Active Safety, 060508 cd - Chalmerswebfiles.ita.chalmers.se/~mys/ActiveSafety07/Lectures07/... ·...

PRIVATE/PROPRIETARY

Active Safety

Dr. Yngve Håland Lecture on April 26, 2007Senior Adviser, ResearchAutoliv Inc.Adjunct Professor, Vehicle SafetyChalmers University of Technology

PRIVATE/PROPRIETARY

ACEA Primary Safety Model

Phase 4In

Crash

Phase 2DangerPhase

Phase 1NormalDriving

Phase 3Crash

Unavoidable

Phase 5Post

Crash

Abnormal driving

“Active” or “Primary” Safety = Accident

Avoidance and/or Crash Severity Reduction

“Passive” or “Secondary” Safety = Injury Avoidance and/or Injury

Severity Reduction

IMPACT

“Tertiary” safety

AUTOLIV-ALR/YH/Active Safety/060508/ - 2

PRIVATE/PROPRIETARY

Accident data (EU) as basis for the developmentof Active Safety systems

• Drivers under the influence of alcohol are involvedin as much as half of all vehicle accidents with life-threatening and fatal injuries.

• Drowsy drivers and drivers with reduced performance(due to sudden sickness, drugs, use of mobile phone,computer etc.) can be involved in as many as onequarter of all accidents.


PRIVATE/PROPRIETARY

Accident data (EU) as basis for the developmentof Active Safety systems, cont.

• Half of all accidents with personal injuries occur inroad intersections and road junctions.

• Close to one third of all killed in traffic accidents arevulnerable road users (pedestrians and bicyclists).


PRIVATE / PROPRIETARY

Contributory factors*) to road accidents in the U.K.

1. Inattention 25,8%2. Failure to judge other person’s speed or path 22,6%3. Looked but did not see 19,7%4. Behaviour - careless/thoughtless/reckless 18,4%5. Failed to look 16,3%6. Lack of judgement of own path 13,7%7. Excessive speed 12,5%8. Slippery road 8,2%9. Impairment - alcohol 6,6%

10. Behaviour - in a hurry 6,5%*) “Why did this failure or manoeuvre occur?”

Source: U.K. Department for Transport, Road Statistics, 2004


PRIVATE/PROPRIETARY

NHTSA data of driver injuries vs delta V

Source: Federal Register Vol 64, No. 214 Friday November 5, 1999 / Proposed Rules

Very few severe accidents with delta v > 15 m/s(35 mph)


PRIVATE/PROPRIETARY

0

50

100

150

0 20 40 60 80 100

CollisionsSevere injuriesInjury risk

Delta velocity (km/h)

Current situationR

elat

ive

scal

e

Source: Anders Kullgren, Folksam: Results from Folksam Crash Pulse Recorder data


PRIVATE/PROPRIETARY

0

50

100

150

0 20 40 60 80 100

Collisions: 50%Severe injuries: -50%Injury risk

Reducing traffic injuries by 50% require collision reduction by 50% all other equal


Rel

ativ

e sc

ale

Source: Anders Kullgren, Folksam: results from Folksam Crash Pulse Recorder data


PRIVATE/PROPRIETARY

0

50

100

150

0 20 40 60 80 100

Collisions: dV -10 km/hSevere injuries: -50%Injury risk


Reducing traffic injuries by 50% also through 10 km/h velocity reduction

Rel

ativ

e sc

ale

Source: Anders Kullgren, Folksam: results from Folksam Crash Pulse Recorder data


PRIVATE/PROPRIETARY

Active Safety - Passive Safety

Passive Safety

RescueOccupant ProtectionCrash Likelihood

Driver Support

Normal DrivingCrash Avoidance / Mitigation

Pre-Crash Phase

Assisting & WarningSystems

• Blind spot detection

• Lane change aid• Backing aid• Adaptive cruise

control• Road sign

assistant

Pre-CrashSystems

In-CrashSystems

• Brake assistant • Reversible belts• Night vision• Road departure

warning• Collision warning • Drowsiness

warning

• Stability control• Emergency braking • Occupant classification• Rollover detection • Pre-crash sensing• Pedestrian detection• Automatic braking

• Adaptive belts• Adaptive bags• Dual pretensioning• Leg protection• Anti-whiplash• Child restraints• Pedestrian

protection

Crash

Post-crashSystems

• Battery cut-off • Crash recorders• Emergency

call system

Active Safety


PRIVATE/PROPRIETARY

Pre-crash sensing


PRIVATE/PROPRIETARY

Safety Phase Chart

Mitig.long term

Mitig. short term

Protect

comfort Individual external conditions

Sensing Acting Rescue/care Reconstruction

Active Safety Passive Safety

Crash is avoidable

Driver is in control

Driver is fit

Car is fit Prepare for the crash

Car dynamics

driver aid autom. vehicle control in emergency conditions

Pre-Crash In-Crash and Pedestrian crashes

Post-Crash

Contact

+¤Point of no

return

-100ms-300ms

Collision AvoidanceCA

Post Crash“Golden Hour”

Incrash

200ms

Precrash


PRIVATE/PROPRIETARY

Market SituationAvailable Systems

ESC: all OEMsConti, Bosch, TRW, Mando, Denso etc

ACC: most high end carsConti, Bosch, TRW, Delphi, Omron, Denso

LDW: PSA, NissanValeo

TPM: All OEMsValeo, Schrader, Beru, Pacific

NV: Honda, Toyota, (BMW)L3, Denso, Autoliv

PreSafe, PreCrash: DC, Toyota, NissanConti, Denso, Omron

Automatic Parking: ToyotaDenso


PRIVATE/PROPRIETARY

ACC

>100 mSensor Requirements- >1 sec. think time- Long range of operation-Accurate range- Narrow Field of view OKSensing options- Radar, Laser Radar- Mono Vision

50 mSensor Requirements- 250 ms think time- Limited Classification- Accurate range- Wider field-of-viewSensing options- Vision: mono or stereo- Vision + Radar

10 mSensor Requirements- < 50 ms think time- Accurate Classification- Accurate range- Wide field-of-view criticalSensing options- Stereo-vision- Stereo-Vision + Radar

Urban ACCStop-n-goCollisionDetection

Forward Looking SensorsRequirements


PRIVATE/PROPRIETARY

Forward Looking SensorsTechnologies

24 GHz Radar(79 GHz Radar)

Radar error

SVSStereo Vision

Vision error

Combination error

Sensor Data Fusion


PRIVATE/PROPRIETARY

Autoliv 24 GHz radar sensing system

Sensing subsystem• Cover the front of the vehicle up to 10-15m• Two standalone radar sensors with pencil beams

• Packaged inside the bumper beam behind the plastic fascia• Dimensions 100mm*65mm*70mm


PRIVATE/PROPRIETARY

Autoliv Integrated Safety Approach

To develop and propose new safety solutionswith sensing systems common for

1) enhanced and new passive safetysystems

2) active safety systems to avoid crashesor to mitigate crash severities


PRIVATE/PROPRIETARY

Possible benefits of pre-crash

triggered airbags


PRIVATE/PROPRIETARY

Normal bag and benign bag in OOP test


PRIVATE/PROPRIETARY

Preliminary test results OOP6-year HIII in "head on instrument panel" OOP

0

0,5

1

1,5

2

2,5

3

Normal Benign

6-year HIII

Leve

l rel

ativ

e IA

RV HIC15[700N]

Fcomp.[1820/4000N]

Ftension[1490/4170N]

Nij[1]

Deflection[40/63mm]

VC[1]

Chest acc[60g]


PRIVATE/PROPRIETARY

r

Radar sensors

Stereo Vision Sensor

Pre-impact TriggeringDouble sensors to avoid false activations

Sensor information based on two different physical signals

Note. If pre-crash sensors fail to trigger, conventional in-crash sensors will trigger (back-up).


PRIVATE/PROPRIETARY

Airbag models

Standard driver bag Large driver bag (diameter scaled by 1.2)

56 km/h full frontal test w. belted driver


PRIVATE/PROPRIETARY

ResultsChest acc. vs. time

050

100150200250300350400450

0 0,02 0,04 0,06 0,08 0,1

Time (s)

Acc

eler

atio

n (m

/s^2

)Standard driver bagLarge driver bag

Chest acc. vs. displacement

050

100150200250300350400450

0 0,05 0,1 0,15 0,2 0,25 0,3

Displacement (m)

Acc

eler

atio

n (m

/s^2

)

Standard driver bagLarge driver bag


PRIVATE/PROPRIETARY

0102030405060708090

100

0 10 20 30 40 50 60 70 80

Cum

m. (

%)

w/o brakingw. braking of both cars

Decrease of risk of AIS 3+ injuries for belteddriver in frontal car-to-car collision due to

automatic pre-crash braking (0,5g)*)

*) Triggered by near-zone radar (e.g. 24 GHz) at 11 m distance. (Note. 0,5g braking200 ms after triggering possible in car with ESP without any modifications.)

Delta-v (km/h)

-8%

-24%

-57%


PRIVATE/PROPRIETARY

Function of VES *)

100m 200m 300m 400m 500m 600m 700m

Look-ahead distance (experienced driver)

100m 200m 300m 400m 500m 600m 700m

70-100 m

Night Vision range (ideal conditions)

Dippedheadlight

range Response time (90 km/h): ~40 m Braking distance: ~50 m

*) VES = Visual Enhancement SystemAUTOLIV-ALR/YH/Active Safety/060508/ - 25

PRIVATE/PROPRIETARYAUTOLIV-ALR/YH/Active Safety/060508/ - 26

BMW Night Vision

Source: BMW AG

PRIVATE/PROPRIETARY

Night Time Driving

• Night time driving overall 2-3 times more dangerousthan day time. 3 main factors 1:

- Increased alcohol involvement- Increased fatigue/sleepiness/cardiac rhythm- Decreased visibility

• Autoliv started working on the 3rd item above• Pedestrians and animals accidents are especially

over represented at night time

1 M. Sivak: Most promising way of improving night time traffic, Vehicle & Infrastructure Safety Improvements in Adverse Conditions and Adverse Weather, SIA Rouen 24-25 September 2002


PRIVATE/PROPRIETARY

Driver’s view withapproaching vehicle

on low beam

Driver’s view withapproaching vehicle

on high beam

Long Wave IR:Insensitive to Glare From Oncoming Traffic


PRIVATE/PROPRIETARY

Honda Night Vision using FIR

• “Honda Develops World’s First Intelligent Night Vision System Able to Detect Pedestrians and Provide Driver Cautions—Available on Legend model to be released in Fall 2004”http://world.honda.com/news/2004/4040824_01.html


PRIVATE/PROPRIETARY

Pedestrian Detection


PRIVATE/PROPRIETARY

Pedestrian Injury Mitigation System

Phase 4In

Crash

Phase 2DangerPhase

Phase 1NormalDriving

Phase 3Crash

Unavoidable

Phase 5Post

Crash

Abnormal driving

“Active” or “Primary” Safety = Accident

Avoidance and/or Crash Severity Reduction

“Passive” or “Secondary” Safety = Injury Avoidance and/or Injury

Severity Reduction

IMPACT

“Tertiary” safety

Project Focus: Reduce impact speed in Pedestrian Accidents


PRIVATE/PROPRIETARY

1

0

10

20

30

40

50

60

70

80

90

100

0 10 20 30 40 50 60 70 80 90 100 110 120 130

Kollisionshastighet i km/h

Ris

k at

t död

as i

% Gående eller cyklist Sidokrock Frontalkrock eller plötsligt stopp mot hårt föremål

Fatality risk vs impact speedfor different types of collisions

~75%

~8%

~28%

Average impact velocity in a pedestrian accidentcausing severe injuries or fatalities

Pedestrian impacts

Side Impact Frontal Impact

Source: Gunnar Karlsson NTF. Based on “Svenska kommunförbundets” document “Lugna Gatan”.


PRIVATE/PROPRIETARY

Pre-Impact Braking in Pedestrian Collisions

• Braking force 0.6 g from a distance of 10 m to the pedestrian

ØCollision speed reduced from 40 to 9 km/h=> fatality risk reduced from ~28% to about zeroØCollision speed reduced from 50 to 31 km/h

=> fatality risk reduced from ~75% to about 10%

Note: Time/distance for detection and applying the brakes must be added.


PRIVATE/PROPRIETARY

Pedestrian Impact Mitigation Systemwith pre-impact sensing

10 m0 m

Infrared SensingModule

Pedestrian recognition

• Low Cost, Far Infrared sensor suitable for Pedestrian Detection and other Vulnerable Road Users.

• PIMS System:• Custom designed IR imaging module for sensing• Improving Brake Assist functionality by automatic activation after the driver

has failed to react


PRIVATE/PROPRIETARY

Pedestrian Detection

Driver Assistance (driver in the loop):50 m distance.

PIMS*) (automatic activation):About 10 m distance.

*) Pedestrian Injury Mitigation System


PRIVATE/PROPRIETARY

In-depth study of frontal, oblique andside collisions between vehicles in

road intersections using GIDAS1) data

1) German In-Depth Accident Study


PRIVATE/PROPRIETARY

Type 2: Turning accident AB201 202 203

cyclist from bicyclelane

204

lane change forturning off

209unspecified if 201- 204

20left turning veh –following veh

101 2,4% 52 1,2%

1533,6%

211 212 213 214 215 219driving directionnot specified

21left turning veh –oncoming traffic inlane

322 7,6% 2 0,0% 2 0,0% 2 0,0%

3287,7%

221 222 223 224 225 229unspecified if 221– 225

22left turning veh –pedestrian / vehiclefrom special lane

9 0,2% 15 0,4% 15 0,4% 25 0,6% 4 0,1%

681,6%

231 232 233

lane change forturning off

239unspecified if 231– 233

23right turning veh –following veh

31 0,7% 12 0,3% 6 0,1%

491,2%

24right turning veh –pedestrian / vehiclefrom special lane

241 242 243 244 245 249unspecified if 241– 245 59

1,4%


PRIVATE/PROPRIETARY

Type 211 - Vehicle A turns left into the pathof oncoming vehicle B, where vehicle B

has the right of way The minimum distance between collision partners when vehicle A is at the point of no escape.

Minimum distancebetween vehicleswhen vehicle A atPONE (m)

A_b,B_b

A_nb,B_b

A_b,B_nb

A_nb,B_nb

Allcases

% allcases

0-5 1 13 2 19 35 31.86-10 2 9 3 9 23 20.9

11-15 3 5 3 12 23 20.916-20 3 6 3 7 19 17.321-25 2 2 1.826-30 1 1 2 1.831-35 1 1 0.936-40 1 2 3 2.741-45 1 1 2 1.8Total 9 36 12 53 110 100.0

b = braked, nb = not braked


PRIVATE/PROPRIETARY

Type 211 - Vehicle A turns left into the pathof oncoming vehicle B, where vehicle B

has the right of way - cont.

b = braked, nb = not braked

The closing velocity at the point of no escape.

Closing velocity whenvehicle A at the pointof no return (kph)

A_b,B_b

A_nb,B_b

A_b,B_nb

A_nb,B_nb

Allcases

% allcases

0-15 1 1 0.916-30 0 0.031-45 4 3 7 6.446-60 1 5 4 17 27 24.561-75 5 5 5 15 30 27.376-90 2 11 2 6 21 19.191-105 1 6 6 13 11.8

106-120 2 6 8 7.3121-135 3 3 2.7

Total 9 36 12 53 110 100.0


PRIVATE/PROPRIETARY

Consequences of pre-crash braking

• If vehicle B with a speed of 70 km/h starts to brakewith 0,6 g at a distance of 10 m from vehicle A, theclosing velocity will be reduced to 58 km/h at the timeof impact.

• The fatality risk for a near side occupant in vehicle Awill be reduced from about 60% to 25%.


PRIVATE/PROPRIETARY

Definition of Integrated Safety

To avoid accidents, mitigate collision/accident severities and minimize injuries by using common sensing information.

Transition from the area Pre-Crash into the area IntegratedSafety starts just before the time a collision or an accident is inevitable, and the driver no longer is in control.

PRIVATE/PROPRIETARY

State of the artGlobal view

The first step into integration of passive and active safety wastaken by Mercedes-Benz in 2002 with the PRE-SAFE system. (By use of reversible seat belt pretensioners activated before a possible accident, the driver and the passenger can be firmly pressed into their seats and thereby be better coupled to the vehicle. Critical driving conditions are identified by the vehicle’s ESP and the BAS systems.)

PRIVATE/PROPRIETARY

State of the artGlobal view cont.

The next generation of the PRE-SAFE system was taken by Mercedes-Benz in the new S-Class model in 2005. (The system now also includes a long-distance radar (77 GHz) and also a short range radar (24 GHz)).

Considerable potential for reducing the loads to the car occupants, due to activation of the PRE-SAFE, has been reported by Mercedes-Benz.Similar systems have now also been introduced by Toyota, Honda and Nissan.

PRIVATE/PROPRIETARY

State of the artTrends

Only reversible active and passive safety systems can be activated pre-crash. (Note. The risk of false activations can not be eliminated.)

A false activation must be perceived as an acceptable event (by the driver and other vehicle occupants). There must be considerable reductions in injury risks to justifyadditional costs. (The cost of sensing systems and actuators must be reduced.)

Active Safety, 060508 cd - Chalmerswebfiles.ita.chalmers.se/~mys/ActiveSafety07/Lectures07/... ·...

Documents

Transcript of Active Safety, 060508 cd - Chalmerswebfiles.ita.chalmers.se/~mys/ActiveSafety07/Lectures07/... ·...