CICAS Coordination Meeting

September 28th, September 28th, 20042004

Virginia Update

Research Questions Research Questions Addressed To DateAddressed To Date Is there a difference in brake profiles for Is there a difference in brake profiles for

distracted vs. willful vs. baseline drivers?distracted vs. willful vs. baseline drivers? What’s a too early warning?What’s a too early warning? What’s a too late warning?What’s a too late warning? What timing aspects of the algorithm will What timing aspects of the algorithm will

minimize false alarms and misses? minimize false alarms and misses? What is the effect of warning mode on driver What is the effect of warning mode on driver

response?response? How many detection points are needed to How many detection points are needed to

have an effective algorithm?have an effective algorithm? What functional requirements are known?What functional requirements are known?

Is there a difference in brake Is there a difference in brake profiles for distracted vs. profiles for distracted vs. willful vs. baseline drivers?willful vs. baseline drivers?

0 50 100 150 200 2505

10

15

20

25

30

35

40

Distance from Intersection (ft)

Speed o

f V

ehic

le (

mi/hr)

DistractedWillfulBaseline

Braking ProfilesBraking Profiles

Algorithms can be built based on Algorithms can be built based on detection of violation-likely groups:detection of violation-likely groups:– Drivers stop differently depending on their Drivers stop differently depending on their

intentions and level of distractionintentions and level of distraction Distracted drivers stop harder than othersDistracted drivers stop harder than others Distracted drivers are less likely to stopDistracted drivers are less likely to stop Distracted drivers are more likely to violateDistracted drivers are more likely to violate Willful drivers tend to speedWillful drivers tend to speed

What’s a too early What’s a too early warning?warning? A warning that is issued to a A warning that is issued to a

driver that would have stopped driver that would have stopped without any interventionwithout any intervention– Creates annoyanceCreates annoyance– Decreases user trustDecreases user trust

Too early was determined during Too early was determined during first three intersection studiesfirst three intersection studies

Too Early DistributionToo Early Distribution

• The figure depicts the distance from the intersection at which baseline drivers initiated braking when the signal change occurs at 185’

• An algorithm that initiates a warning prior to reaching 135’ would create false alarms

Nu

mb

er

of

Dri

ve

rs (

ou

t o

f 2

8)

Distance to Intersection (ft)

What’s a too late What’s a too late warning?warning? A warning that is issued to a A warning that is issued to a

driver that would benefit, but with driver that would benefit, but with timing such that insufficient timing such that insufficient distance remains for the driver to distance remains for the driver to perceive, react, and stop prior to perceive, react, and stop prior to entering the intersection.entering the intersection.– Decreases safety benefit of systemDecreases safety benefit of system– Decreases user trustDecreases user trust

Inneffective Warning Timing (Too Late)

Pro

babili

ty

Warning Region

0 ft 250 ft

Annoyance Warning (Too Early)

Pro

babi

lity

Inneffective Warning Timing (Too Late)

Pro

babili

ty

Warning Region

0 ft 250 ft

Annoyance Warning (Too Early)

Pro

babi

lity

Ideal Case – Classification Ideal Case – Classification ClearanceClearance

Real Case – Classification InterferenceReal Case – Classification Interference

Annoyance Alarm (Too Early)

Nor

mal

Pro

babi

lity

Warning Region

0 ft 250 ft

Ineffective Warning Timing (Too Late)

Pro

babili

ty

Maximizing Curve SeparationMaximizing Curve Separation(Methods to Minimize Misses and False (Methods to Minimize Misses and False Alarms)Alarms)

Take advantage of the “all red” phase Take advantage of the “all red” phase and the time it takes for opposing and the time it takes for opposing vehicles to get into the collision zone to vehicles to get into the collision zone to allow vehicles to pass through without allow vehicles to pass through without warning (time)warning (time)

Take advantage of the intersection’s Take advantage of the intersection’s buffer zone, the area beyond the stop buffer zone, the area beyond the stop bar but prior to significant collision risk bar but prior to significant collision risk (space)(space)

Design warnings that minimize reaction Design warnings that minimize reaction time and maximize deceleration by time and maximize deceleration by conveying necessary urgencyconveying necessary urgency

“Normal” Brake Initiation

Normal ApproachNormal ApproachNo Warning or Timely WarningNo Warning or Timely Warning

Too Late WarningToo Late Warning

Algorithm Trip

Reaction Time“Normal” Brake Initiation

Allowing the ViolationAllowing the ViolationPreventing the CrashPreventing the Crash

Making Use of Pre-Collision Zones Making Use of Pre-Collision Zones of the Intersectionof the Intersection

Compliant

Zone

Violation Zone

Intrusion Zone

Collision Zone

Warning Activation

Preventing the CollisionPreventing the Collision

Maximize Warning Maximize Warning EffectivenessEffectiveness

DII/DVI research to date has DII/DVI research to date has demonstrated the importance of demonstrated the importance of countermeasure design.countermeasure design.– Prototype warnings were evaluated for Prototype warnings were evaluated for

Urgency, Distinguishability, and Urgency, Distinguishability, and Appropriateness in the labAppropriateness in the lab

Evaluators preferred icon auditory warnings Evaluators preferred icon auditory warnings over descriptive (i.e. buzzer vs. “Stop”)over descriptive (i.e. buzzer vs. “Stop”)

However, experimentation showed However, experimentation showed clear advantages for the word “Stop”clear advantages for the word “Stop”

Maximize Warning Maximize Warning EffectivenessEffectiveness

0

10

20

30

40

50

60

0 50 100 150 200 250

Distance from Intersection (ft)

Sp

eed

(ft

/sec

)

"Stop" CAMP Warning

Comparison of Comparison of Auditory Alerts Auditory Alerts

GroupPercent Who Stop Before

Collision Zone

Avg. Maximum Deceleration (g)

Avg. Reaction Time (sec)

CAMP Warning

64% -0.64 0.88

“Stop” 81% -0.73 1.07

Effectiveness of Visual Effectiveness of Visual DisplayDisplay

– High Heads-Down Visual DVI was High Heads-Down Visual DVI was ineffectiveineffective The display was perceived by less than The display was perceived by less than

5 percent of the participants5 percent of the participants Evaluation of DVIs is now focused on Evaluation of DVIs is now focused on

auditory and haptic warning modesauditory and haptic warning modes

How many detection points How many detection points are needed to have an are needed to have an effective algorithm?effective algorithm? Single-Point detection of speed does not Single-Point detection of speed does not

result in reliable warning decisionsresult in reliable warning decisions– Improved reliability would consistently result Improved reliability would consistently result

in too late warningsin too late warnings

Continuous detection is the most Continuous detection is the most adaptive to any algorithm type and adaptive to any algorithm type and produces the best theoretical produces the best theoretical performanceperformance

Multi-point alternatives are being testedMulti-point alternatives are being tested

Simulation of Single Simulation of Single Point vs. Continuous Point vs. Continuous DetectionDetectionMissed ViolationsMissed Violations

0 50 100 150 200 250 300 3500

10

20

30

40

50

60

70

Range (feet)

Spe

ed (

mph

)

0 50 100 150 200 250 300 3500

10

20

30

40

50

60

70

Range (feet)

Spe

ed (

mph

)

Speed determined at given distance from intersection Speed determined at given distance from intersection for violations that occurredfor violations that occurred

Single point detection would not have worked for most Single point detection would not have worked for most of the drivers who violatedof the drivers who violated

With continuous detection, three violating drivers With continuous detection, three violating drivers would not have been detected; however, none of would not have been detected; however, none of these drivers would have been in the crash zone.these drivers would have been in the crash zone.

What functional requirements What functional requirements are known?are known?

Detuning tests run to dateDetuning tests run to date– SensorsSensors

AccelerationAcceleration VelocityVelocity

– PositioningPositioning Lateral PositionLateral Position Longitudinal PositionLongitudinal Position

0.00.10.20.30.40.50.60.70.80.91.0

Velocity Detuning Level

No

rma

lize

d M

ea

n

Re

qu

ire

d D

ec

ele

rati

on

(g

)

Sensor: VelocitySensor: VelocityNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

Sensor: VelocitySensor: VelocityNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

0.00.10.20.30.40.50.60.70.80.91.0

Velocity Detuning Level

No

rma

lize

d M

ea

n

Re

qu

ire

d D

ec

ele

rati

on

(g

)

25mph

70mph

Sensor: AccelerometerSensor: AccelerometerNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-0.05g -0.025g 0.0g 0.025g 0.05g

Acceleration Detuning Level

No

rmalized

Mean

Req

uir

ed

Decele

rati

on

(g

)

Positioning: LateralPositioning: LateralNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-5 m -2.5 m -1 m 0 m 1 m 2.5 m 5 m

Lateral Positioning Detuning Level

No

rmalized

Mean

Req

uir

ed

Decele

rati

on

(g

)

25mph

70mph

D = 125 ft

d = 125.6 ft

Positioning: LateralPositioning: Lateral

Assumes a 12 foot lane widthAssumes a 12 foot lane width Would also apply to curved road Would also apply to curved road

geometrygeometry

Positioning: LateralPositioning: LateralLane Position: Correct vs. IncorrectLane Position: Correct vs. Incorrect

 25 mph Correct

25 mph Incorrect

70 mph Correct

70 mph Incorrect

-5 m 0 6 0 6

-2.5 m 0 6 3 3

-1 m 6 0 6 0

0 m 6 0 6 0

1 m 6 0 6 0

2.5 m 0 6 1 5

5 m 0 6 0 6

Positioning: LongitudinalPositioning: LongitudinalNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

0.0

0.4

0.8

1.2

1.6

2.0

-15 m -10 m -5 m -3.5 m -2 m -1 m 0 m 1 m 2 m 3.5 m 5 m 10 m 15 m

Longitudinal Positioning Detuning Level

No

rmal

ized

Mea

n

Req

uir

ed D

ecel

erat

ion

(g)

25 mph

70 mph

Positioning: LongitudinalPositioning: LongitudinalNormalized Deceleration: At DVI onset, the Normalized Deceleration: At DVI onset, the average deceleration in g’s that would be required average deceleration in g’s that would be required to stop by the stop barto stop by the stop bar

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

-5 m -3.5 m -2 m -1 m 0 m 1 m 2 m 3.5 m 5 m

Longitudinal Position Detuning Error

No

rma

lize

d M

ea

n

Re

qu

ire

d D

ec

ele

rati

on

(g

)

25 mph

70 mph

Project PlansProject Plans

Completing studies to answer the following Completing studies to answer the following questionsquestions– What is the optimal timing for collision warning?What is the optimal timing for collision warning?– What is the optimized braking profile for a haptic What is the optimized braking profile for a haptic

warning system?warning system?– What are the remaining functional requirements What are the remaining functional requirements

and specifications of an ICA system?and specifications of an ICA system?– What DII and DVI will result in optimal driver What DII and DVI will result in optimal driver

response?response?– What technologies show the most promise for the What technologies show the most promise for the

feasible architectures?feasible architectures?– What ICA architectures are feasible for meeting the What ICA architectures are feasible for meeting the

requirements and specifications?requirements and specifications?

What is the optimal What is the optimal timing for collision timing for collision warning?warning? Need to continue to systematically Need to continue to systematically

determine the ‘too late’ points for determine the ‘too late’ points for various DIIs and DVIsvarious DIIs and DVIs– A goal of zero misses is being usedA goal of zero misses is being used– Driver acceptance is being consideredDriver acceptance is being considered

‘‘Too late’ thresholds are being Too late’ thresholds are being contrasted with known ‘too early’ contrasted with known ‘too early’ thresholds, to determine the potential thresholds, to determine the potential for nuisance alarmsfor nuisance alarms

What is the optimized What is the optimized braking profile for a haptic braking profile for a haptic warning system?warning system?

It is known that severely distracted drivers It is known that severely distracted drivers can have perception reaction times as long can have perception reaction times as long as 4 sec, which would make any traditional as 4 sec, which would make any traditional warning ineffectivewarning ineffective

A brake assist or full brake system is seen as A brake assist or full brake system is seen as a possible means of aiding these drivers, a possible means of aiding these drivers, since reaction time is eliminatedsince reaction time is eliminated

Three issues are being resolved:Three issues are being resolved:– When should the system be activated?When should the system be activated?– How long should the system remain active?How long should the system remain active?– How much braking authority should be used?How much braking authority should be used?

Brake Assist ExampleBrake Assist Example

Braking Profiles, 35 mph Example

0.0

0.2

0.4

0.6

0.8

0 1 2 3 4 5 6

Time from Warning Initiation, secs

Dec

eler

atio

n,

g's

Driver braking at 0.4 g from 1.5 s

Assisted Braking, Ease-On at 1 s, rise to 0.65 g after 0.5 s

Savings of 50ft at Savings of 50ft at 35mph35mph

Effect of Assisted Braking

0

100

200

300

400

500

0 10 20 30 40 50 60

Initial Vehicle Speed, mph

To

tal

Sto

pp

ing

Dis

tan

ce

, ft

Typical Brake to Warning: RT=1.5 s, decel=0.4 g

Assisted Braking Case: On at 1.0 s, decel rises to 0.7 g in 0.5 s

What are the remaining What are the remaining functional requirements and functional requirements and specifications of an ICA specifications of an ICA system?system? Need to test between 1 m and 2.5 Need to test between 1 m and 2.5

m on lateral position.m on lateral position. Need to determine effects of Need to determine effects of

various communication system various communication system update ratesupdate rates

What DII and DVI will What DII and DVI will result in optimal driver result in optimal driver response?response? Will continue to conduct Will continue to conduct

evaluation of brake assist and full evaluation of brake assist and full brake options.brake options.

Will continue to test auditory and Will continue to test auditory and haptic options.haptic options.

What technologies show the What technologies show the most promise for the feasible most promise for the feasible architectures?architectures?

VTTI will continue to determine VTTI will continue to determine technologies that meet the minimal technologies that meet the minimal functional requirementsfunctional requirements– ControllerController– PositioningPositioning– SensorsSensors– Driver InterfaceDriver Interface– CommunicationsCommunications– Computations Computations

Controller Controller TechnologiesTechnologies No single interface standard availableNo single interface standard available Available timing information not accurate Available timing information not accurate

enoughenough– Ex.: Eagle controllers report timings to whole Ex.: Eagle controllers report timings to whole

secondsseconds Overhead from 10Hz polling may overload Overhead from 10Hz polling may overload

controllercontroller May need to mandate standards for data May need to mandate standards for data

format/availabilityformat/availability New Advanced Traffic Controllers (ATCs) may New Advanced Traffic Controllers (ATCs) may

address some of these issuesaddress some of these issues

Positioning Positioning TechnologiesTechnologies Infrastructure basedInfrastructure based

– Radar: costly to cover all lanesRadar: costly to cover all lanes– RFID: may require multiple readers per RFID: may require multiple readers per

approachapproach Vehicle basedVehicle based

– GPS with INS: high cost to get high GPS with INS: high cost to get high accuracy and update rateaccuracy and update rate

– RFID in conjunction with odometer: high RFID in conjunction with odometer: high accuracy at one distance, then decrement accuracy at one distance, then decrement remaining distance using odometerremaining distance using odometer

Sensor TechnologiesSensor Technologies

InfrastructureInfrastructure– Radar: velocity and decelerationRadar: velocity and deceleration

Vehicle velocityVehicle velocity– GPS with INS: velocityGPS with INS: velocity– Velocity from vehicle networkVelocity from vehicle network

Vehicle decelerationVehicle deceleration– Accelerometer to sense brakingAccelerometer to sense braking– Mechanical sensor on brake pedalMechanical sensor on brake pedal

Driver Interface Driver Interface TechnologiesTechnologies

InfrastructureInfrastructure– StrobesStrobes– VMS signVMS sign– Intelligent rumble stripsIntelligent rumble strips

VehicleVehicle– Auditory: tones or voice warningAuditory: tones or voice warning– Haptic: Soft braking (pulses), seat Haptic: Soft braking (pulses), seat

shaker, brake assist, or full brakingshaker, brake assist, or full braking

Communications Communications TechnologiesTechnologies Must be generic to support multiple Must be generic to support multiple

interfacesinterfaces Bi-directional link depending on Bi-directional link depending on

architecturearchitecture DSRC current best choiceDSRC current best choice

– Not yet available off-the-shelfNot yet available off-the-shelf– Security issuesSecurity issues– Styling issuesStyling issues– Currently simulating with 802.11a hardware Currently simulating with 802.11a hardware

and softwareand software

Computations Computations TechnologiesTechnologies

InfrastructureInfrastructure– On board signal controllerOn board signal controller– Custom DSP or hybrid microcontrollerCustom DSP or hybrid microcontroller

Must talk to infrastructure components Must talk to infrastructure components – radarradar– RFID RFID – DSRC DSRC – DIIDII

Easily modified to allow algorithm Easily modified to allow algorithm changeschanges

Computations Computations TechnologiesTechnologies VehicleVehicle

– Custom DSP or hybrid microcontrollerCustom DSP or hybrid microcontroller Must talk to all necessary data sourcesMust talk to all necessary data sources

– vehicle networkvehicle network– DSRCDSRC– GPS w/INSGPS w/INS– RFIDRFID– DVIDVI

Easily modified to allow algorithm changesEasily modified to allow algorithm changes

What ICA architectures are What ICA architectures are feasible for meeting the feasible for meeting the requirements and requirements and specifications?specifications? VTTI will continue to evaluate the VTTI will continue to evaluate the

available technologies as suitable to available technologies as suitable to several architecturesseveral architectures– Infrastructure onlyInfrastructure only– Mostly infrastructure based with receiver Mostly infrastructure based with receiver

and DVI in vehicleand DVI in vehicle– Mostly vehicle based with transmitter in Mostly vehicle based with transmitter in

infrastructure (provides stop bar location infrastructure (provides stop bar location and signal phase/timing)and signal phase/timing)

– Totally vehicle based with map in vehicleTotally vehicle based with map in vehicle For stop signed intersectionsFor stop signed intersections

Architecture Example 1. RFID tag reader and in-vehicle warning

RFID transmits distance to

intersection to vehicle

Odometer updates distance

to intersection

DVI in vehicle presents warning and driver stops

DSRC transmits signal phase and timing to vehicle

Radar determines vehicle speed and

distance

Architecture Example 2. Infrastructure radar and DII

Radar determines vehicle speed and

distance

Algorithm calculates violation

DII in infrastructure

presents warning and driver stops

DSRC violation warning also transmitted to properly

equipped vehicles

Architecture Example 3. In-vehicle positioning system and in-vehicle warning

In-vehicle map query for stop bar

location

Distance and speed calculated

to check for violation

DVI in vehicle presents warning and driver stops

STOP

STOP STOP

STOP

Additional Pre-FOT Additional Pre-FOT TestingTesting Next steps toward an FOTNext steps toward an FOT

– Passive evaluation of both Passive evaluation of both infrastructure based and cooperative infrastructure based and cooperative ICA systemsICA systems When was the warning issued?When was the warning issued? How many false alarms and misses How many false alarms and misses

occurred?occurred? What would have been the resulting What would have been the resulting

driver and traffic consequences?driver and traffic consequences?

Additional Pre-FOT Additional Pre-FOT TestingTesting Data from the passive evaluation will Data from the passive evaluation will

also validate the functional also validate the functional specifications for a cooperative systemspecifications for a cooperative system

Then we will have enough data to Then we will have enough data to activate the DII warning at a limited activate the DII warning at a limited number of intersections and continue number of intersections and continue to closely monitor trafficto closely monitor traffic– Do naturalistic on-road experimentation Do naturalistic on-road experimentation

for the cooperative system with for the cooperative system with instrumented vehicleinstrumented vehicle

Look for unintended consequencesLook for unintended consequences Make the final assessment of acceptabilityMake the final assessment of acceptability