Fuel Cell Vehicle Team

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Fuel Cell VehicleTeam 5February 15th, 2007

• Critical Design Review for EE495B Capstone Senior
  Design

Faculty Advisor Dr. Jim Zhu Graduate Consultant
Tim Delashmutt

• Team Members
• Kyle Bray
• Brian Micochero
• Chuck Huizenga
• Tyler Thompson

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Overview of Major Changes

• We will not be implementing the computer control
  system on the full scale car this year, rather we
  will be testing our system on a prototype
  vehicle.

3
Need and Goal Statement

• Need
• The ammonia fueled vehicle has several subsystems
  that need to be controlled and coordinated these
  include ammonia electrolytic cell (AEC), the PEM
  fuel cell, battery pack, the motor controller,
  the motor, and the vehicle.
• Goal
• Develop an onboard computer to interface with
  each subsystem at the sensor and actuator level
  to enable on-demand hydrogen production and
  vehicle operation.

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Functional Flow Diagram,Levels 1 2
Central Drive Computer
Level 1
1.0 Operating System
The Operating System shall coordinate all tasks.
1.2 Execution of Software Modules
1.1 Initialization
Level 2
Program variables shall be initiated during
startup and hot reboots.
All software modules shall be executed in
real-time.
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Performance Requirements

• The prototype car shall run for 5 minutes without
  refueling.
• The prototype car shall be capable of running at
  a speed of 0.5km/hr.
• The fuel cell shall provide 10W continuously to
  the prototype vehicles components.
• The on-board micro controller shall be capable of
  receiving data from each sensor and manipulating
  each actuator within 20 milliseconds sampling
  time.

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Operational Requirements

• Digital display shall be provided
• Speed
• Voltage
• Current
• Critical system parameters, such as
• Flow rate
• Temperature
• Pressure
• The on-board microcontroller shall allow
  reprogramming of the control algorithms for the
  vehicle subsystems.
• The microcontroller shall have an emergency
  fail-safe stop procedure.

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Trade Studies Update

• Current Trade Studies
• LCD screen to display vehicle speed, motor
  voltage and current
• Hydrogen source for fuel cell
• Data acquisition devices (sensors)
• Motor Control
• Future Trade Studies
• Fuel Cell Sensors and Actuators
• Past Trade Study results
• Biscuit PCM-9375, 500 MHz, 1GB RAM
• PC104 CAN controller for Biscuit
• PIC 18F4431 for reading sensors and throttle
  control
• PIC 18F4682 for CAN communication to SBC
• I2C for onboard PIC to PIC communication

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Fuel Cell

• TECHNICAL SPECIFICATIONS
• 10-14W stack
• Number of cells 10
• Area 10 cm2
• Power 10W 6.5V, 14W 6V
• Reactants H2/air, reformate/air (airflow by
  convection)
• Temperature ambient-65C
• Pressure about 0-2 psi (hydrogen)
• Humidification self-humidified
• Cooling air (no cooling fans required)
• Weight (approx.) about 2.5 pounds
• Dimension (approx.) 8 cm x 7 cm x 7 cm
• Type of fuel cell PEM
• Flow rate at max output About 0.12 liter per
  minute hydrogen
• Start up time Instantaneous, load following
  Capability
• Efficiency of stack 50 at full power 

TALK ABOUT HYDROGEN SOURCE
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Communication

• CAN

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Computer

• Why did we pick the biscuit?
• I know we talked about this in the PDR, but
  mention it again

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LCD

• Display Speed, Motor Current, and Voltage
• Chose 1
• Larger charaters, reliable source, and multiple
  colors

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H-Bridge

• Why dont we use that circuit tim gave us?

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Current Sensor

• Types of current sensors
• Shunt Resistor (low or high side)
• Intrusive measurement
• Hall Effect Sensor
• High cost
• Current Transformer
• Only works with AC
• Low side shunt resistor method will be used due
  to low cost and good accuracy

Schematic of shunt resistor simulation
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Speed Sensor

• Speed Sensor Options
• Optical Encoder
• Quadrature Optical Encoder
• Hall Effect Encoder
• Measuring Vbemf
• Results
• Choose optical sensor with encoded disc machined
  by Chris (ME Grad)
• Cheap, we already had parts
• Easy to construct, 2 resisters, and a connector
  for the PIC
• Time, didnt have to wait on ordered parts

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Other Sensors

• Fuel cell stuff
• temp, pressure, flow rate, voltage, current, ect

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Hardware Design Details

• Model Car Chassis
• Platform for all components
• Circuit board w/ PIC 18F4431, 18F4682
• Low level data collection and actuation
• Biscuit PCM-9375
• Data logging through CAN protocol
• H-Bridge motor control
• Remote Control and Receiver

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Two PICS

• Why do we want two PICS?!?!?!?!

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Micro Controller Board

• Microcontroller board 3D preview and Schematic

PIC 1
PIC 2
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Wireless Receiver Demonstration

• This demonstrates our PIC code operating
• The fwd/rev and speed is sent from the controller
  (pictured)
• It is then received and processed by the PIC
• The PIC sends corresponding signals to the
  H-Bridge to run the motor

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Hardware/Software Interface Details
Steering Servo
Fuel Cell Actuators
Remote
Receiver
Motor
H-Bridge
Output PWM
18F4431
Speed Sensor
A/D Amplifier
Voltage Sensor
I2C
LCD screen
18F4682
Current Sensor
CAN
PCM-9375 (data logging)
Fuel Cell Sensors
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-Ilities

• Reliability
• Controller network shall yield expected results
• 85 success for a 10 minute test
• Controlled indoor lab conditions
• While still in development, current reliability
  is unknown
• Maintainability
• During development stages
• Designs lean and modular
• Code is very well documented
• Usability
• User must use joystick functions of remote control

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Safety Issues

• Electrical Shock (category III)
• Cause Irresponsibility
• Effect injury/death
• Preventative measures
• Dont work alone
• Double check connections
• Burns (category III)
• Cause excessive current through circuit
  components, exposure to ammonia.
• Effect injury/skin damage
• Preventative measures
• Exercise care when near ammonia
• Always know expected current before turning on
  power

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Part 2

• Requirements Compliance - show that the design
  satisfies the requirements

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Gannt Chart
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Resource Allocation Budget 500 Car Project
Funds

• Personnel 4 undergraduates
• Current personnel hours
• 1.7 FTE per person
• The team is currently spending 3 hours in
  meetings, 12 hours in the lab, and working about
  2 hours a week on individual research and
  studies.
• Estimated personnel hours to completion
• 2.0 FTE per person
• The team will probably spend extra time
  throughout the week on tests and data recording.

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• Bill of Materials for Microcontroller Board

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Risk Mitigation PlanRemoved
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Risk Mitigation Plan,Retired
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Risk Mitigation Plan,Retired
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Current Risks
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Project Issues

• H-Bridge Overheating
• Ordered H-Bridge chip
• Testing H-Bridge on other motors
• Behind of Schedule
• Working on to-date tasks as well
• Building sensors Speed, current, voltage
• Get Fuel Cell Specs
• Start working on Fuel Cell sensors and control
  system
• Put in extra hours on nights and weekends

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Summary

• Currently
• There was a major change to the project and we
  are now building a small prototype to test our
  system on.
• We are on schedule with only a few exceptions
• In the Future
• In the future we will install the fuel cell onto
  the prototype, finish building our controller and
  data acquisition board, and do trade studies and
  install various actuators and sensors
• Determine what controls and sensors fuel cell
  needs