Imagine, if you will, a tricycle. If that's not possible look to the left. This year's 'Iobotics FIRST Robotics Competition robot will feature a new type of drive train system, with interesting physics built in. It is the Reverse Tricycle - All Wheel Drive system or RT-AWD for short. This system is slightly more risky than that of a normal four wheel skid-steer all wheel drive, but is simpler than a four wheel swerve drive system. It is riskier because its center of mass must remain within the triangle formed by the three wheels at all times, or it will tip over and fail miserably. This means that everything heavy should be kept near the front, or is counter balanced on the other side. It is less complicated than a full swerve drive system because only 1 of the 3 wheels rotate, as opposed to all four or even two of the four. Accompanying the extremely fun center of mass equations is the inclusion of the drive programming equations. The equations use the fact that the back wheel that rotates forms the center of rotation. The two front wheels move in a ratio to the distence to the distance from the center of rotation. Unfortunately the drive system doesn't use any thing like ABS or traction guages that tell when wheels slip using the fact that efficent drive comes from static friction as opposed to dynamic friction. The physics and math required for these drive systems are a little out of our league because they require calculus and differential equations... But thats something to look forward to I guess.
This is just part one of three (maybe three) discribing the three main features of this year's 2009 'Iobotics FRC bot. Thanks for reading...
Mark.
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