Omni-Wheel Robot

For CE-218, Mechatronics, my team and I were required to build a robot for our final project. The goal of this project is to create a robot within certain specifications that can meet a required goal. This year’s project was named Slug-o-Lete; and the tasks involved the robot acting as a bull, and a toreador. In both modes the robot is to stay within a seven foot diameter circle using tape sensors, and to respond to bump sensors. The robot will have a switch that allows the robot to change from bull to toreador mode and back again.

Two robots will be placed in the seven foot diameter circle, a.k.a. the ring, at the same time. The bull mode robot is to locate the other robot, and ram them as many times as possible. After each successful ram, the robot will move backwards to prepare for another ram. In toreador mode, the robot will locate the bull robot, and attempt to shoot ping pong balls into a cup on its back, while avoiding the bull at all costs.

The full specifications and requirements for the robot can be found on the class website: HERE.

From a high level, the robot was implemented using Solidworks, a laser cutter, batteries, DC drive motors, various sensors and circuitry, motor drive boards and a Motorola 9S12C32 microcontroller.

Subsystems:

Structure. The structure was designed in Solidworks, and burnt our of medium density fiberboard (MDF) using a laser cutter. Zip ties and wood glue were used for construction.

structure

Locomotive. 4 DC motors (Jameco 161382s) were used to move the four Kornylak 4″ transwheels. Motor driver circuit boards were provided for the class.

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Power/Batteries/Distribution. Two sets of 7.2V 3800mAh batteries were used. We used regulators to make a 7.2V rail and a 14.4V rail.

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Control. The class provided a Motorola 9S12C32 microcontroller board, that C code was run on.

Beacon Sensing. Was completed using two IR photodarlington sensors, a mux, and sensor circuitry that was developed in lab 2.

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Tape Sensing. This was done with 4 tape sensors to keep the robot within the ring.

Collision Sensing. Completed with a total of eight button switches that had an MDF stick glued to them. All switches had debounce circuitry installed.

Cannon and Ammo. Contructed out of 40mm PVC pipe, custom aluminum ducting, hot glue, a rotary computer fan, a 40mm Prestone automobile preheat tube, a 40mm PVC stopper and a 1A solenoid.

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Mode Switch. A three-pole center-off switch. Switched between bull, off and toreador. All switches had debounce circuitry installed.

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Media/Links:

Pictures from the quarter…

KSBW News Story on Slug-o-Lete

UC Santa Cruz — Robotics 101 Documentary

Sentinel Article on Slug-o-Lete

Webcast of the Public Demo

Conclusion:

The project was a perfect culmination of all the skills we had previously learned in the Mechatronics class. No particular part of the project was difficult, the main focus of effort was getting every sub-system to interact properly.

We look forward to demonstrating our robot at the Bay Area Maker Faire this spring.

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