Active suspension

Introduction to Active suspension, advantages, disadvantages, different vehicles using active suspension

1. Active suspension
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Automotive Mechatronics
2161AU118
Under-Dr.V. Harish
By-Intakhab khan
VTP2984

2. Table of content
1.Introduction
2.Types of suspension and difference
3.Active suspension
•Introduction
•Components
•Working
•Vehicle performance
•Advantages
•Disadvantages
•Present vehicles using Active suspension
4.Other advancement
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3. Introduction
•Suspensionsystemisthesystemconsistingsprings,shockabsorbersand
havinglinkageswhichisusedtoisolatesprungmassfromtheroadshocks,
vibrationsandprovidestability.Theyconsistofspringanddamperspring
takesthevibrationsanddampersreducestheeamplitudeofvibrationand
dampthevibration.
•Mainfunctionsofsuspensionsystemare
•Toisolatebodyfromroadshocks
•Tosupporttheweightofthevehicle
•Toprovidesmoothride
•Allowsrapidcorneringwithoutextremebodyroll
•Ithelpstomaintainthecontactbetweenroadandtyre.
•Preventsquatduringaccelerationanddiveduringbraking
•Givesparticularheighttovehiclebody
•Maintainspropersteeringgeometry
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4. Types of suspension
Automotive suspension
Passive
suspension
Semi-Active
suspension
Active
suspension
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Passive suspension: The old conventional suspension system are passive type in which damping and spring
rate are not changes as per real time working condition.
Semi –Active type suspension system: With the road conditions the damping coefficient is varied and give
comfortable rides for example MR fluid
Active Suspension system: Constantly road surface conditions are sensed that are fed into ECU which adjusts
the shock stiffnessandspring rate improving ride performance, drivability, responsiveness, etc.

5. Difference between passive, semi active and active suspension
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6. Active Suspension
•Itisarealtimeadaptivesuspensionworkingonreal
timeroadconditionandvaryingthedampingratesas
wellasspringrate(changingthetravel)aspertheneed
tooffercomfortableride.
•Theyuseactuatortoraiseorlowerthechassisateach
wheelaspertimesensorreadingofroadcondition
•Actuatorsarecontrolledbytheonboardcomputers
gettingtheinputfromsensors
•It"artificially"extendsthedesignparametersofthe
systembyconstantlymonitoringandadjustingitself,
therebychangingitscharacteronanongoingbasis.
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7. Components of Active Suspension
•ECU(Electroniccontrolunit)and
ESC(Electronicstabilitycontrol)
•Stereocamera
•Pump
•Reservoir
•Sensors(Levelsensors,speedsensor,
Inertialsensor,3axisacceleration
sensor, pressure sensors,
displacementsensors,steering
positionsensor)
•Actuatorsforeachsuspension(Shock
absorberswithelectricallyvariable
resistanceand/orstrutsthatcanbe
extendedorretractedbasedon
electricsignalinput.)canbehydraulic
orelectromagnetic
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8. Block diagram
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9. Working of active suspension
•Activesuspensionworksbyconstantlysensingchangesintheroadsurfaceand
feedingthatinformation,viatheECU,totheoutlyingcomponents.These
componentsthenactuponthesystemtomodifyitscharacter,adjustingshock
stiffness,springrateandthelike,toimproverideperformance,drivability,
responsiveness,etc.
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•Whiletakingaturnthevehiclesensesitby
steeringsensor,speedofwheelsandinertial
sensorssensesyawandrollandthesesignals
aresenttoECUthentheECUsendsthesignal
totherightservopresentatthetopofwheels
andincreasesthestiffnessbyprovidingmore
amountofpressurizedoiltoincreasethespring
rateandstiffenthesuspensionintheouter
sidetopreventroll.

10. Working of active suspension
•Whileacceleratingordeceleratingtheinertial
sensorsensesitthroughacceleratorpedalinput
andwheelspeedsensorandmanagesthe
stiffnessoftherearorfrontwheeltoprevent
pitching.Thefeedbackistakenfrominertial
sensors.
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•Whilecruisingthevehicleheightisdecreasedto
increasethestabilitybydecreasingthecentreof
gravity.
•Togivethedrivercomfortthereistheheight
riseinAudiA8
•Whenthestereocamerareadsanypotholethe
wheelsandtherespectivewheelsareenergized
toincreasedampingcoefficient.

11. Working of active suspension
•Incaseofsidecollisionheightisincreasedtogettheimpact
ontheportionwithhighlyreinforcedpartofvehicle.
•Whileridingoff-roadasthedriversneedstheheight
increasethedrivercandofromtheinstrumentalpanelasin
GMCHummerEV2022.Levelsensorsgetsthefeedbackand
correctlymaintainstheheight.(149mm)
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Thethreeaccelerationsensornamelyvertical,lateralandlongitudinalsenses
heightrise,sidemovementsandaccelerationaswellasdecelerationrespectively.
Levelsensorsactsasfeedbacksensorsforlevelriseaswellasreadingduringfallin
potholes.Therearepressuresensorsaswellwhichareusedasfeedbacksensorfor
maintainingcorrectstiffness.
Stereocamerasensestheroadconditionaround50mfar(dependingon
manufacturer)andECUdeterminestheamountofpressuremaintainedinthe
suspension
TheHydraulicservomechanismactsascountereffectbasedonroadconditions

12. Vehicle performance
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13. Vehicle performance
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14. Vehicle performance
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15. Vehicle performance
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16. Advantages of active suspension
•Roll reduction while cornering
•Pitch reduction during braking and accelerating
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17. Advantages of active suspension
•Camera recognizes the road surface unevenness and adjusts the suspension
•They also prevents axle wrap
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18. Advantages of active suspension
•Detects the side crash and lifts the vehicle by 3-4 inches which will transfer the
load to more reinforced members of vehicle
•Better handling during side winds and less tyre wear
•Ground clearance and height increamentis possible as
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19. Advantages of active suspension
Ground clearance and height increment is possible in case of off road as height
reduction is possible to decrease the Centre of gravity and increase the stability
while cruising
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20. Disadvantages of active suspension
•Costly
•Malfunction may lead to big collapse
•High maintenance
•Added complication
•Difficult to diagnose the error
•Requires super quick on board computers in the vehicle
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21. Vehicles using active suspension
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GMC HUMMER EV
Mercedes s class
Rolls Royce Ghost

22. Audi A8
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23. Mercedes S class
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24. Other Advances
•Active wheel
Michelin'sActive Wheelincorporates an in-wheel electrical suspension
motor that controls torque distribution, traction, turning maneuvers,
pitch, roll and suspension damping for that wheel, in addition to anin-
wheel electric traction motor.
Uses 2 hub motors one for driving and other for suspension
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25. Thank you…..
Presented by INTAKHAB KHAN
VTP2984
Subject-Two and three wheeler technology
Under DR. PADMANABHAN S
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