Transcript Outline for John - Electrical and Computer Engineering Department

Bradley University Electrical Engineering Department
SAE Formula Car
Data Acquisition & Display System
April 9, 2015
Advisor : Professor Steven Gutschlag
Ahmed Albitar
John Gertie
Justin Ibarra
Sean Lenz
Agenda
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Problem statement
Background
System block diagram
Division of labor
Project non-functional requirements
Project functional requirements
Discussion of individual contributions
System test results
Summary & conclusion
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Problem Statement
Every year the Mechanical Engineering department at Bradley University designs
and constructs a formula racing car. Past performances have proven to be
inconsistent due to engine failures and structural breakdowns. To improve future
performance, an advanced data acquisition system will be employed to indicate
problems before a failure occurs. Unlike the existing system, data will be
monitored by both the driver and the crew. A touch screen mounted in the vehicle
will display data and warning signals to the driver. The same data will also be
transmitted to a computer, where it will be recorded for diagnostic evaluations.
Multiple indicators will be used to warn the driver and crew if data readings exceed
a safe limit.This system will provide the necessary information to optimize the
formula cars performance, giving Bradley’s mechanical engineering department
an edge over the competition.
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Problem Description
• Acquire 5 Key data values from SAE Formula Car
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RPM
Speed
Oil Pressure
Water Temperature
Battery Voltage
• Aggressive Notification system to alert driver if data exceeds
threshold values
• Multi-mode touch screen display
• Wireless transmission of data to off-track computer
• Data Logger
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Background
• Design goals
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Aesthetically pleasing
Economically viable
Race ready performance
User friendly for all levels
• '07-'10 Honda CBR600RR engine
• Total budget of $10,000
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System Block Diagram
5V Power
Supply
Sensors
UART
Amulet LCD
UART
Wireless
Transceiver
Microcontroller
(ATmega128)
RS-232
Laptop
(LabVIEW
GUI)
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Division of Labor
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Ahmed
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Sensor selection & interfacing
Justin
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Amulet display
Justin & John
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Interface microcontroller with HyperTerminal
Test microcontroller with simulated sensor data
Interface microcontroller with LabVIEW
Sean
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Prepared LabVIEW to receive wireless data
Interface microcontroller with Amulet
Setup external power supplies for the microcontroller, Amulet, and Op-Amps
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System Block Diagram
5V Power
Supply
Sean
Ahmed
UART
Amulet LCD
Microcontroller
Sensors
John & Justin
(ATmega128)
UART
Wireless
Transceiver
RS-232
Sean
Laptop
(LabVIEW
GUI)
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Project Non-functional Requirements
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Project Functional Requirements
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Ahmed's Agenda
• Subsystem block diagram
• Pressure and Temperature Sensor Circuitry
• Project functional requirement and specification
• Sensors
• Test result
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Subsystem Block Diagram
Temperature Sensor
Pressure Sensor
Engine
12V
RPM Sensor
ATmega128
Velocity Sensor
Voltage
Measurement
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Pressure and Temperature Sensor Circuitry
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Functional Requirements and specification
• 12 volts from the car's battery
• Water temperature measured by a temperature sensor
• Oil pressure measured by a pressure sensor
• Velocity and RPM measured by a speed sensor
• Data acquisition maximum error of 5%
• Sensors compatible with engine
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Temperature Sensor
• ProSense TTD25N-20-0300F-H
• Analog output: 4 to 20mA
• Operating Voltage: 10 to 30VDC
• Temperature range: 0-300 F
• ¼ NPT
• Cable : CD12L-0B-020-A0
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Pressure Sensor
• ProSense PTD25-20-0100H
• Analog output: 4 to 20mA
• Operating Voltage: 9.6 to 32VDC
• PSI range: 0 to 100
• ¼ NPT
• Cable : CD12L-0B-020-C0
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RPM and Velocity Sensor
• Supply Voltage: 4.5 - 24 V DC
• Supply Current: 10 mA
• Output Signal: Pulse 0-50 V
• Maximum output current: 20 mA
• Sensing distance: From 0.5 to 2 mm
• Maximum operating Frequency: 100KHz
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Temperature Sensor Result
• Maximum 5% error
• T = m × Io +k
• m = 10418.75
• k = -59.48 C
• Linear Sensor
• V = Io × Rf (Rf=250 ohms)
T= temperature
m = slope
k = Temperature offset
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Pressure Sensor Result
• Maximum 5% error
• P = m × Io +k
• m = 6250
• k = -25 C
• Linear Sensor
• V = Io × Rf (Rf=250 ohms)
P = Pressure
m = slope
k = pressure offset
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RPM Sensor Result
• Maximum 5% error
• F = Frequency
• RPM = F(cycle/sec) (60sec/1min) (1rev/2cycles)
• Linear Sensor
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Justin’s Agenda
• Subsystem block diagrams
• Project functional requirements
• Hardware and software used
• Amulet touch screen
• Subsystem test results
• Wireless transmission
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Subsystem Block Diagrams
Water Temp Input
Amulet Touchscreen
Home Page
Oil Pressure Input
Demo Mode
MPH Input
Practice Mode
Aerocomm
AC4790
RPM Input
Race Mode
Batt. Voltage Input
ATmega128
ATmega128
Aerocomm
AC4790
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Project Functional Requirements
• Functional Requirement
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Data acquisition sends data for
display
Display accessible to driver
• Specification
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Data can viewed on the
touchscreen
Can be easily seen by driver
without posing as a distraction
from driving
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Hardware and Software Used
• Hardware
• Amulet touchscreen
• Laptop
• Atmega128
• Software
• Gemstudio
• Atmel Studio
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Amulet Touchscreen
• Pseudo data used for demo mode
• Aggressive warning system
• Demo mode sweep
• Navigation between modes
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Amulet Display Results
• Aesthetics
• Navigation
• Widgets
• Microcontroller communication
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Home Page
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Practice Mode
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Demo Mode
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Demo Mode
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Race mode
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John's Agenda
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Subsystem block diagram
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Project functional requirements
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Hardware & software used
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Wireless transmission testing
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Testing with simulated data
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Interfacing with LabView
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Subsystem test results
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Subsystem Block Diagram
Water Temp Input
Oil Pressure Input
MPH Input
RPM Input
Aerocomm AC4790
LabVIEW Display
Batt. Voltage Input
ATmega128
Aerocomm AC4790
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Project Functional Requirements
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Hardware & Software Used
Hardware
Software
• Atmega128
• Aerocomm AC4790
• Laptop
• Atmel Studio
• HyperTerminal
• LabVIEW
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Wireless Transmission Testing
• Board to board
• Board to HyperTerminal
• Microcontroller to HyperTerminal
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Testing with Simulated Data
• Linear Output
• Oil Pressure, Water Temperature, Battery Voltage
• Simulated with Power Supply
• Pulse Output
• Tachometer, Speedometer
• Simulated with the Wave Generator
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Interfacing with LabView
• Communication Protocol
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Universal Asynchronous Receiver/Transmitter(UART)
• Transmission Type
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Ascii
• Sent using packets
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Subsystem Test Results
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Wireless communication established
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Microcontroller communication with HyperTerminal
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Data displayed is current
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Values displayed in ascii equivalent
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Sean’s Agenda
• Functional requirements
• Subsystem block diagram
• Equipment used
• Interface Amulet with microcontroller
• Prepare LabVIEW to display wireless data
• Results
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Functional Requirements & Specifications
Functional Requirements
Specifications
Display data to driver and pit crew
Touchscreen display
Store data for review
UART communication
Does not interfere with driver
performance
5 V power supply
No loose or exposed wires
Display real time data
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Subsystem Block Diagram
5V Power
Supply
Microcontroller
(ATmega128)
Data From
Wireless
Transceiver
UART
RS-232
Amulet LCD
Laptop
(LabVIEW
GUI)
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Hardware & Software
Equipment
Software
• Amulet LCD
• GemStudio Pro (Amulet display
software)
• ATmega128 (microcontroller)
Studio 6.1 (microcontroller
• DC/DC converter (±5 𝑉 , ±15 [𝑉]) • Atmel
software)
• Level shifter (+5 [V] to +3.3 [V])
• LabVIEW 2014
• Laptop
• Oscilloscope
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Amulet Subsystem Bl0ck Diagram
5V Power
Supply
Microcontroller
Put Sensor
Data in Array to
Transmit
Send Data
Array
UART
Amulet
Touchscreen
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Amulet LCD
• Serial Protocol
• UART
• Ascii
• 9600 bps baud rate
• Transmit specific protocol to access variables
• Microcontroller is master
• Initializes communication
• Amulet is slave
• Full Protocol- Responds only if Amulet receives valid message
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Amulet LCD
• Internal RAM (IR) is memory on the Amulet.
• 256 byte variables
• 256 word variables (word = 2 bytes)
• Can receive 14 different command messages from microcontroller
• Can access internal RAM on Amulet
• Changing and copying variables
• Jump to different pages on display
• Draw pixel, line, or box
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Amulet Serial Communication Flow Chart
Op-code = Tells Amulet what type of variable is being accessed (byte or word)
Address = The variables location on the RAM of the Amulet LCD
Value
= The data to be displayed on the Amulet LCD
Op-code
Variable
Address
(High nibble)
Variable
Address
(Low nibble)
Variable
Value
(High nibble)
Variable
Value
(Low nibble)
Figure 1 – Transmit protocol for a byte variable.
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LabVIEW Subsystem Bl0ck Diagram
Put Sensor
Data in
Transmission
Array
Send Array
Data
RS-232
LabVIEW
I/O Assistant
(Parse Data)
LabVIEW
Gauge Display
Log Data
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LabVIEW Display
• Serial Protocol
• RS-232
• Ascii
• 9600 bps baud rate
• Transmit packets of data
• Instrument I/O Assistant
Aerocomm
Transceiver
Laptop
(LabVIEW
Display)
Instrument
I/O
Assistant
• Front Panel vs. Block Diagram
• Connect blocks to data type
and viewing method
Display
Data
Save Data
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Front Panel
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Serial Communication Setup
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Block Diagram
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Subsystem Results
• Successful interface between ATmega128 and Amulet LCD
• Data sent and displayed on the Amulet LCD
• Successful interface between Aerocomm Transceiver and
LabVIEW GUI
• Data sent, displayed, and stored on the LabVIEW GUI
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System Test Results
• Display data to driver with aggressive notification system
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Race, demo, and practice modes
• Wirelessly send data to pit crew’s laptop to be displayed on
LabVIEW
• Data logged via LabVIEW
• Sensor’s acquire data with max error under 5%
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Summary & Conclusion
• BU ME’s require more advanced notification system for driver
• Requires data logging, multiple display modes, and wireless transmission
• System is functional
• Requires installation and further testing
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Sources
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http://cegt201.bradley.edu/projects/proj2011/pjacher/SAEDAQ/Deliverables_files/SAEDA
Q_final_report.pdf
http://www.atmel.com/images/doc2467.pdf
http://www.amulettechnologies.com/images/stories/Downloads/mk480272cdatasheet111
2.pdf
https://www.dropbox.com/s/l8abp41iru83oqg/Datasheet_carspd_eng_101.pdf?dl=0
http://www.automationdirect.com/static/specs/prosensettrans.pdf
http://www.automationdirect.com/static/specs/prosensetransmitters.pdf
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Appendix
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Initialization
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ISR
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.C/.h files
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to_ascii
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Amulet Ascii Transmit Protocol Example
Microcontroller
Set Byte Variable
Amulet Response
Microcontroller
Set Word Variable
Amulet Response
Figure 2 – Serial communication flow chart
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Amulet Protocol Ascii
Example: microcontroller sets internal RAM (IR) word variable to
specific value (0x02C9)
Figure 3 – Serial communication flow chart
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UART Transmit
• 1V per division
• 0.5ms per division
• Transmission contains:
{0x00, 0xD6, 0x31}
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Maximum data log time
• Limited by max rows in excel
• Max rows about 1 million
• Log data every 100 [ms]
• Max time = 27.8 hours
• 0.1 [sec/row] *1.2E6 [rows] = 100,000 sec
• 100,000 [sec] /60 [sec/min] /60 [min/hr] = 27.8 hrs
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Max Transmission Rate with 9600 bps Baud Rate
• 1 bit sending time:
• 1/9600 = 104 us
• Assume 16 byte packet
• 8 bits + 1 start_bit + 1 stop_bit = 10 bits/byte_sent
• 104 [us/bit] * 10 [bits/byte] * 16 [bytes/packet] = 16.6 [ms/packet]
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Research
• Amulet serial communication protocol
• LabVIEW Instrument I/O Assistant
• Troubleshooting errors
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