or a custom version of National Instruments Corp.’s LabView graphical programming software, adapted specifically for the competition. The FIRST organization will in either case start the students out with built-in libraries of example codes and preprogrammed sequences. These resources will let teams get started developing the robots quickly, easing the learning curve. To exploit the full potential of the robots and win competitions, however, team members will have to come up with code of their own.
Robot applications, such as raising an arm while driving forward, are inherently parallel. The LabView graphical programming language is a parallel data-flow language allowing programmers to call for multiple tasks to be executed at the same time. So FIRST robots might be simultaneously acquiring a signal measurement and starting a motor to move the robot forward. Students will also be able to write programs, using either LabView or C ++, that allow their laptops to receive and display information sent wirelessly, including sending images from the camera, data on the performance of the motor, sensor values, and battery voltage. They can also use the wireless connection for real-time debugging and monitoring. In future competition years, this may also be used for robot-to-robot direct wireless communication during play—imagine robots trash-talking the competition.
Participants will come out of this competition with some real-world skills. CompactRIO and LabView are widely used in industry to solve a variety of problems, from motion control to industrial monitoring to in-vehicle data acquisition. For example, Torc Technologies and Virginia Tech used CompactRIO in the DARPA Urban Challenge to create a drive-by-wire system to perform throttle, brake, and steering control.
Right now, the FIRST teams are forming for the 2009 competition. They’ll be receiving their kits containing the CompactRIO controller in December 2008. The task will be announced on 3 January 2009. And starting in March, we’ll begin to see just how game changing the CompactRIO platform will be. Evolution, from the first matches in March to the finals in Atlanta, from 16 to 18 April, will likely be rapid; competitors will be rebuilding and reprogramming their robots on and off the playing fields all the way through.
About the Authors
Ray Almgren is vice president of product marketing and academic relations for National Instruments and leads the worldwide academic relations program. He pioneered many of the company’s academic and university relations programs, including the Lego Mindstorms Classroom Mentor program.
Mark Walters is an academic product manager with National Instruments. He graduated from the University of Texas at Austin with a bachelor’s of science in electrical engineering.