FSAE Instrumentation 1/27/09

Ryan GunnJohn LeeDan Van WinkleAli Yilmaz

Formula SAE

Intercollegiate competitionNew car every yearCars designed for non-professional auto

cross racerOver 120 international teams

FSAE Competition Scoring

Data Acquisition System

Tuning is importantDriver feedbackQuantitative baseline

Support design decisionDriver evaluation

Operational Concept

Real time data capturePost ProcessingReal time data transmission*Simultaneous data capture and

transmission* Data analysis and reductionNew/additional power sources**Goals

Flow of Data in Hardware

Sensor Selection

Shock Position SensorAccelerometerWheel Speed SensorOil Pressure SensorSteering Position Sensor

Sensor Selection

Sensor Type Sensor Selected Requirement Specification Shock Position Novotechnik 2841

S0002 <30º angular rotation detection

100º angle range

Acceleration Analog Devices ADXL330

±3g 4 axis

±3g 4 axis

Wheel Speed Automation Direct PD1-AN-1A

<600 Hz 5000 Hz

Oil Pressure Omega PX32B1 <200 psi 2500 psi Steering Position Novotechnik SP2801

A502 <180º angular rotation

310º angle range

DAQ Requirements

DAQS Options

MoTecAIM SportsNational Instruments cRIO

Motec

Pros:Ease of installationUser Friendly GUI

Cons:High cost ($4000-$6000 for data logging

unit)Limited to Motec sensorsLocked software

AIM Sports

Pros:Cheaper than MotecMore, cheaper sensors available than

MotecCons:

Price (~$2000)Locked software

NI cRIO

Pros:No cost for DACS or sensorsChangeable LabVIEW codeModular Customizable

Cons:Programming

Notes

All options provided:Weight requirementFree tech support Free software

Decision

NI cRIO is best choice for this application

Cost is a critical factorPerformance/accessibility factors can be

worked on

Wireless Transmission

Daniel Alford, “Light Weight, Low Cost, Automotive Data Acquisition and Telemetry System" (MS thesis, University of Cincinnati, 2005)

“The testing performed shows that the wireless networking technology does not adversely affect the data being transferred”

Standard antenna not well suited (range) Line of sight issues are the major problem

Decision

Wireless data transmission will not initially be pursuedData logging issuesDependabilityTime constraints

Power Consumption

cRIO-20WAccelerometer 180 μA - 2.52 mWOil Pressure - 40mWBrake Pressure – 25mWRotary Potentiometer – 0.7mW Proximity Sensor – 200mW Total ~300mW ~1.8 Amperes

Comparing Batteries

Current Battery ODYSS PC310Drycell

2.87 AH/kg8 AH

Possible AlternativesLi Ion

11.4 AH/kgStringent charging requirements

Accomplished Tasks

Installed software toolsEstablished connection with the cRIOUpdated software on cRIOTested real-time monitoringTested data logging

Real-time Monitoring

Significant lagRequires constant connection to car

(Requires wireless)Useful for testing sensors and data

acquisition codeCannot log data simultaneously (Memory

issues)A nice to have

Testing Real-time Monitoring

Data Logging

Currently must be connected to computer Switch to turn on and off Boot file

More complex process than real-time monitoring

Allows for future analyzing of data

Testing Data Logging

Testing Data Logging

Testing Data Logging

Instructions Created

List of all modules necessary to run software

How to connect to the cRIO