Overview
Purpose: ME-588 class project
Creator: Team 3
My Role: Team Leader, Mechanical Design (including all CAD modeling), Library programming
Form
Drivetrain: Two-wheel differential drive.
Controls: Two Arduino Unos, connected using I2C
Sensors:
- Front-facing long-range Sharp IR Rangefinder
- Internal short-range Sharp IR Rangefinder (for ball collection and firing)
- Pololu wheel encoders
- 5 line sensors
- Switch to select offense/defense mode
Fabrication: A large majority of Apollo's components were designed to be waterjet cut out of a single sheet of aluminum in a single operation. This allowed many components to be created quickly, accurately, and at relatively low cost.
Function
Offense: Autonomously picks up tennis balls and launches them over defenders into the goal.
Defense: Blocks shots from entering the goal.
Movement: The drivetrain allows the robot to move with precision and turn on a dime. One line sensor is placed specifically to allow the robot to turn about that sensor and easily align itself to the line.
Positioning: Apollo uses its line sensors and IR sensors to locate itself on the field.
Ball Intake: The wide intake roller allows significant position uncertainty. An archimedes screw centers the ball. The spring-loaded roller tightly grips the ball, and pushes it up into the catapult.
Catapult: The spring-loaded catapult is very consistent, and was designed with a slotted connection to allow the firing power and angle to be tuned significantly during testing. From the chosen firing position, Apollo consistently fires into the goal, but over opposing robots.
Catapult Release: The catapult release is a novel rotational design which uses only a single moving part, but holds the catapult without power, and can be released with relatively low power.