Transcript Presentation

FSAEe
Data Acquisition System
ECE 445 Senior Design
Mohan Sha
Raviraj Mahajan
Mohammad Farooq Shaik
TA: Ryan May
Project No. 34
Spring 2013
Introduction
• Motivation
- Formula SAEe needs DAQ system
• Objective
- Real time display of sensor data to driver
- Wireless display of data to pit crew
- Store data for crew
Features
• Optimum response time of the sensors
• Data stored directly into excel sheet with time
stamp
• Tested wireless range spans over 350 meter
radius
System Overview
Schematics
Tx unit
Schematics
Rx unit
System Components
• Hardware
- Power Supply
-
Microcontroller Unit – Arduino Uno
XBee Pro Series 1
LCD
5 Sensors
• Software
- Arduino Programming Environment
- Configurable with PC
Power Supply
300V to 24V to 12V provided
5V required for:
- Microcontroller
- Sensors
- LCD
12V to 5V dc-dc conversion
Power Supply
Input Voltage: 12V
Output Voltage: 4.91V
Duty cycle 0.416
Voltage ripples: 20mV
Tolerance < 2%
PCB Design for buck converter
Data
• On-board LCD display (for driver):
– Vehicle speed
– Motor temperature
• Wireless transmission to pit crew:
–
–
–
–
–
Vehicle speed
Motor temperature
Motor speed
Battery voltage
Coolant temperature
Motor Temperature Sensor
-
Analog
5.0V input
oC = 100V-50
±2oC in -40 to 125oC
Motor Temperature Sensor
Output Voltage vs. Temperature
Documented
Observed
Motor Temperature Sensor
Thermometer
Temp.(°C)
25.1
40.25
55.42
75.22
90.21
100.02
Sensor Temp. (°C)
27.7
44.01
57.7
77.91
93.2
102.88
Average Error = ~ 5%
= 3 oC
Sensor Temperature vs. Thermometer Temperature
Coolant Temperature Sensor
-
Digital one-wire
Waterproof
5.0V input
±2oC in -55 to 125oC
Coolant Temperature Sensor
Thermometer
Temp.(°C)
25.55
40
55.5
75.25
90.35
100.25
Sensor Temp. (°C)
23.1
37.5
52.88
73.15
87.75
97.89
Average Error = ~ 5%
= 2.45 oC
Thermometer Temperature vs. Sensor Temperature
Speed Sensor
• Wheel and motor speed
-
Hall Effect
-40oC to +150oC
5V input (1kΩ pull up resistor)
10µs rise/fall time
Maximum speed 10kHz
• Target
-
Magnet or magnetic metal
Tooth height: 0.2 in
Tooth width: 0.1 in
Tooth separation: 0.4 in
Tooth thickness: 0.25 in
Speed (Hall Effect) Sensor
Speed (Hall Effect) Sensor
Stroboscope
Reading (RPM)
80
110
140
170
200
230
Sensor Reading (RPM)
68
120
155
165
225
212
Average Error = ±16 RPM
Stroboscope RPM vs. Sensor RPM
Arduino Uno
Arduino Uno:
• Atmel ATmega328 microcontroller
• 14 Digital I/O Pins
• 6 Analog Pins
• 16 MHz speed
• Voltage required: 5 V
• Supplies 3.3V as required for Xbee
Xbee and XBee Explorer USB
XBee Pro 60mW Wire Antenna - Series 1:
• Range: 1 km
• Observed Range: 350 m
• Voltage Required: 3.3 V
• Max data rate: 250kbps
Xbee Explorer USB:
• Transmit data received by Xbee over USB through Serial interface
• Gobetwino software
DAQ System
Achievements
•
•
•
•
All required sensor data acquired
Data successfully transmitted over XBee
Data stored in Excel sheet
All components successfully powered by a
dc-dc converter circuit
Difficulties
• FIO
• BMS data acquisition
• Soldering extremely small surface mount chips
(4 mm sized with 8 pins)
Further Improvements
• Collect and display more data
- Steering Wheel Position Sensor
- Tire Pressure Sensors
- Lap time recorder
• Improve wireless range and reduce sensor output
error.
• More efficient PCB design
• Integrate communication with Battery Monitoring
System to read additional data
Special Thanks:
Prof Scott Carney
TA Ryan May
ECE Parts shop staff
Questions?