Active Suspension Systems

1
Active Suspension Systems
Anthony Griffin Bradley Rouse Philip Woodward
MAE 442 Dr. Klang 5/6/2005
2
Outline

• Common Types of Suspensions
• Active Suspensions
• Benefits
• Disadvantages
• Applications
• Conclusion

3
Common Suspensions

• Front Suspension
• Solid I-Beam
• Twin I-Beam
• MacPherson Strut
• Short-Long Arm

• Rear Suspension
• Non Independent Rear Leaf Springs
• Non Independent Rear Coil Springs
• Trailing Arm
• Beam

4
Solid I-Beam

• Used on trucks and other large vehicles
• Economical
• Simple design
• Low Maintenance
• Excellent load capacity
• Non-independent design
• Uncomfortable ride quality
• Poor handling

5
Twin I-Beam

• Found on many Ford trucks
• Forged, cast, or stamped axles
• Excellent load capacity
• Requires special equipment for alignment
  adjustments

6
MacPherson Strut

• One of the most popular systems
• One Control Arm
• Ideal for front wheel drive
• Light weight
• Economical
• Good ride quality and handling characteristics
• Used for both front and rear suspensions

7
Short-Long Arm

• Independent design
• Uses an upper and a lower control arm
• Uses either torsion bars or coil springs
• Good ride quality and handling characteristics
• Heavy and complex design requires a lot of space

8
Rear Leaf Springs

• Non-independent design
• Similar to front solid I-beam axle
• Large load carrying capacity

9
Rear Coil Springs

• Non-independent design
• Uses coils and control arms instead of leaf
  springs
• Good load carrying capacity

10
Trailing Arm

• Independent Design
• Uses individual lower control arms
• Uses coil springs and shocks
• Good ride quality

11
Rear Beam

• Non-independent design
• Stamped beam axles
• Uses coil springs and trailing arms
• Light and simple design

12
Active Suspension Systems

• Bose Suspension

• Magneto-Rheological Technology

13
Bose Suspension System

• Electromagnetic motors at each wheel instead of
  traditional shocks and struts.
• Sensors at various locations to detect body and
  suspension movement.

• Comparison of Factory-Installed and Bose
  Suspensions Body Motion on Bump Course

14
Bose Suspension System

• Uses sensor measurements to instantaneously
  counteract road forces
• Produces excellent ride quality and superior
  control in the same system

15
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 during retraction
• Control Algorithms
• Observe sensor measurements and send commands to
  the power amplifiers

16
Bose vs. Stock Suspension
17
Magneto-Rheological Technology

• Dampers contain magnetic particles suspended 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

18
Benefits

• Bose Suspension
• Superior comfort
• Superior control
• Reduces body roll during turns
• Reduces need for camber roll during turns
• Requires only 1/3 of the power needed by the AC
• Wider damping range than Magneto-Rheological
  systems

• Magnetic Ride Control
• Improved road handling
• Improved wheel control
• Smoother ride than conventional shocks and struts
• Reduces noise and virbations
• Continuous range of damping

19
Disadvantages

• High initial cost
• High repair costs
• Complex systems

20
Applications

• Bose Suspension
• System will be offered on high end luxury
  vehicles within the next 5 years.
• The same technology has been applied in Military
  applications.

• Magnetic Ride Control
• Currently offered on Cadillac SRX and Seville STS
  models.
• Offered on the Chevrolet Corvette for the 2003
  model year.
• Mercedes S600
• BMW 7 series

21
Active Military Application
22
Conclusion

• Active control suspensions offer a wider range of
  comfort and control than most current suspension
  systems.
• Offers unmatched vehicle handling performance.
• May eventually find their way into more common
  production vehicles.