DEBRA:Digital Emergency Brake Response Alert SystemDEBRAProblem: Cars CrashDEBRA paradigmFunctional DiagramAccelerometer ModulePerformance InterfaceQuarter MileBraking TestToysDEBRA:DEBRA:Digital Emergency Brake Digital Emergency Brake Response Alert SystemResponse Alert SystemCharvakCharvakKarpeKarpeNathan AckermanNathan AckermanApril 23, 2004April 23, 2004DEBRADEBRAActually 2 different systemsActually 2 different systemsImproving highway safetyImproving highway safetyMeasuring car performanceMeasuring car performanceProblem: Cars CrashProblem: Cars CrashApproximately 1.5 Million rear endings Approximately 1.5 Million rear endings each yeareach yearRear ending ~23% of all accidents Rear ending ~23% of all accidents 2,000 deaths 2,000 deaths ~950,000 injuries.~950,000 injuries.Let’s make a distinction between fast Let’s make a distinction between fast braking and slow braking vehicles!braking and slow braking vehicles!DEBRA paradigmDEBRA paradigmFast braking vehicles (FBV) realize they are Fast braking vehicles (FBV) realize they are braking quicklybraking quicklyFBV sends visual and RF warning to other carsFBV sends visual and RF warning to other carsFBV flashes brake lights instead of constant on during FBV flashes brake lights instead of constant on during periods of high decelerationperiods of high decelerationFBV sends RF information to other cars notifying FBV sends RF information to other cars notifying them of decelerationthem of decelerationSurrounding cars reactSurrounding cars reactDrivers observe attention gabbing brake patternDrivers observe attention gabbing brake patternUnits in other cars listen for RF and play audio Units in other cars listen for RF and play audio warning to drivers of FBV in vicinitywarning to drivers of FBV in vicinityFunctional DiagramFunctional DiagramAccelerometer ModuleAccelerometer ModuleAcceleration = sqrt(x^2+y^2Acceleration = sqrt(x^2+y^2--1)1)Braking = [x y]*[Braking = [x y]*[xr;yrxr;yr]]Operating frequency = 20Hz to block Operating frequency = 20Hz to block vibrations.vibrations.Tests: 0Tests: 0--60mph, braking, ¼ mile, open 60mph, braking, ¼ mile, open time.time.Performance InterfacePerformance InterfaceLCD display in cockpit.LCD display in cockpit.Press 0Press 0--60 button to begin test.60 button to begin test.Timer starts automatically when Timer starts automatically when acceleration is detected.acceleration is detected.Acceleration is integrated once to get Acceleration is integrated once to get velocity.velocity.Test stops when velocity reaches 60.Test stops when velocity reaches 60.Quarter MileQuarter MilePush button to start test.Push button to start test.Acceleration is integrated twice to get Acceleration is integrated twice to get distance.distance.Timer starts when acceleration is detected Timer starts when acceleration is detected and stops when integrated distance is at and stops when integrated distance is at least ¼ mile.least ¼ mile.Braking TestBraking TestUser brings vehicle to desired start speed User brings vehicle to desired start speed (e.g. 60 mph), then presses brake test (e.g. 60 mph), then presses brake test button.button.Timer starts when braking is detected, Timer starts when braking is detected, stops when braking stops.stops when braking stops.Dual integral of acceleration provides Dual integral of acceleration provides distance output.distance
View Full Document
Unlocking...