Robotic Ball Collector
Robotic Ball Collector - Team Chompions
iRobot Co-Op, Fall 2023, Hungry Hungry Roombas Competition
For the project, I was the Lead Mechanical Engineer of the team. I was responsible for the CREO CAD and modeling of our prototype. The CAD used Top-Down Skeleton modeling to manage all the components of the robot.
The Task and Design Specifications
Collect as many ball pit balls as possible and deliver them to your respective scoring zone. Do so, while competing with another team's robot. Be able to manually drive around. DO NOT turn balls into a projectile (we may have stretched this rule).
The Solution
Bluetooth-controlled Robot on iRobot Create 3's platform
Effective spinner to collect balls
The robot stores balls until they need to release
Style points
Chompions Commercial v2 (1).mp4Commercial for THE CHOMPER
Research and Inspiration
The main inspiration was this tennis ball collector
Using a 'sweeping' method to guide the ball into a collection bin
This bin will store the balls until it is time to deliver them
With this research, I took the lead to incorporate the mechanical components onto an iRobot Create 3
Mechanical Design
CREO CAD and Skeleton
I designed a full ASM in CREO using top-down skeleton modeling skills
The main skeleton of the CAD manages all part dimension definitions, part interactions, assembly tolerances, electronic components interaction to mechanical features, and placeholders for interchangeable parts
As seen, the skeleton uses mainly datum planes, as well as surfaces and curves, which I learned to be very useful when doing this type of modeling
The skel is designed to take into consideration assembly and hardware considerations as well, especially for quick prototyping purposes
Key Features
A front spinner that has fins to collect balls
A ramp in which the balls travel up as they are being collected
A 'collection bin' that guides the balls down and towards the back with a 3-degree decline from where the top of the ramp is
Mesh (yellow) that ensure balls are collected
A 'backdoor' that swings open once the bin is full. All the balls exit due to gravity from the decline of the ramp
Electrical, Systems, and Control Overview
Create 3 for movement controls, the iRobot Create 3 is an almost fully open source robot (see link) that we hacked to work with Bluetooth ps4 controller
Directly hooked up Arduino to Create 3's power source and regulated voltage respectively
HC-06 Bluetooth Module for Arduino connectivity to controller
SG90 Servo as backdoor controller
2x TT motors and L298 motor driver to control the spinner
PWM in code for variable spinner control
Check out the GitHub Repo published by one of my partners:
Final Design
After much prototyping for the spinner material, ramp incline, mesh material, we came to this final prototype
The mesh fully encloses the collection bin so it is nearly impossible for the balls to be flung out and seen as a 'projectile'
You can also notice the mecanum wheels under the TT motors on the supporting disks. These were my solution to the ramp rubbing on the ground while the robot was moving. Due to the front heaviness of the robot, the ramp will rub no matter what. The wheels elevate the ramp and allow for more efficient rotational movement
Also some creative design in making it 'look' like a hippo to appeal to style points
The Competition
Our extensive testing and efficient design prepared us for any challenges competition day would hold
We had no technical difficulties, unlike our competitors
The spinner worked perfectly
In the video, notice the backdoor releasing the balls into our score area. The most we've held at one time was 95 balls.
Won 1st place prize for collecting the most balls against our competitors
Robotic Ball Collector - Google Chrome 2024-01-26 12-37-10.mp4Takeaways
"Perfect is the enemy of good"
At one point we had everything fully finished and working perfectly with our design but decided to try out a new spinner material. This new material was too stiff and stalled out and stripped the gears of the motors. So those needed to be replaced. The quote above means that striving for perfection can lead to never improving or falling back to square one; which was an important lesson our team learned during this project.
Shoutout to my teammates:
Daniel - Project manager, software, and systems integration
David - Electrical engineer and software integration
