Final Design ReviewFSAE Instrumentation

Ryan GunnJohn LeeDan Van WinkleAli Yilmaz

Formula SAE

Intercollegiate competitionNew car every yearCars designed for non-professional auto

cross racerOver 120 international teams

Operational Concept

Real time data capturePost ProcessingData analysis and reduction

Sensors

Shock Position SensorsSteering Position SensorAccelerometerWheel Speed SensorsOil Pressure SensorBrake Pressure SensorThermal Sensors

LF Wheel Speed

LF Shock Position

RF Wheel Speed

RF Shock Position

Engine Tach

Front Power and Signal

Conditioning Box

cRio

Rear Power and Signal

Conditioning Box

Unregulated 12V

RR Wheel Speed

RR Shock Position

LR Wheel Speed

LR Shock Position

Radiator Temperature

In

Oil Pressure

Break Pressure

Radiator Temperature

Out

Common

Steering Position

Front Sensors

LF Wheel Speed

LF Shock Position

RF Wheel Speed

RF Shock Position

Engine Tach

Front Power and Signal

Conditioning Box

cRio Unregulated 12V Common

Steering Position

Rear Sensors

cRio

Rear Power and Signal

Conditioning Box

Unregulated 12V

RR Wheel Speed

RR Shock Position

LR Wheel Speed

LR Shock Position

Radiator Temperature

In

Oil Pressure

Break Pressure

Radiator Temperature

Out

Common

Wheel Speed Sensors

Hall Effect SensorWheel SlipSpeed

Shock Position

Rotary Potentiometers

Shock lengthLoad on wheels

Pressure Transducers

Oil Pressure Design has been

questioned previously in competition

Brake Pressure Driver’s use of

brakes

Additional Sensors

Engine Tach Measured directly

from coil Square wave

Accelerometer 3 axis acceleration

Steering Position

Thermocouples

Heat exchange efficiency of radiator

PCB

Various power and signal conditioning circuits

Needed to be ruggedizedNeeded to be documentedNeeded easy to use software

Pspice Schematics

Pspice AC Sweep (cont)

Engine Tachometer

Front PCB Layout

Front Annotated

Front PCB Installed

Rear PCB Layout

Rear Annotated

Rear PCB installed

Parts ListPart Digikey # Manufacturer Manufacturer # Qty

Cost per unit

Cost per part

0.1 μf BC1148TR-ND Vishay K104Z15Y5VE5TL2 2 $0.07 $0.13

0.15 μf BC1079TR-ND Vishay K153K15X7RF5TL2 1 $0.02 $0.02

0.22 μf BC1112TR-ND Vishay K223K15X7RH5TL2 2 $0.15 $0.30

1 μf BC1151TR-ND Vishay K105Z20Y5VE5TL2 3 $0.18 $0.53

10 μf 718-1212-ND Vishay 199D106X9010B1V1E3 5 $0.95 $4.75

100 μf 199D104X9035A2V1E3-ND Vishay 199D104X9035A2V1E3 10 $0.21 $2.10

2.6V regulator 296-11117-5-ND Texas Instrument UA78L02ACLP 1 $0.40 $0.40

10V regulator KA78L10AZTA-ND Fairchild KA78L10AZTA 4 $0.10 $0.38

3 pin terminal 277-1274-ND Pheonix Contact 1725669 1 $1.81 $1.81

6 pin OSTVN06A150-ND Pheonix Contact OSTVN06A150 12 $0.71 $8.50

2 pin terminal 277-1247-ND Pheonix Contact 1729128 3 $0.83 $2.49

10K Resistor RC1/410KKR-ND Stackpole RC 1/4 10K 10% R 6 $0.12 $0.73

220 Resistor RC1/4220JR-ND Stackpole RC 1/4 220 5% R 2 $0.13 $0.26

680 Resistor RC1/4680KR-ND Stackpole RC 1/4 680 10% R 2 $0.12 $0.24

1k Reistor RC1/41KKR-ND Stackpole RC 1/4 1K 10% R 3 $0.12 $0.37

20K Resistor RC1/420KJR-ND Stackpole RC 1/4 20K 5% R 1 $0.13 $0.13

Amp AD8620AR-ND Analog Devices AD8620AR 1 $15.51 $15.51

Diode 1N5240BFSTR-ND Fairchild 1N5240BTR 1 $0.08 $0.08

Switch EG1889-ND E-Switch RR3130ABLKBLKFS 1 $3.48 $3.48

Software Requirements

Debug existing software

Improve functionality

Write documentation

Software Improvements

Boot fileSwitchTimestampUSB StorageNo intermediate step

Software Improvements - Boot File

The logging program will be loaded in the memory on startup

No need to connect a computer to start logging

Faster and easier use of the system

Software Improvements - Switch

Added functionality to turn it on/off with a switch

The switch will stop logging when the run is done

It will start logging again with a new log file

Software Improvements - Timestamp

Log files were named cRIO_Log.datAdded functionality to create a different

filename for every runFilename includes date and timeEasier to identify filesNo risk of overwriting old log files

Software Improvements – USB Storage

Added functionality to store files on a USB drive

Not limited to 128 MB on the cRIOCan support up to 4 GBEasier to transfer files to the computer

Software Improvements – No Intermediate Step

Got rid of intermediate step in reading log files

Used to have two programsOne to convert binary files to measurement

filesOne to read the measurement files

Combined the two into one programEasier to read the log files

Data Flow

Data Flow

Data Flow (FPGA)

“FPGA – Buffered DAQ with DMA.vi”Set up analog and digital channels for

acquisitionRead in data from input channels

Store in AI data cluster data structure (Real Time)

Store in DMA FIFO data structure (Logging)

Data Flow

Data Flow (cRIO)

“RT – Logging & RT.vi”Open FPGA reference from previous stepReal Time

Read in AI data cluster data structureSplit clusters into component signalsPerform calculations on raw data from

sensorsDisplay data to the end user

Data Flow (cRIO) (cont’d)

Data Flow

Data Flow (cRIO) (cont’d)

Logging:Calibration of channels stored on cRIOCalibrate channels .xml fileRead in FIFO data structure .dat file

Data Flow (cRIO) (cont’d)

Data Flow

Data Flow (PC)

“Windows – Read LVM file.vi” Option to convert binary data files to .lvm file Open .lvm file Split signals from .lvm file to component

waveforms Perform calculations on raw waveforms from

sensors Display data to the end user

Data Flow (PC) (cont’d)

Recommendations

Digital signal processingImprove modularityAdditional power sourceCode simplification for improvement of

real-time data streamPost run statistic breakdown