Overview
The Boston SPDLtics were tasked with designing and building a Kinetic OrB Elevator (KOBE) that can autonomously navigate around an Arcade to deposit shrunken foam Skee-Balls into a basket.
In true Kobe Bryant fashion, our KOBE embodied the three-peat through a three-tier stack. The bottom-most platform was the drivetrain foundation, the middle was the electrical mounting area, and the top was the shooting station. The main components were primarily two drive motors, a fly-wheel launcher with indexer, IR receiver, and three opto-reflective sensors. |
Arcade Arena
The Arcade that our KOBE had to play on is pictured above, being split in half to compete head-to-head with another KOBE. There are infrared transmitters above each team's basket to identify the shooting direction. The robots could only reload three balls at a time while in the reload zone and would score points based off the colored regions. For example, if the robot was completely within the teal region and made a basket, the team would receive 5 points. Our KOBE feared no challenge and decided to tackle the scoring by swishing consistent 3-point shots into its respective basket.
Strategy Overview
Our original strategy was to load a hopper with balls, exit the loading area, then immediately re-enter, loading up another three balls and continuing this until the KOBE’s hopper was mainly full. The KOBE would then drive to the 3-point line through the assistance of the tape sensors and put faith in the Mamba mentality of 32.9% three point shooting. KOBE would shoot as many 3’s as possible within the allotted time using the shooting motor with PI control for consistent results.
After a downsizing of scope, our KOBE instead loaded a feeder with three balls and drove to the 3-point line. It shot all three balls and then reversed back into the reload zone to load another three balls. The robot continued this series until time ran out. A detailed overview of our final strategy can be seen in the block diagram above.
After a downsizing of scope, our KOBE instead loaded a feeder with three balls and drove to the 3-point line. It shot all three balls and then reversed back into the reload zone to load another three balls. The robot continued this series until time ran out. A detailed overview of our final strategy can be seen in the block diagram above.
The video below shows a demonstration of one complete cycle of our gameplay strategy. The KOBE is initiated with a button press, which raises the game flag (not visible in this video). Then, the KOBE rotates clockwise until it aligns with the IR beacon and turns on the LED color corresponding to the beacon frequency (i.e. the team the KOBE is playing for this round; also not visible in this video). The robot then turns on its launch motors and drives forward, turning left to look for the black center line on the field. After crossing the line, the robot realigns with the beacon and proceeds forward until it crosses the 3-point line. It then backs up behind the line and starts the shooting sequence, firing 3 balls. To reload, the robot returns to the loading zone (veering slightly right to ensure it remains in the right half of the arena per our navigation algorithm) until a limit switch on the back of the robot is triggered. The robot is then reloaded and the process repeats when a button is pressed on the top of the robot.
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The above video is from testing to determine the accuracy of our flywheel shooting mechanism from our intended shooting position behind the 3-Point line. 32.9% three point shooting? More like 100%!
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The above is an early video of our KOBE being tele-operated and scoring two shots worth 2 points each, totaling 4 points.
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