The 2008 Game - Overdrive

This year’s game was named Overdrive, after the racetrack inspired design of the playing field. Designed to best utilize the new technology and concepts being introduced into the FIRST Competition, Overdrive is another in a long line of FIRST Challenges that has continually challenged the skills and innovation of Team 694.

The Field

The playing track of the Overdrive game is a field with one lengthwise lane divider 6 feet tall partially dividing the field into the Red and Blue Lanes. This lane divider, which is bounded at both ends by lane markers, forms a track around which the robots proceed counterclockwise over their respective finish lines to score points. The lanes are divided themselves into sections known as Home Stretches, which are the quadrants of the track that are before the finish lines of each alliance.

Above the finish lines of the track, which are located in the middle of each lane of the track the fence divides, there is an overpass that stretches the width of the field. This overpass, which is 6 ½ feet in the air, is constructed of steel pipe and has on its rails a series of spacer bars, which form three target locations over each lane where the trackballs can be placed.

The trackballs, which are 40 inches in diameter and weigh 10 pound each, are fabric-covered balls filled with air. There are four trackballs in each game, two blue ones and two red ones, with one each of the red and blue trackballs having white dots for identification purposes.

At the ends of the playing field, there are two Alliance Stations, where the robots are controlled during Teleoperated mode. Next to these stations are two other stations, known as the RoboCoach Stations, where the RoboCoaches of each team use remotes to direct their robots during Hybrid Mode.

The Match

The Match is a competition between the Red and Blue Alliances, which are composed of three robots each, who in order to win must score more points than the other alliance does. The robots of the alliances start with their robots in their home stretches, touching their Alliance Station Wall or the angled portion of the wall next to it. The trackballs are randomly placed on one of the target positions on the overpass.

During the match, several rules must be followed by the robots of each Alliance lest they be punished by the referees supervising the match. Some of these rules include the requirement that robots only be in possession of one trackball at a time, and others include punishments for deliberately interfering with the function of another robot. One particular rule involves letting a robot pass another, slower robot by nudging it as a signal of its desire to pass.

The match consists of two periods, the Hybrid and Teleoperated periods. The match begins with the 15 second Hybrid Period, which was inspired by the way NASA scientists controlled the Spirit and Opportunity rovers on Mars. Since Mars is too far away for a scientist to make every decision for the robot, the scientist relies instead on the robot’s basic, built in intelligence to accomplish goals set by the scientist, who makes the big decisions. This was replicated in the Overdrive game, where the robots are forced not only to rely on their own programming, but also on remote input through a remote control and an IR sensor on the robot from RoboCoaches on the sidelines of the match. During the Hybrid period, 4 points are awarded for a robot that crosses either finish line or lane marker, and 8 points are awarded for each trackball removed from the overpass.

After Hybrid period, the Teleoperated period begins. The Teleoperated Period is when the drivers on each alliance step up to their controls and control the robot’s actions directly. During the Teleoperated Period, every robot and trackball that crosses its finish line is awarded 2 points, and if the trackball is hurdled over the overpass, an extra 6 points is added. If, at the end of the match, a trackball of an alliance is back on top of the overpass, 12 points are awarded to that alliance.

In both the Hybrid and Teleoperated periods, trackballs can be manipulated by either possessing the ball, in which the ball’s weight is supported by the robot, or herded, when the ball is simply pushed around the track. A robot may not possess the ball of the opposite alliance, and it may not herd another ball once it is in possession of a ball.