presentation #3
TRANSCRIPT
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?