Group SD0622
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Contents |
THREE WHEELED ELECTRIC BIKE
Group Members: Amar Nishant Singh, Phillip Rickert,Niti Agarwal
Advisor: Prof. Yuvarajan
Supervising Prof: Prof. Joel Aslakson
Client: Ellie Anderson
Client Coordinator: Prof. Schroeder
INTRODUCTION
Our project required us to make a “three – wheeled electric bike”. The purpose of this project is to take a leg powered bike and add the ability to run the bike through an electric motor.
We are making a three-wheeled electric bike for Ellie Anderson, our client.She is suffering from a disease and so,cannot use her legs.This bike will be of good use to her.
S. Yuvarajan This Project is Being Supervised and Guided by Proff. Yauvarajan.
SUMMARY OF IMPACT
Our client cannot use her legs to move around. She remains at home for most of the time in her wheelchair. If she wishes to go
out, then for that she is dependent on her family and friends. A person without disability is able to go out whenever he or she wishes
to. They can go out for small walks or for other stuff like shopping etc. whenever they wish to. But, these delights were away from our client till now. With this bike, she will also be able to go out on her own (to have fun, to enjoy weather, for shopping etc.).Even if, no one is at home to take her out for shopping and other fun stuff, she will be able to go out independently.
The bike has been made keeping in consideration the disability. Our bike can run in two modes: hand powered and electrical. Both modes work independently. So the user can choose either mode as she desires. Instead of a foot powered crank, we have introduced a hand-powered crank. Also, in electrical mode, motor receives its energy from the battery and so the bike moves with no effort at all from the rider’s side. For her safety, there is a mechanism for over-current protection. We have also provided her, a display which will give her the status of distance traveled, speed of the bike and the battery level. There are headlights and tail-lights which will let her use the bike in low light situations. For her convenience, there is a basket attached at the back where she can keep her stuff.
REQUIREMENTS
The main parts of our project are:
Tricycle
Motor
Batteries
Hand Crank
Throttle
PIC Interface
Head/Tail Lights
Recharging Unit
Obviously the central idea of this project is the tricycle. We have selected a suitable tricycle that will meet the demands of our client as well as having a suitable frame so as to match our design needs for it. It should be both comfortable and practical in size and weight.
Another extremely important aspect of this project is the selection of the motor. We have selected a motor that will provide enough power to move the tricycle at a decent pace, yet it still remains small and lightweight. It is a 24V 300W motor to provide the proper amount of torque.
The third and final critical element of the project is the batteries. For this project we will be using two 12V batteries in series to achieve the necessary 24V to power the motor. The batteries can power the bike under normal usage for approximately 1 hour.
The hand crank is an item that we modified onto the tricycle. Because of the needs of our client standard foot power is not an option. So in the situations where she might either run out of battery power or just choose to control the tricycle herself she has the hand crank option. This was modified onto the handlebars and positioned in a suitable location. Any mechanical power from the hand crank will be directed to the front wheel through the use of a standard bike chain.
PROJECT DESCRIPTION
We started working on other aspects like PIC, motor, thumb-throttle etc. first. Then, we bought a leg powered bike and got it converted into a hand-powered one. Mr. Guy Nelson and Mr. Red, on the recommendation of Prof. Joel helped us out with it.The link shows the modifications Bike.pdf Then, we worked on the technical aspect of our bike. The main areas of focus for our project are centered around the motor, the batteries, and the user interface. Let’s discuss each part in detail.
Motor: We have used 24 V 300W brush-less DC motor. It can easily drive up to a 250 lb or greater load.
Batteries:We are using two 12 volts 18 Amp hr batteries for the bike. The batteries can power all the electronic gadgets installed in the bike along with the motor. The batteries can drive this bike continuously to 1hr with all features at max. The batteries can be charged using any two 12V or one 24V @ 5amp charger.
PIC: PIC takes up pulses from optical sensor. It is programmed to calculate speed, distance traveled and battery level.
Display: It displays Speed, distance covered and battery level. Our display has 4 rows and can display 20 characters in each row (4x20).
Thumb Throttle: It is actually a 5kΩ variable resistance which is attached to the controller of the motor for changing the speed from 0 to Max. The throttle also has auto reset function so the motor stops if the throttle is released, preventing accidents.
Over-Current Protection: The mechanism involved behind over current protection is as follows. There is a circuit Breaker in the bike which stops the flow of over current. It trips whenever there is a flow of 30 Amps of current in the circuit.
The hand power feature of our bike works independently. It has nothing to do with the motor. The rider can switch to hand power mode when batteries are dead.
The Bike we modified
