PRESENTATION #3Electric Bike Charging and Docking Station: ECE Group 7

Presentation Introduction

● Project Introduction

● Locking System Overview & Testing Results

● Charging System Overview & Testing Results

● Control System Overview & Testing Results

● Prototype Demonstration

● Budget Review

● Conclusions

● Questions

Project IntroductionJustin Hatcher

Project Sponsor

● Bicycle Capital

● Background Information

○ Developing an electric bike sharing

program for the local area and beyond

○ Focused on providing a reliable,

efficient method of transportation

○ Currently have eBike sharing programs

in South America

Justin Hatcher

Problem Statement

● To create a docking station capable of automatically charging and locking the

eBike being utilized by Bicycle Capital

● Major Challenges:

○ How to charge the eBike?

○ How to secure the eBike?

○ How to minimize user interaction with the station?

Justin Hatcher

Needs Analysis

● The eBike charging and docking station should:

○ Be able to efficiently charge an eBike

○ Be able to securely lock an eBike

○ Utilize a front facing docking method

○ Require minimal user interaction

○ Be able to operate in adverse weather conditions

○ Be modular by design and aesthetically pleasing

○ Be cost-effective

Justin Hatcher

Areas of Focus

● Locking System

○ The locking system encompasses how the eBike will be kept secure

○ Includes the station and bracket design

● Charging System

○ The charging system encompasses how the eBike will be charged

○ Includes all electrical components required to charge the eBike

● Control System

○ The control system encompasses how a user will check out an eBike

○ Includes the RFID module that will control the locking system

Justin Hatcher

Locking System Overview Elijah Goodson

Final Station Design

● Height: 37 9/16 inches

● Width: 12 1/8 inches

● Depth: 21 inches

● Weight: 50 pounds

Eli Goodson

Final Station Design

Eli Goodson

Final Station Design

Eli Goodson

Parts List from Top to Bottom:

● Insulation Cover

● Female Charger Connection

● Charging Support

● Latch Support

● Base Plate

● Latch Solenoid

● Wheel Well

Final Station Design Overview

● Initial designs were focused around a linear actuator based design

● Final design uses a latch type solenoid as the locking mechanism

● Why the latch solenoid was chosen:

○ has a fail-safe locked position if no power is supplied

○ less expensive than linear actuators

○ quicker reaction time than linear actuators

○ smaller in size than linear actuators

● The final station design is more simple and more efficient with only eight parts

Eli Goodson

Final Bracket

● Height: 3 inches

● Width: 2 21/32 inches

● Depth: 6 1/8 inches

● Weight: 3.22 pounds

Eli Goodson

Parts listed from top to bottom:

● Insulation Cover

● Male Charger Connection

● Charger Support

● eBike Bracket Attachment

Final Bracket

Eli Goodson

Final Bracket Alterations

● Removed a stability peg to create room

for the electrical components

● Added additional space to run electrical

wires to the lithium-ion battery

● Increased the overhead clearance for the

electrical components

Eli Goodson

Final Bracket Overview

● Bracket has been fabricated from a donated piece of billet aluminum

● Design keeps electrical components hidden from elements

● Design has a more streamlined shape that is aesthetically pleasing

● Electrical components are housed in 3-D printed plastic to keep them insulated

and protected from tampering and weather

Eli Goodson

Final Station Design with eBike Attachment

Eli Goodson

Locking System Testing ResultsHunter Harrison

Station Base Testing

Simulation Testing

● Simulation testing was performed on the station base using Solidworks 2014

● Strength tests and deformation tests were simulated

● Base material used in the simulation testing: AISI 321 Annealed Stainless Steel

Hunter Harrison

Types of Testing Overview

● Strength testing:

○ Applying a load to the component while grounding a specified surface and

seeing how much stress occurs and where the stress occurs

● Deformation testing:

○ Applying a load to the component and seeing how the component will

deform and where the component will deform

Hunter Harrison

Station Base Strength Test Results

● The testing force applied: 2000N (450 lbf)

● The force was applied to the top of the station

● The station was grounded at the base

● Blue coloring indicates low values of stress

● Red coloring indicates higher values of stress

● The station base is sufficiently strong

Hunter Harrison

Station Base Deformation Test Results

● The testing force applied: 2000N (450 lbf)

● The force was applied to the top of the station

● The station was grounded at the base

● Blue coloring indicates low values of stress

● Red coloring indicates higher values of stress

● The station base is sufficiently strong

Hunter Harrison

Bracket Strength Test

● The testing force applied: 2000N (450 lbf)

● The force was applied to the top of the bracket

● The station was grounded at the base

● Blue coloring indicates low values of stress

● Red coloring indicates high values of stress

● Stress is higher around bolt holes as expected

● The bracket is sufficiently strong

Hunter Harrison

Future Testing

● Full scale prototype made of AISI 321 Annealed Stainless Steel tubing should be

subjected to tests such as the ones simulated to validate simulation results

● These tests have not been performed due to the fact that our prototype

station base was created using wood to reduce cost

● The strength of the latching solenoid should also be tested to ensure it can

withstand the proper amounts of stress expected

Hunter Harrison

Charging System OverviewGabriel Sejas

Final Charging System Connection Device

● Final Connection Device:

EZGO Charger Plug

● The EZGO charger is commonly used to

charge golf carts

● This connector was selected because it

can handle the voltage and current

output needed

● The device has internal components that

are easy to connect and disconnect

Gabriel Sejas

Female Charging Connection

Parts List from Top to Bottom:

● Insulation Cover

● Female Charger Connection

● Charging Support

● Latch Support

● Base Plate

● Latch Solenoid

● Wheel Well

Gabriel Sejas

Key Charging System Components:

● Insulation Cover (red piece)

● Male Charger Connection

● Charger Support (yellow peice)

Male Charging Connection

Gabriel Sejas

Charging System Testing ResultsXiaoRui Liu

Charging System Testing

● Testing Goal: To ensure the lithium-ion battery charges at the same rate with

the created Charging System as it does with the standard charger

● Specific Tests:

● Voltage Output Test

● Charge Time Test

XiaoRui Liu

Voltage Output Test

● Test Purpose: To ensure the output voltage coming from the created Charging

System is the same output voltage from the standard charger

● Test Results: Under the same testing conditions the output voltage of the

Charging System was equal to the output voltage of the standard lithium-ion

battery charger

Tested System Charging System Standard Charger

Expected Voltage 42.5 V 42.5 V

Measured Voltage 42.5 V 42.5 V

XiaoRui Liu

Charge Time Test

● Test Purpose: To ensure the total charging time when using the Charging

System is the same as the total charging time when using the standard lithium-

ion battery charger

● Test Procedure: Under the same testing conditions, test the time it takes to

fully charge the lithium-ion battery with the Charging System and with the

standard lithium-ion battery charger; compare the results

● A full charge time test has not yet been completed

XiaoRui Liu

Charging System Testing Conclusions

● The voltage output test was successful as previously shown

● When the eBike was connected to the station, the standard lithium-ion battery

charger recognized the eBike’s lithium-ion battery

● This confirmed that a solid safe connection was made between the charger and

the lithium-ion battery

● The limit to charge time will be how fast the standard charger charges the

eBike’s lithium-ion battery

XiaoRui Liu

Control System Review Hassan Aftab

Control System Components

● 12 Volt DC latching solenoid

● Solenoid driver circuit

● Arduino Uno microcontroller

● Arduino Protoshield

● RC522 Mifare RFID reader/writer

● RFID swipe cards and access fobs

Hassan Aftab

Control Components Flow Chart

Microcontroller Solenoid Driver DC Latching Solenoid

RFID Sensor12 V DC Supply

Hassan Aftab

Solenoid Driver Schematic

Hassan Aftab

Microcontroller Pins Table

Hassan Aftab

Arduino Uno Input/Output Pins Function

Digital I/O 5 RFID RST - Reset control

Digital I/O 8 Output signal to solenoid driver

Digital I/O 10 RFID SDA - I2C-bus serial data line input/output

Digital I/O 11 RFID MOSI - SPI master out, slave in

Digital I/O 12 RFID MISO - SPI master in, slave out

Digital I/O 13 RFID SCK- SPI serial clock input

3.3 V RFID 3.3 V Input

GND RFID GND

Input/Output Pins Schematic

Hassan Aftab

Control System Test ResultsHassan Aftab

Microcontroller Testing

● Testing was done to ensure the Arduino Uno was full functionality

○ Board powered on when connected to power source (USB or DC source)

○ Ran various sample code sets and validated the results

○ Checked all input and output ports to ensure full functionality

○ Reset button functioned when pressed; system was reset

Hassan Aftab

RFID Module and Reader Testing

● RFID module was placed on the top right corner of the prototype station

● The RFID module is sensitive to the amount of distance in which it will read a

RFID card or fob (the closer the better)

● We found that when the card or fob is almost touching the RFID module is

when the system performs the best

● RFID module clearly detects which RFID card or fob is being used

● RFID cards and fobs are passive which can sometimes cause a delay in solenoid

retraction time; we believe switching to active tags in the future will fix this

Hassan Aftab

Solenoid Testing

● Connected DC latching solenoid to a 12V 2A DC

power supply

● The solenoid latch retracted and remained

retracted as long as power was being supplied

● The test was successful:

○ The solenoid retracted quickly

○ Default position was in the locked position

Hassan Aftab

Solenoid Driver Testing

● Constructed solenoid driver circuit and ran a basic blink program on the Arduino

Uno using an output pin to drive the solenoid

● The program provided a signal to the latching solenoid whenever LED1 on the

Arduino Uno microcontroller blinked

● Test successful; solenoid latch would retract whenever LED1 blinked and would

remain retracted in correspondence to the LED1 blinking frequency

● For example, if the LED1 blinking delay was set for 5 seconds, the latch would

remain compressed for 5 seconds before releasing

Hassan Aftab

Full Control System Testing

● When an RFID card or fob is swiped,

the solenoid will actuate allowing a

user to remove the eBike from the

station

● The station will only unlock for the RFID

cards or fobs that have been specified

in the code supplied to the

microcontroller

● The control system is fully functional

Hassan Aftab

Prototype DemonstrationJustin Hatcher

Project BudgetGabriel Sejas

Items Purchased

Gabriel Sejas

Project Budget Breakdown

Gabriel Sejas

● Control System: $221.73

● Charging System: $136.43

● Locking System: $89.10

● Total Spent: $447.26

ConclusionJustin Hatcher

Project Conclusion

● A fully functional charging and docking station was designed and prototyped

● All major goals of the project were achieved:

○ The station securely locks the eBike

○ The station efficiently charges the eBike

○ The station requires minimal user interaction

● The station provides a solid base in which more sophisticated station can be

built upon in the future

Justin Hatcher

Path Forward

● Weatherproofing of the station

● Aesthetically pleasing shell/cover

● Updated RFID module with active cards and fobs

● Cloud based user and eBike identification system

● Solar panel canopy

Justin Hatcher

Questions?