Initial Design

Mock-Up

Mechanical Design Concepts

Mobility: Omni-directional wheels on servos

• Easy movement in any direction
• Can use servo information for localization/position of robot

Catching: Large net bowl

• Net chosen to soften landing
• Relatively simple mechanism

Throwing: Simple rotating arm on servo

• Simplest mechanism, distance ball is thrown is controlled by final servo position
• Fling arm bucket will be designed to induce a backspin on the tossed ball

Electrical Design Concepts

Microcontroller: Arduino Nano for robot control (excluding vision)

• Enough I/O and processing to interact with all desired sensors and servos
• Easy to use, low power, cheap, & small

Motion: Full rotation metal gear servos actuating omni-directional wheels

• Precise control with pwm signal from microcontroller
• Fast/strong enough for this lightweight application

Throwing: Metal geared servo with lever arm and basket attached

• Simple pwm control
• Should be strong enough to launch to desired distance

Power Supply: 3-4 Cell Lipo battery -> 5V buck converter regulator

• Already have lipo batteries, connectors, wire and charging supplies from fpv drone experience
• Lipo batteries will be able to deliver enough current to easily run the system
• Short matches mean low capacities around 1400mah will suffice
• 5V buck converter efficiently regulates voltage output and has high current capability

Perception/Sensing: IR sensor to detect if robot has ball

• Easy to use and have experience working with them
• Reliable pwm signal sent out which Arduino ADC can measure

Vision: Raspberry Pi Digital Camera

• This option will allow for easy integration of video feed into image processing software

Vision Processing: Raspberry Pi 3

• OpenCV will run on this platform just fine
• Internet connection, full Linux OS

Software Design Concepts

Low Level Control Code: Arduino (C/C++)

• Since our servos are controlled via Arduino, we will leverage C/C++ to control movement

High Level Control: Python/C++ (ROS)

• Interface between move command/waypoint navigation and low level control

Vision: Ball Detection with Raspberry Pi Camera (Circle Detection with thresholding)

• Computationally simple (need to run on Raspberry Pi)
• IR source on Kinect makes skeletal tracking difficult on open floor of Kelley

Code Repository: Github

• Source Control
• Redundancy

Block Diagram

Functional Flowchart

Group Concept Proposal