Preliminary Design ReviewPreliminary Design Review30 January 200730 January 2007

Black Box Car System (BBCS)Black Box Car System (BBCS)ctrl + z:ctrl + z:

Benjamin Baker, Lisa Furnish,Benjamin Baker, Lisa Furnish,Chris Klepac, Benjamin Mauser,Chris Klepac, Benjamin Mauser,

Zachary MiersZachary Miers

MotivationMotivation

Car accidentsCar accidents Provide proof of who was at faultProvide proof of who was at fault Provide information about force of crashProvide information about force of crash

Other traffic incidentsOther traffic incidents Capture information about what really Capture information about what really

occurred if ticketed for speeding, occurred if ticketed for speeding, following, etc.following, etc.

Concept of Operations:Concept of Operations:GoalsGoals

Provide visual information of car’s surroundings for Provide visual information of car’s surroundings for period of time before accidentperiod of time before accident

Use accelerometer to determine if accident has Use accelerometer to determine if accident has occurredoccurred If programmed acceleration level occurs, BBCS knows a If programmed acceleration level occurs, BBCS knows a

crash has occurredcrash has occurred Force reading will be saved in conjunction with visual dataForce reading will be saved in conjunction with visual data

Removable storageRemovable storage Crash video can be viewed on home computerCrash video can be viewed on home computer

AutonomousAutonomous In event of accident, data automatically savedIn event of accident, data automatically saved Powered by vehiclePowered by vehicle

CONOPS:CONOPS:RequirementsRequirements

Performance RequirementsPerformance Requirements

Video requirementsVideo requirements - Camera outside of vehicle- Camera outside of vehicle- 5-20 seconds video recording loop5-20 seconds video recording loop- 1-5 frames per second1-5 frames per second

Data storageData storage - Video loop written to RAMVideo loop written to RAM- In event of accident, data from In event of accident, data from each camera written to Flash each camera written to Flash memorymemory

User interfaceUser interface - Ability to view video of crash on Ability to view video of crash on home computerhome computer- LED indicator if data has been LED indicator if data has been storedstored- Ability to manually store/erase Ability to manually store/erase datadata

Block Diagram: Block Diagram: MainMain

Black Box

Camera

User interface

Storage

Reset

Accelerometer

Block Diagram:Block Diagram:Black BoxBlack Box

Main Processor

ICLED

IC

CameraIC

CameraRAM

FlashStorage

Computer

Accelerometer

Reset Power

LCDor

Implementation:Implementation: MicrocontrollerMicrocontroller

Flash-based, 16/32-bitFlash-based, 16/32-bit ARMARM Microchip PICMicrochip PIC MSP430MSP430

Re-programmableRe-programmable On-board ADC, UART, I²C, Timer/counterOn-board ADC, UART, I²C, Timer/counter Interface to sensors, Flash data logInterface to sensors, Flash data log USB 1.0/2.0 capableUSB 1.0/2.0 capable

Implementation:Implementation:MicrocontrollerMicrocontroller

One main processor to act as a central One main processor to act as a central processor to control all coprocessorsprocessor to control all coprocessors Video processors, memory, accelerometer, Video processors, memory, accelerometer,

etc.etc. Our design will use one processor for Our design will use one processor for

each camera moduleeach camera module This will allow us to more easily implement This will allow us to more easily implement

several video sources if extendedseveral video sources if extended

Implementation:Implementation:VideoVideo

We’re looking to use either a CCD or We’re looking to use either a CCD or CMOS camera as our video sensor.CMOS camera as our video sensor.

Ideally we would like to use a camera Ideally we would like to use a camera with USB output and onboard with USB output and onboard compression.compression.

Using a webcam oriented device, we’re Using a webcam oriented device, we’re hoping to eliminate any need to program hoping to eliminate any need to program USB drivers. With a corresponding USB USB drivers. With a corresponding USB microcontroller, this might be possible.microcontroller, this might be possible.

Implementation:Implementation:VideoVideo

Camera – STVS6522Camera – STVS6522 AdvantagesAdvantages

Only needs a 5V supplyOnly needs a 5V supply Large range on input voltage (4.1-5.6)Large range on input voltage (4.1-5.6) Adjustable Frame RateAdjustable Frame Rate Black and White or Color imagesBlack and White or Color images USB 2.0 compliantUSB 2.0 compliant Field of depth is infinite with a fixed focusField of depth is infinite with a fixed focus

Implementation:Implementation:VideoVideo

DisadvantagesDisadvantages Operating range isn’t ideal for a full Operating range isn’t ideal for a full

automotive design (32-104 F automotive design (32-104 F °°)) Minimum focus is 20 cm (~8 in)Minimum focus is 20 cm (~8 in)

Implementation:Implementation:Video CompressionVideo Compression

We assume we are getting raw video We assume we are getting raw video from an un-compressed CMOS from an un-compressed CMOS cameracamera

Estimated needs:Estimated needs: Moving JPEG conversionMoving JPEG conversion Real time video compression (at Real time video compression (at

least fast enough to convert the first least fast enough to convert the first frame by the time the second frame frame by the time the second frame is taken)is taken)

Implementation:Implementation:Video CompressionVideo Compression

Raw CCD Data

Buffered Storage

IC for Video Processing

I2C or USB to main IC Storage for video processing

Implementation:Implementation:Video CompressionVideo Compression

Video Conversion TypesVideo Conversion Types Digital Camera CoprocessorDigital Camera Coprocessor IC Programmed to do video compressionIC Programmed to do video compression

Ideal Setup:Ideal Setup: CMOS Digital Camera coprocessor for digital CMOS Digital Camera coprocessor for digital

still and web camerasstill and web cameras Real time video conversion with 50:1 Real time video conversion with 50:1

compression ratiocompression ratio I2C or USB data outputI2C or USB data output

Implementation:Implementation:Video CompressionVideo Compression

Suppliers:Suppliers: STMicroelectronicsSTMicroelectronics MotorolaMotorola BeyondLogicBeyondLogic Digi-KeyDigi-Key

Implementation:Implementation:MemoryMemory

Fast re-writeable memory to buffer image Fast re-writeable memory to buffer image data.data. SRAMSRAM

Advantages Advantages Programming simplicityProgramming simplicity Control simplicityControl simplicity

DisadvantagesDisadvantages ExpensiveExpensive Limited sizeLimited size

RequirementsRequirements Capable of handling 5 frames/sec video inputCapable of handling 5 frames/sec video input Low power consumptionLow power consumption

Implementation:Implementation:MemoryMemory

Slow large capacity memory for image Slow large capacity memory for image data storagedata storage FlashFlash

AdvantagesAdvantages RobustRobust CheapCheap

DisadvantagesDisadvantages Slow access speedSlow access speed

RequirementsRequirements Compact Flash interfaceCompact Flash interface

Implementation:Implementation:CommunicationCommunication

Ideal SolutionIdeal Solution I2CI2C USB 2.0 / 1.0USB 2.0 / 1.0

FallbackFallback Several I/O ports Several I/O ports

Implementation:Implementation:AccelerometerAccelerometer

We’re looking at using a MEMS based We’re looking at using a MEMS based accelerometer to detect a crash.accelerometer to detect a crash.

The accelerometer is the central The accelerometer is the central trigger for the system.trigger for the system.

The entire black box is in a looping The entire black box is in a looping state until the accelerometer state until the accelerometer interrupts and sets the system into interrupts and sets the system into its crash procedure.its crash procedure.

Implementation:Implementation:AccelerometerAccelerometer

Accelerometer - LIS3LV02DQAccelerometer - LIS3LV02DQ AdvantagesAdvantages

3 axes (crash from above?)3 axes (crash from above?) II22C/SPI output interfaces directly with C/SPI output interfaces directly with

MicrocontrollerMicrocontroller Factory calibrated with offsets loaded on Factory calibrated with offsets loaded on

startupstartup Variable sampling frequencyVariable sampling frequency

Implementation:Implementation:AccelerometerAccelerometer

DisadvantagesDisadvantages 2.5 V operation (increasing complexity 2.5 V operation (increasing complexity

with power supply)with power supply) Configurable to +/- 2 or 6 gsConfigurable to +/- 2 or 6 gs Might trigger too easilyMight trigger too easily

Implementation:Implementation:PowerPower

We assume we are getting power from We assume we are getting power from a car battery that varies from 8-16V. a car battery that varies from 8-16V.

Estimated needs:Estimated needs: One 12V-1A converter for cameras and One 12V-1A converter for cameras and

sensorssensors One 5V-5A and a 3.3V-5A converter for One 5V-5A and a 3.3V-5A converter for

processors, memory, and other circuitryprocessors, memory, and other circuitry

Implementation:Implementation:PowerPower

Car Battery(8V-16V)

12V-1A Converter 5V-5A Converter 3.3V-5A Converter

Cameras, Sensors, Etc.Processors, Memory,

Other Circuitry3.3V Processors and

Circuitry

Implementation:Implementation:PowerPower

Supply Types Available:Supply Types Available: Linear Voltage RegulatorsLinear Voltage Regulators Switching ConvertersSwitching Converters

Ideal Setup:Ideal Setup: 12V-1A, buck-boost12V-1A, buck-boost 5V-5A, buck5V-5A, buck 3.3V-5A, buck3.3V-5A, buck

Implementation:Implementation:PowerPower

Designing the SupplyDesigning the Supply Hard way: Design it by hand, go through Hard way: Design it by hand, go through

plenty of equations, and have a less plenty of equations, and have a less efficient converter than one you can buy efficient converter than one you can buy for cheap.for cheap.

Easy way: Go to National Semiconductor, Easy way: Go to National Semiconductor, go to the Power Webench, type in your go to the Power Webench, type in your input voltage and your output voltage input voltage and your output voltage and current and it designs it for you.and current and it designs it for you.

Implementation:Implementation:PowerPower

The result for a 12V-1A Supply:The result for a 12V-1A Supply:

Implementation:Implementation:PowerPower

Suppliers:Suppliers: National SemiconductorNational Semiconductor Texas InstrumentsTexas Instruments STMicroelectronicsSTMicroelectronics Analog DevicesAnalog Devices Many, many othersMany, many others

Implementation:Implementation:User InterfaceUser Interface

Ideal SolutionIdeal Solution Plug into computer and all video sources Plug into computer and all video sources

show up and start to runshow up and start to run On-station displays (LCD or LED on box)On-station displays (LCD or LED on box)

FallbackFallback Data display in Windows Application (Excel, Data display in Windows Application (Excel,

Visual Basic, etc.)Visual Basic, etc.) Data dump to HyperTerminal convert video Data dump to HyperTerminal convert video

using program then view video sourcesusing program then view video sources

Implementation:Implementation:EnclosureEnclosure

Ideal SolutionIdeal Solution Custom Plexiglas enclosureCustom Plexiglas enclosure

WeatherproofWeatherproof Transparent (for Expo)Transparent (for Expo) Strong and Shock resistant (protect equipment in Strong and Shock resistant (protect equipment in

the event of collision)the event of collision) Fallback SolutionFallback Solution

Generic electronics enclosureGeneric electronics enclosure Locking metal boxLocking metal box Some foam to lessen shockSome foam to lessen shock

Contingency PlanContingency Plan

No video altogetherNo video altogether Instead, base system around inputs of Instead, base system around inputs of

speed, acceleration, braking, blinkers, speed, acceleration, braking, blinkers, lights, etc. directly from carlights, etc. directly from car

ExtensionsExtensions

Other sensorsOther sensors SpeedSpeed Lights, blinkers, brakesLights, blinkers, brakes GPSGPS

Four video sources instead of oneFour video sources instead of one 25fps, 30 second video loop25fps, 30 second video loop

TestingTesting

Skateboard with system attached to itSkateboard with system attached to it

Push skateboard into wall (collision)Push skateboard into wall (collision) Kick skateboard (side collision)Kick skateboard (side collision) Drop basketball on top of car (falling rocks)Drop basketball on top of car (falling rocks) Hold bacon behind car (Cop with false Hold bacon behind car (Cop with false

ticket)ticket)

Division of LaborDivision of Labor

Video: Chris KlepacVideo: Chris Klepac Compression: Zach MiersCompression: Zach Miers Power: Ben BakerPower: Ben Baker Accelerometer: Chris KlepacAccelerometer: Chris Klepac Microcontroller and misc. sensors: Lisa Furnish & Microcontroller and misc. sensors: Lisa Furnish &

Zach MiersZach Miers Enclosure: Ben MauserEnclosure: Ben Mauser User Interface: Ben MauserUser Interface: Ben Mauser Documentation: AllDocumentation: All PCB Design: Chris Klepac & Ben MauserPCB Design: Chris Klepac & Ben Mauser

ScheduleSchedule

QuestionsQuestions

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