MECHANICAL DESIGN

The robot's wheels were placed in the center of the footprint allowing the bot to rotate without any translation. In order to make space for our inline launching system, the drive motors were angled perpendicular to the wheels with their torque transferred through 90 deg bevel gears. Each of the motor & wheel 5mm shafts were supported with 3D printed ABS supports that held 5mm ID bearings. Each motor shaft connected to the 5mm drivetrain shaft with a flexible linear coupler in order to mitigate the damage of misalignment. Both the bevel gears and linear shaft coupler were held to the shaft through set screws.

The launching system was placed in-line with the centerline of our robot facing towards the front. This design allows the robot to drive up to ACORNs, collect them with the two servo arms, aim by rotating the robot in a desired direction, then hitting the ACORN straight out of where it came in. The launcher consists of four layers of duron that were tension loaded with two side springs from anchor points at the front of the robot. The launch motor uses a timing belt to rotate a snail cam that pulls back the duron launcher, further loading it against the anchor points. When the snail cam completes it's rotation and suddenly drops to it's lowest points, the potential energy stored up in the launcher gets unleashed, propelling the loaded ACORN in the direction that the robot is currently facing.

Five opto-reflective sensors were placed on the bottom layer of the robot in  order to detect the tape on the field. Two of these sensors were placed just outside of the wheels in order to align the robot at the intersection to prepare for a 90 degree turn. Another tape sensor was placed in the center of the back edge of the robot in order to line the robot up for parallel travel toward the center intersection of between the two trees. Each of the sensors were held at their optimal 5mm away from the ground with a 3D printed mount that extends from the bottom duron layer. The back edge of the robot holds an array of three tape sensors that were originally used for tape following, but use of the two edge sensors was discontinued after a pivot in game strategy.

Two IR detection circuits were created in order to determine the position of the four IR emitting beacons. The circuits were split up to detect the the signal at different ranges: One for the short distance beacons on our side, and the other for the long-range beacons on the opposing side. These detectors were positioned at around 32cm off the ground to stay at height with the beacons and were stationed on a Dynamixel servo in order to be able to swivel without rotating that entire robot. At the start of each round, the servo would scan 360 degrees for the IR frequencies, continuing to scan until the four signals were detected, then stop and send an event to indicate which side of the field the robot was playing on.