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Active Suspension Systems

Anthony Griffin

Bradley Rouse

Philip Woodward

MAE 442

Dr. Klang

5/6/2005

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Outline

Common Types of

Suspensions

Active Suspensions

Benefits

Disadvantages

Applications Conclusion

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Common Suspensions

Front Suspension

Solid I-Beam

Twin I-Beam

MacPherson Strut

Short-Long Arm

Rear Suspension

Non Independent

Rear Leaf Springs

Non Independent

RearCoil Springs

Trailing Arm

Beam

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Solid I-Beam

Used on trucks and otherlarge vehicles

Economical Simple design

Low Maintenance

Excellent load capacity

Non-independent design

Uncomfortable ridequality

Poor handling

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Twin I-Beam

Found on many Ford

trucks

Forged, cast, orstamped axles

Excellent load capacity

Requires special

equipment for alignmentadjustments

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MacPherson Strut

One of the mostpopular systems

One Control Arm

Ideal for front wheeldrive

Light weight

Economical

Good ride quality andhandling characteristics

Used for both front andrear suspensions

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Short-Long Arm

Independent design

Uses an upper and alower control arm

Uses either torsionbars or coil springs

Good ride quality andhandlingcharacteristics

Heavy and complexdesign requires a lot ofspace

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Rear Leaf Springs

Non-independent

design

Similar to front solidI-beam axle

Large load carrying

capacity

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RearCoil Springs

Non-independent

design

Uses coils andcontrol arms instead

of leaf springs

Good load carrying

capacity

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Trailing Arm

Independent Design

Uses individual

lower control arms

Uses coil springs

and shocks

Good ride quality

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Rear Beam

Non-independent

design

Stamped beamaxles

Uses coil springs

and trailing arms

Light and simple

design

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Active Suspension Systems

Bose Suspension Magneto-Rheological

Technology

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Bose Suspension System

Electromagneticmotors at each wheel

instead of traditionalshocks and struts.

Sensors at variouslocations to detectbody and suspensionmovement.

Comparison of Factory-Installed and Bose

Suspensions: Body Motion on Bump

Course

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Bose Suspension System

Uses sensor measurements to instantaneously

counteract road forces Produces excellent ride quality and superior

control in the same system

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Bose Suspension Components

Linear Electromagnetic Motor Responds quickly enough to counter the effects of bumps and road

irregularities Power Amplifier

Sends power to the motor during extension and returns power duringretraction

Control Algorithms Observe sensor measurements and send commands to the power

amplifiers

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Bose vs. Stock Suspension

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Magneto-Rheological Technology

Dampers contain magnetic particlessuspended in fluid

Magnetic field within the fluid aligns particles Creates resistance to movement and

increases damping

Variable magnetic field creates more or less

resistance as needed System can change up to 1000 times per

second

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Benefits

Bose Suspension Superior comfort

Superior control

Reduces body roll duringturns

Reduces need for camberroll during turns

Requires only 1/3 of the

power needed by the AC

Wider damping range thanMagneto-Rheologicalsystems

Magnetic Ride Control Improved road handling

Improved wheel control

Smoother ride thanconventional shocks andstruts

Reduces noise andvirbations

Continuous range ofdamping

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Disadvantages

High initial cost

High repair costs

Complex systems

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Applications

Bose Suspension

System will be offered

on high end luxuryvehicles within the

next 5 years.

The same technology

has been applied in

Military applications.

Magnetic Ride Control

Currently offered on

Cadillac SRX and SevilleSTS models.

Offered on the Chevrolet

Corvette for the 2003

model year.

Mercedes S600

BMW 7 series

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Active Military Application

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Conclusion

Active control suspensions offer awider range of comfort and control

than most current suspensionsystems.

Offers unmatched vehicle handlingperformance.

May eventually find their way into morecommon production vehicles.