FRC 2016 Robot - Pathfinder



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Overview

The 2016 FRC challenge was to build a 120lb robot to cross over a variety of obstacles, defenses, and shoot 10” diameter dodge balls, boulders, into goals in a tower.

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Approach

2016 was my senior year of high school and my teams third year in FRC.

As the team President, Lead Designer, Lead Programmer, and Driver I was looking forward to taking everything I had learned in my first two years in FRC and lead my team.

I was committed to following a rapid prototyping, continuious incremental improvement design approach this season.

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Results

Tech Valley Regional - Finalists (#2 seed), Industrial Design Award Winner


Finger Lakes Regional - Semifinalists (#1 Seed), Quality Award Winner


World Championship - Hopper Sub-Division, Finalists


IRI - Semifinalists



DESIGN


This season we followed an extremely rapid build schedule. In the early weeks we iterated quickly through designs, optimizing farther with each iteration.

Here are some highlights of how we were able to build a fully fuctional prototype by Day 12. And the build an improved and more robust version that would server as our practice robot by day 18.



Day 1

After a detailed analysis of the game we set our sites high.

Our top priorities were to build a robust drivetrain to effectively cross the fields obstacles and to be able to shoot into the high goal.

We had expience with building two speed drivetrains in our first two seasons. But we had never build a shooter.

So right after our game analysis, I started on an initial prototype of a shooter to determine basic wheel spacing and desired compression on the ball.

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Day 2

The Day 1 shooter prototype was effective in helping understand the general behavior of the game piece and the compression required to shoot.

We then moved on to how to feed the ball into the shooter. For this we added a pneumatic piston to push ball into the shooter wheels.

With both compression and feed in place we got to work on determining the angles needed to shot into the high goal from a safe location on the playing field.

With both compression and feed in place we got to work on determining the angles needed to shot into the high goal from a safe location on the playing field.



Day 12

Shooter integrated into a drivetrain and fold down ball collector.

Used to practice in real scenarios driving over defenses, collecting balls, and shooting them into the tower from various locations.

Initial programming done for PID control of arm angle and shooter RPM.

GrabCAD

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Day 18

V2 shooter and drivetrain to address issues with V1.

Shooter pivot improved to incorporate a method of tensioning the chain.

Drivetrain size increases to provide more room for electronics and defense manipulation mechanisms still to be added.

Switched to 8 wheels to decrease distance between wheels to lower chances of bottoming out crossing defenses. The ends of the tubing of the side rails are cut on 60 deg angle to help aid robot at getting over bumps in the defenses.

CAD


As the lead CAD designer I used Autodesk Inventor throughout the entire design process.

Concepts started as 2D sketches to figure out essential geometry, which was then taken to 3D in order to build prototypes. Changes would then be taken from the prototypes to take into the final design and be integrated with the other subsystems.

This is the final result after many iterations to every subsystem on the robot.

GrabCAD

PROGRAMMING


As the teams programmer I used LabVIEW to program autonomous and teleoperated functions of the robot. In autonomous heading and velocity were controlled with encoders and a gyro mounted on the drivetrain. The shooting system was controlled with PID loops monitoring a potentiometer on the shooters angle and encoders mounted to the shooter wheels to maintain a constant wheel speed.

Because of the nature of the defenses vision tracking was used to align with the goal in autonomous. Using a green LED around the camera and reflective tape on the goal the robot was able to self align and shoot at the goal.

GitHub


TECHNICAL DOCUMENTATION


Check out our Engineering Notebook for more documentation.