Project
| # | Title | Team Members | TA | Documents | Sponsor |
|---|---|---|---|---|---|
| 15 | Bike with Fully Electric Architecture |
Ellie Urish Jason Zou Willard Sullivan |
Matthew Qi | design_document2.pdf design_document1.pdf final_paper1.pdf photo1.jpg photo2.jpg presentation1.pdf proposal2.pdf proposal1.pdf video1.mp4 video |
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| # Bike with Fully Electric Architecture Team Members: - Jason Zou (jasonz3) - Ellie Urish (adamwu2) - Willard Sullivan (wrs3) # Problem Most current electric bikes use a combination of chain and motor to provide pedal assistance. The issue with these systems is the complexity of dealing with chain and motor simultaneously. The complexity of these systems that are constantly exposed to the elements means that durability is a concern. This problem is especially prevalent with bike sharing programs, where easy maintenance and care is essential to keeping costs down. # Solution Our idea is to construct an electric bike/moped that is fully powered by electricity. What this means is that instead of using a chain to transfer human power to the wheels, the pedals would instead be connected to an electric generator which would then feed a motor for the wheels. While this configuration is not as efficient for driving the wheels as a direct chain would in terms of just human power, what this configuration allows for is a very simple mechanical design with few moving parts. This could allow for very little maintenance, as there is no longer a chain or gears to take care of and most of the components can be sealed away from the elements. Going to an all electric system would also allow for regenerative braking to be implemented more elegantly, allowing for energy to be recovered during braking and a better experience on hilly terrain while also reducing wear on the brakes. # Solution Components ## Subsystem 1 - Generator The purpose of the generator is to generate electricity from the mechanical rotation of the pedals. We aim to use a 24-48V generator, which is connected to a gearbox that is then connected to the bike’s crank/pedals. One of our main goals is to make this system as durable as possible, so the generator subsystem will be completely enclosed. Example Generators: - 300 Watt Bicycle Generator 3/8" Belt Drive Pedal Power Pulley Dynamo 12V-48V AC DC Wind Turbine Generator PMA 350W 500W 1200W 1800W 2000W 2500W 3200W ## Subsystem 2 - Drivetrain The drivetrain subsystem will be connected to the controls/electronics system to power the rear wheel. The drivetrain will consist mostly of a motor that is connected to the rear hub with controllability via potentiometer from the handlebars. We plan to use a 48V DC motor, ideally controlled with an off the shelf motor controller. Example Motor Controllers: - https://www.americancontrolelectronics.com/dcr600-60 - https://www.americancontrolelectronics.com/dcr600-6 Example Motors: - https://www.amazon.com/Ebike-Front-Electric-Bicycle-Conversion/dp/B0BCK5JTVD/ref=asc_df_B0BCK5JTVD/?tag=hyprod-20&linkCode=df0&hvadid=598359160004&hvpos=&hvnetw=g&hvrand=9148421633832203042&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9022196&hvtargid=pla-1875774232469&th=1&psc=1 (integrated into wheel) ## Subsystem 3 - Controls/Electronics The controls/electronics system will have the ability to route the generative power to the drivetrain or to the battery (if included in this project). With the assistance of a PID controller, our subsystem can be more efficient and limit the power consumption of the drivetrain subsystem. Furthermore, as an additional goal for our project, we aim to have this subsystem control the “launch control” of the bike so that the user does not have to struggle with starting at rest. The electronic system will be based on a custom PCB with a microcontroller and output pins to connect to other components. It will control charging/discharging of the battery, speed of the drive motor, and reading the potentiometer to determine desired speed. # Criterion For Success Describe high-level goals that your project needs to achieve to be effective. These goals need to be clearly testable and not subjective. ## Main Goals - Obtain at least 40% efficiency with the power transfer from the generator to the drivetrain. This is tested by turning the pedals a known distance at a known speed, and then measuring the distance traveled by the rear wheel. - The rear wheel can move at a top speed of 10MPH, tested by holding the bike on a stand and measuring the RPM with a tachometer. - Fully battery powered operation - bike can begin moving from a full stop using battery power without pedaling necessary ## Reach/Extra Goals - Regenerative braking - charging battery from free spinning of rear wheel - Integrating different drive modes - Integrating a super capacitor buffer system |
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