1. F/O Engineering and Technology Jamia Millia Islamia

2. Independent Suspension
Mahindra Igniters
Independent Suspension
Beam Axle Suspension
Greater ride comfort,
Safer
Stable on/off road
Better traction
Simple in Construction
Inexpensive
Greater loading capacity
Low self weight
F/O Engineering and Technology Jamia Millia Islamia

3. Electromagnetic Suspension System
Mahindra Igniters Solution
Electromagnetic Suspension System
Prepared by
Bilal Hasan Syed
6th Semester
B.Tech Mechanical Engg.
Jamia Millia Islamia

4. Classification of suspension systems
Mahindra Igniters
Classification of suspension systems
Suspension system
Active
Hydraulic
Pneumatic
Electro-magnetic
Passive
F/O Engineering and Technology Jamia Millia Islamia

5. Hydraulic Suspension System
Examples of vehicles employing this technology
BMW has recently developed an antiroll control (BMW-ARC) system by placing a hydraulic rotary actuator in the center of the antiroll bar at the rear of the vehicle as shown on figure in next slide.
Mercedes has developed an Active Body Control System, which uses high-pressure hydraulics to pre-stress the spring, hence generating antiroll forces without coupling the left and right wheels (as in the case of an antiroll bar).
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6. Hydraulic Suspension System
F/O Engineering and Technology Jamia Millia Islamia
Fig no ARC system of BMW using a hydraulic rotary actuator

7. Hydraulic/Pneumatic Suspension System
Mahindra Igniters
Hydraulic/Pneumatic Suspension System
Advantages are
Very high force density
Ease of control
Ease of Design
Commercial availability of various parts
Reliability
Commercial Maturity
F/O Engineering and Technology Jamia Millia Islamia

8. Hydraulic/Pneumatic Suspension System
Mahindra Igniters
Hydraulic/Pneumatic Suspension System
Disadvantages are
considered inefficient due to the required continuously pressurized system;
relatively high system time constant (pressure loss and flexible hoses);
environmental pollution due to hose leaks and ruptures, where hydraulic fluids are toxic;
mass and intractable space requirements of the total system, including supply system, even though it mainly contributes to the sprung mass.
F/O Engineering and Technology Jamia Millia Islamia
Sprung mass – mass of chassis and body wrt to mass of wheels and axle.. Should be low

9. Electro-magnetic Suspension System
Mahindra Igniters
Electro-magnetic Suspension System
Basic Idea
Magnetic repulsion can be used to absorb shocks. And since response to input signals is very fast in electro-magnetic induction motors, its use can give beneficial results.
Linear motion can be achieved by an electric rotary motor with a ball screw or other transducers to transform rotary motion to linear translation. However, the mechanism required to make this conversion introduces significant complications to the system. These complications include backlash and increased mass of the moving part due to connecting transducers or gears that convert rotary motion to linear motion (enabling active suspension).
F/O Engineering and Technology Jamia Millia Islamia
The Motor Principle: when a current-carrying conductor is located in an external magnetic field perpendicular to the conductor, the conductor experiences a force perpendicular to itself and to the external magnetic field.

10. Electro-magnetic Suspension System
Mahindra Igniters
Electro-magnetic Suspension System
Overcomes the disadvantages of hydro/pneumatic suspension as follows-
No need for continuous power,
Ease of control,
Absence of fluids
Relatively high Bandwidth (tens of hertz)
F/O Engineering and Technology Jamia Millia Islamia

11. Bose Suspension System
Mahindra Igniters
Bose Suspension System
- An application of EM suspension
It consists of
Linear electro magnetic motors attached on each wheel,
Power amplifiers at each wheel,
A set of control algorithms.
Working
This linear electromagnetic motor responds quickly enough to counter the effects of bumps and potholes while maintaining a comfortable ride.
Electrical power is delivered to the motor by a power amplifier in response to signals from the control algorithms.
The bidirectional power amplifier allows power to flow into the linear electromagnetic motor and allows power to be returned from the motor.
F/O Engineering and Technology Jamia Millia Islamia

12. Bose Suspension System
Mahindra Igniters
Bose Suspension System
This suspension system requires less than a third of the power of a typical vehicle’s air-conditioning system, i.e., hundreds of watts. Compared with hydraulic actuators, the main advantages of electromagnetic actuators are as follows:
Increased efficiency,
Improved dynamic behavior,
Stability improvement,
Accurate force control,
Dual operation of the actuator.
F/O Engineering and Technology Jamia Millia Islamia
Fast response of EM coil compared to Hydraulic/pneumats. Actuate dampers within fraction of seconds.

13. Bose Suspension System
F/O Engineering and Technology Jamia Millia Islamia
Fig no Bose Suspension System

14. Driving through curves
Mahindra Igniters
Driving through curves
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15. Driving through long Bumps
F/O Engineering and Technology Jamia Millia Islamia

16. Bose Suspension System
Mahindra Igniters
Bose Suspension System
The disadvantages are as follows:
Increased volume of the suspension, since the force density of the active part of hydraulics is higher than for electromagnetic actuation, i.e., system mass and volume could be less;
Relatively high current for a 12- to 14-V system;
Conventional designs that need excitation to provide a continuous force;
Higher system costs.
F/O Engineering and Technology Jamia Millia Islamia
We need to reduce the High cost of the Bose suspension system, so that it can be put into use by normal cost vehicles. What if we can combine the use of active and passive suspension system? This idea can yield to a modified suspension system.

17. Proposed Design Basic Idea
Mahindra Igniters
Proposed Design
Basic Idea
To combine the use of both Active and Passive suspension. The general Macpherson system can be used and the passive shock absorber can be replaced by electromagnetic dampers.
Basic Components
Electromagnetic Damper
Passive Coil Spring
Power supplier
Control Unit
F/O Engineering and Technology Jamia Millia Islamia
To be able to use in a Macpherson type of system, the shape of the magnets have to be changed. The LEM of Bose system doesnt use the coil spring. It simply carves out the shape of the pothole and bump, i.e. the tire extends or withdraws according to the road surface

18. Proposed Design
General Modification For an electromagnetic coil to be used in a Macpherson type of suspension system, its shape has to be modified. F
F/O Engineering and Technology Jamia Millia Islamia
Fig no Linear Electromagnetic coil of Bose System

19. Proposed Design
General Modification It has to be made into a cylindrical shape or moreover a tubular shape so that it can be adjusted in Macpherson system. F
F/O Engineering and Technology Jamia Millia Islamia
Fig no coil shape of the proposed design

20. Proposed Design Coil springs Coil spring Passive damper Permanent
Mahindra Igniters
Proposed Design
Coil
springs
Coil spring
Passive damper
Permanent
magnets
3 phase
Coil
F/O Engineering and Technology Jamia Millia Islamia
Permanent Magnets
So the entire sytem would look like this.
Encoder
Shaft
Bump stop
(A)
(B)
(C)
Fig no Suspension struts. (a) Passive. (b) Active interior-magnet TPMA, (c) Active exterior-magnet TPMA.

21. Mahindra Igniters
Proposed Design
Working When the vehicle moves on the road the irregularities are sensed by the control unit sensors. Power is supplied by the to EM dampers. Signals are sent to Electromagnetic dampers which extend/withdraw according to need. Wheels would then trace the path of irregularity. Entire process would take fractions of second to initiate. The extra shocks would be absorbed by the passive coil spring. Power Regeneration The bidirectional power supplies allows power to flow into the tubular electromagnetic motor and allows power to be returned from the motor. For example, when the suspension encounters a pothole, power is used to extend the motor and isolate the vehicle’s occupants from the disturbance. On the far side of the pothole, the motor operates as a generator and returns the power back through the supplies.
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22. Mahindra Igniters
Proposed Design
Safety In general, the contact with the road surface is increased. When a car turns through corner or curves, the effect of body roll is almost eliminated. This would decrease the chance to topple over the sides making it safer for the passenger. Also the smoother movement of the vehicle, would prevent damage of the mechanical parts. Thus, making safer for the parts of vehicle. Ride-Comfort The fast response of this system, is able to cancel out the vibration up to a very large extent making it very comfortable. Fail Safe Even if the power supply fails, the passive spring would still absorb the shocks and the regenerative power would help run the EM damper.
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Body roll- term used to describe the tilting of cars on other side of the turn taken.

23. Proposed Design Limitation
A lot of research still has to be done to bring this design into usable technology
In general, the entire system installation cost is expected to be quiet high.
Cost Cut-outs
Comparing to Bose system only a shock absorber has to be changed, hence cost compared to Bose sys should be less.
Operating cost is less, since comparatively a low power is required to operate.
Comparing to active hydraulic system, its cost would be very less. (no use of compressors, lesser power consumption)
On observing level of comfort, safety and loading; compensation could be made.
F/O Engineering and Technology Jamia Millia Islamia

24. Conclusion
Active suspension offers many benefits over conventional and semi-active suspension systems
Electromagnetic suspension is a high bandwidth and efficient solution for improving handling and comfort
Proposed design of tubular permanent magnet coil in dampers offers a high force density and fail-safe solution.
F/O Engineering and Technology Jamia Millia Islamia