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.

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

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

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

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 www.assistedliving.com www.seniorerrandservice.com Project Mechanical Electrical Future Work 5/17

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

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

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

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

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

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

Electrical Design Process Project Mechanical Electrical Future Work 13/17

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

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

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 www.directindustry.com www.linbenton.edu Project Mechanical Electrical Future Work 16/17

Questions?