1. Team 01 Progress Report: RoMow Mk. II
Hello everyone, we are team one presenting our third progress report.
Our senior design project is RoMow Mk.II. Improving upon last year’s senior design project.

2. Team Members Se Ge Jung (ME) Caleb Meindertsma (ME)
Emily Wheeler (ECE)
Aldo Daniel (ECE)
We still have the same team members: Se Ge, Caleb, Emily and Aldo. 
Project
Mechanical
Electrical
Future Work
2/17

3. Presentation Overview
Project Introduction
Mechanical Design Process
Electrical Design Process
Future Work
Today we will reintroduce our senior design project and give you updates on mechanical design process and electrical design process. We will end our presentation with future work. 
Project
Mechanical
Electrical
Future Work
3/17

4. Requirements Team 01 Customer: Professor Kim
Lighter control box with engineering graphic
Adjustable frame (size & height)
Collision sensor
Inexpensive motors
Modular Design
Team 01
Camera mounted
Display video feed
Our customer and mentor is Professor Yoon Kim.
He has given us some requirements:
The design project is to have:
- a lighter control box that is also detachable from the frame. Mk. I had a control box made out of sheet metal and it interfered with the RC antenna. Mk II will use plastic to address this issue.
- Second, the project also needs a lighter frame. Mk. I used steel which made the frame strong and durable but was very heavy. Mk. II will use extruded aluminum and will still be durable enough.
- Third, the frame design has to be adjustable in xyz direction to accommodate more models of lawn mowers and the frame will be foldable for easy storing.
- Next, the collision sensor. Either it be a pressure sensor or proximity sensor. The only safety feature Mk.I had was an emergency stop button. We hope to make Mk.II safer with a collision sensor.
- And lastly, cheap motors that meet specifications. Similar to the previous design team, we are planning to buy an used power wheelchair that will meet our motor specifications.
Additionally, our team wishes to mount a camera on the frame for a safety display video feed.
Project
Mechanical
Electrical
Future Work
4/17

5. Design Norms Caring Integrity Trust Project Mechanical Electrical
Caring: Ro-Mow Mk. II will show genuine love and concern for people. The physical, social, and psychological effects of the customers are one of our highest priorities.
Integrity: With an older generation making up most of the target market it is essential that the design is pleasing and intuitive to use.
Trust: Lastly, the Ro-Mow Mk. II must be dependable and reliable. It is important to establish a bond of trust with the user.
images.wisegeek.com
Project
Mechanical
Electrical
Future Work
5/17

6. Mechanical Design Process
Design modifications
Mechanical team reevaluated the previous design in terms of loading capability and manufacturability and of course requirements laid out by the customer. Control box is made with flexible ABS plastic with 1/16” aluminum brackets so that they don't wobble. The middle section of the lid is attached with piano hinge so that it can be opened and closed to access electronic components easily. The t-slotted aluminum extrusion makes it easy to adjust the size freely. the joints will be fastened with bolt and nut. The height will be adjustable by adding hard rubber spacers for the holders. 
Project
Mechanical
Electrical
Future Work
6/17

8. Mechanical Design Process
Finite Element analysis has been done to determine the loading capability of the platform. The control box is our heaviest component. It will carry over 100 lbs of objects including the two batteries and two giant motors. The analysis on the right show that the quarter inch aluminum plate can withstand the force. It has a maximum displacement about one thousandth of an inch. 
Project
Mechanical
Electrical
Future Work
7/17

9. Mechanical Design Decisions
Motor placement VS
I want to talk over some of the design decisions that we have made. Our motor from the electric wheelchair is tall and while wondering if we should lay it flat or put it upright. We decided to put it upright because it is safer not having the motors bumping and the  control box doesn't need to be as big.
Project
Mechanical
Electrical
Future Work
8/17

10. Mechanical Design Decisions
Joint Fastener
Mcmaster-carr
On this slide you can see the evolution of out joint fastener design. The far left was not strong enough so we redesigned it as shown in the middle. We weren't going to machine those so we ordered some from McMaster-Carr. Top right is a picture of drop in fasteners and bottom right is picture of L-bracket that we will machine. 
Project
Mechanical
Electrical
Future Work
9/17

11. Mechanical Design Decisions
Lawn mower holders VS
This is an ongoing design decision. On the left is lawn mower wheel sitting on top of holder. To lower the lawn mower cutting height even further, we can cut out a section from the holder as seen in the right. The issue is that the tires might touch the ground and different wheel sizes can cause various height adjustments. 
Project
Mechanical
Electrical
Future Work
10/17

12. Mechanical Obstacles How to mount lawn mower to attachment.
Easier way to adjust height and size.
Project
Mechanical
Electrical
Future Work
12/17

13. Electrical Design Process
Project
Mechanical
Electrical
Future Work
13/17

14. Electrical Design Process - Camera
Microcontroller
Raspberry Pi
Steelsquid OS
Raspbian OS
Video feed access
Sends IP address to specified address
Type IP address into any web browser
Project
Mechanical
Electrical
Future Work
14/17

15. Electrical Design Process - Motors
Previous Design
Raspberry Pi
Steelsquid
One motor at a time
Customer suggestions did not fix it
Needed power management for receiver
Current Design
Arduino
Better for handling real-time processing
Safer since it cannot be hacked
Project
Mechanical
Electrical
Future Work
15/17

16. Future Work Electrical Mechanical Get motors working simultaneously
End-user video feed access method
Adding proximity sensors
Battery management circuit design and fabrication
Mechanical
Welding and assembly with fasteners and bolts
Camera mounting – damping system
Testing - cut grass
Project
Mechanical
Electrical
Future Work
16/17

17. Questions?