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
• Suspension system is the system consisting springs, shock absorbers and
having linkages which is used to isolate sprung mass from the road shocks,
vibrations and provide stability. They consist of spring and damper spring
takes the vibrations and dampers reduces thee amplitude of vibration and
damp the vibration.
• Main functions of suspension system are
• To isolate body from road shocks
• To support the weight of the vehicle
• To provide smooth ride
• Allows rapid cornering without extreme body roll
• It helps to maintain the contact between road and tyre.
• Prevent squat during acceleration and dive during braking
• Gives particular height to vehicle body
• Maintains proper steering geometry
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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 stiffness and spring rate improving ride performance, drivability, responsiveness, etc.

5. Difference between passive, semi active and active suspension
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6. Active Suspension
• It is a real time adaptive suspension working on real
time road condition and varying the damping rates as
well as spring rate(changing the travel) as per the need
to offer comfortable ride.
• They use actuator to raise or lower the chassis at each
wheel as per time sensor reading of road condition
• Actuators are controlled by the on board computers
getting the input from sensors
• It "artificially" extends the design parameters of the
system by constantly monitoring and adjusting itself,
thereby changing its character on an ongoing basis.
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7. Components of Active Suspension
• ECU(Electronic control unit) and
ESC(Electronic stability control)
• Stereo camera
• Pump
• Reservoir
• Sensors(Level sensors, speed sensor,
Inertial sensor, 3 axis acceleration
sensor, pressure sensors,
displacement sensors, steering
position sensor)
• Actuators for each suspension(Shock
absorbers with electrically variable
resistance and/or struts that can be
extended or retracted based on
electric signal input.) can be hydraulic
or electromagnetic
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8. Block diagram
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9. Working of active suspension
• Active suspension works by constantly sensing changes in the road surface and
feeding that information, via the ECU, to the outlying components. These
components then act upon the system to modify its character, adjusting shock
stiffness, spring rate and the like, to improve ride performance, drivability,
responsiveness, etc.
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• While taking a turn the vehicle senses it by
steering sensor, speed of wheels and inertial
sensors senses yaw and roll and these signals
are sent to ECU then the ECU sends the signal
to the right servo present at the top of wheels
and increases the stiffness by providing more
amount of pressurized oil to increase the spring
rate and stiffen the suspension in the outer
side to prevent roll.

10. Working of active suspension
• While accelerating or decelerating the inertial
sensor senses it through accelerator pedal input
and wheel speed sensor and manages the
stiffness of the rear or front wheel to prevent
pitching. The feedback is taken from inertial
sensors.
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• While cruising the vehicle height is decreased to
increase the stability by decreasing the centre of
gravity.
• To give the driver comfort there is the height
rise in Audi A8
• When the stereo camera reads any pothole the
wheels and the respective wheels are energized
to increase damping coefficient.

11. Working of active suspension
• In case of side collision height is increased to get the impact
on the portion with highly reinforced part of vehicle.
• While riding off-road as the drivers needs the height
increase the driver can do from the instrumental panel as in
GMC Hummer EV 2022. Level sensors gets the feedback and
correctly maintains the height.(149 mm)
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The three acceleration sensor namely vertical, lateral and longitudinal senses
height rise, side movements and acceleration as well as deceleration respectively.
Level sensors acts as feedback sensors for level rise as well as reading during fall in
potholes. There are pressure sensors as well which are used as feedback sensor for
maintaining correct stiffness.
Stereo camera senses the road condition around 50m far(depending on
manufacturer) and ECU determines the amount of pressure maintained in the
suspension
The Hydraulic servo mechanism acts as counter effect based on road conditions

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 increament is 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's Active Wheel incorporates an in-wheel electrical suspension
motor that controls torque distribution, traction, turning maneuvers,
pitch, roll and suspension damping for that wheel, in addition to an in-
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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