Regenerative Suspension System

REGENERATIVE SUSPENSION SYSTEM Project report submitted to Mahatma Gandhi University, Kottayam

in partial fulfillment of the requirements for the award of the degree of

BACHELOR OF TECHNOLOGY IN

MECHANICAL ENGINEERING Submitted by

VINEETH NV(Reg. No.: 11017022)

SNM INSTITUTE OF MANAGEMENT AND TECHNOLOGY, MALIANKARA P O, MOOTHAKUNNAM, N. PARAVOOR, ERNAKULAM-683516

MAHATMA GANDHI UNIVERSITY, KOTTAYAM

NOVEMBER 2014

DEPARTMENT OF MECHANICAL ENGINEERING

SNM INSTITUTE OF MANAGEMENT AND TECHNOLOGY MALIANKARA P O, MOOTHAKUNNAM, N. PARAVOOR, ERNAKULAM-

683516

CERTIFICATE

This is to certify that the project report entitled “REGENERATIVE SUSPENSION

SYSTEM” is a bonafide record of project done by VINEETH NV (Register No.:11017022) in

partial fulfillment of the requirements for the award of degree of Bachelor of Technology in

Mechanical Engineering under Mahatma Gandhi University, Kottayam.

Asst.prof. Arun Narayanan Prof. George Thomas Internal Guide Head of the Department

External Examiner: Internal Examiner:

ACKNOWLEDGEMENT

With great pleasure, I express my deep sense of gratitude to PROF:GEORGE

THOMAS [Head of Mechanical engineering department] for giving his valuable help and

guidance in preparation of my seminar.

I consider it as a great privilege to acknowledge the valuable help rendered by

Asst,Prof.Arun Narayanan [Mechanical engineering department] as my seminar coordinator for

his guidance and encouragement during the course of this seminar.

I express my heartfelt gratitude to Asst.Professor AMAL V K[ Mechanical engineering

department] for his valuable assistance and advices for presenting this seminar.

I also express my thanks to all other faculties of mechanical engineering department for

giving their valuable co-operation.

I express my gratitude to all my friends for their help, co-operation and encouragement.

i

ABSTRACT

This project aims to design and develop a new generation of shock absorbers, specifically, a

regenerative active electromagnetic suspension system for vehicles. Electromagnetic dampers

(EDs) with energy harvesting capabilities will be developed to improve vehicle efficiency,

stability and comfort. The drawbacks in existing variable damper technologies such as the

degradation of Magneto-Rheological (MR) fluids, sealant failure, leakage, performance issues,

and the high cost for MR fluid dampers can be overcome by the proposed EDs. The proposed

EDs are cost-effective and work in non-contact fashion, i.e., extended lifetime of the product.

An ED converts the vibrational energy of a body mass to electrical energy, and acts as sensor

and actuator simultaneously. The use of high-energy permanent magnets, and the regeneration

of vibrational energy, results in self-powered active suspension systems which mitigate the high

energy consumption in ordinary active suspension systems.

The proposed system allows varying damping forces in real-time in response to various driver

and body motion inputs; hence it is effective for both ride and stability control. The suspension

system can operate in passive, semi-active, or active mode. The passive mode is used for fail-

safe operation. The suspension’s damping stiffness in semi-active mode is variable, i.e.,

improving comfort. Improving of vehicle stability is achieved when the suspension system

operates in active mode. Moreover, fuel efficiency is improved when the suspension system acts

as a regenerative device, and several accessories of vehicle can be powered through this

regeneration, reducing the usage of fuel.

ii

CONTENTS

Titles ACKNOWLEDGEMENT……………………………………..…………………....i

ABSTRACT……………………………………………………………………..…..ii

Chapters 1. INTRODUCTION……….………………………………………………………….1

2. TURBOCHARGED DIRECT INJECTION (TDI)………..………….…………....5

2.1. The Technology…………….……………....………………...……………...5

2.2. The Turbocharger……………………………………………..….………….7

2.3. Injection Systems………………………...…….……………..…….…….....8

2.4. Diesel Particulate Filters (DPF)………………………………..…………..11

3. TURBOCHARGED STRATIFIED INJECTION (TSI)…………….………...…...12

3.1. Smaller Engines…………………………….………………..………..…....12

3.2. Twincharging………………….……………………………....……..….…..13

3.3. Charge-Air Intercooling………..…………….……………...……………..15

3.4. Advanced Injection Technology………..…………………..……….…….16

4. DIRECT SHIFT GEARBOX (DSG)……………………………………..……......17

4.1. Working…………………………………………………......…....………..17

4.2. The Technology…………………………..………………..……..…..…....18

4.3. Mechatronics…………………..…………………………..……..….....…18

4.4. DSG 7-Speed Gearbox……………..……………………..……..…….......19

4.5. Dual Clutch…………………..…………………………..……..…….........21

5. AUTOMATIC START/STOP.………….………………………...…..…..…….....22

6. RECUPERATION…………..……..……………………………...……..……..….23

7. GEAR RATIOS…………………...…..………..………………………………....24

8. AERODYNAMICS………………...…………..…..………………………….…..25

9. RESULT & CONCLUSION…..………………...…………..…………………….27

REFERENCE…………………………………………………..………………......28

LIST OF FIGURES

Fig 1. Dismantling study of the Golf V………………………………………………..….4

Fig 2. Comparison between the TDI and normal diesel engine………………………..…10

Fig 3. Schematic diagram of a 7 speed DSG gearbox………………………………….…19

Fig 4. Dual clutch………………………………………………………………….…....…21

Fig 5.Comparison between automobile drag coefficients (Cd)……………………….…26

CHAPTER 1

THE SCOPE FOR PROJECT

In our country due to increased paying capacity, advanced lifestyle and rapidly growing

industrialization, the need & demand of transportation is increasing day- by- day. The number

of vehicles rolling on the road is increasing daily. Hence chances of accidents are increasing

while crossing the road especially by the children and old persons. So it became necessary to

install the speed breakers (in true sense speed reducers) at the school building or Hospital

building- side road or highway. If these speed breakers Yes! In true sense it is speed and

ultimately breaker the opposing impact energy supplied by the hard speed breaker will apply

massive thrust impact on the suspension system of the vehicle. This impact force can be use for

power generation using regenerative method and use to charge battery and release load of

alternator or dynamo from engine.

Here on working this group task we over-come our following needs:-

o We became able to have market survey

o Doped capability of designing a system by collecting necessary data.

o Learnt actual practical fabrication processes of the sub-components of the system.

o Planning the cost estimation and budget.

o Duties of a technician or an Engineer.

1Dept. of Mechanical Engineering SNMIMT Maliankara

CHAPTER 2

SELECTION OF THE PROJECT

We the group of young engineers found that, there is an impending need to make much more

forays to make Non Conventional energy attain popular acclaim. This is also very essential to

preserve the conventional sources of energy and explore viable alternatives like sustainable

energy (the energy which we are already utilizing but for some safety of other uses we are

suddenly wasting it, that can be reutilized), solar, wind and biomass that can enhance

sustainable growth. What is more, such alternatives are environment friendly and easily

replenish able. Therefore, they need to be thoroughly exploited with a functionally expedient,

energy matrix mix.

Growing economies, especially of Asia are gifted with sufficient resource base and non-

conventional energy technologies are consistent both for grid linked energy generation and

transmission in out of the way locates that are landed from the grid. Adaptation of technology

and employing them should be pursued right from this moment to have a head start, be

informed of the barriers in technology applications of the renewable variety and synergizing

them with the existing, traditional power production technology and T&D networks. It is known

that in coming times, wind energy will be the most cost-effective renewable resource. Yet, it is

doubtful if any individual technology would hold centre-stage.

Thus we selected kinetic generator means the “Energy in motion when it is suddenly applied

with a sort of obstacle, then according to Newton’s law for every action there is an equal

and opposite reaction. Utilization of this reaction is the basic reason behind the selection of

this project work.”


CHAPTER 3

INTRODUCTION

It is well fact known that automobiles are inefficient, wasting over 74% of energy stored

in fuel as a heat. Major energy losses are engine losses, idle & standby, braking losses,

aerodynamic drag etc. Thus only 26 % of the available fuel energy is used to drive the

vehicle, i.e. to overcome the resistance from road friction. One important loss is the

dissipation of vibration energy by shock absorbers in the vehicle suspension under the

excitation of road irregularity and vehicle acceleration or deceleration. This paper

presents design and finite element analysis of an electromagnetic energy regenerative

shock absorber which can efficiently recover the vibration energy wasted in vehicle

suspension system. Three alternative methods to recover this waste energy are studied

and compared to get best alternative i.e. electromagnetic system. In this paper ,design

process of electromagnetic energy regenerative shock absorber is explained with due

consideration to space limitations in commercial vehicle. A static magnetic analysis is

used to analyze magnetic field distribution and to obtain optimum design. A preliminary

equation is proposed to predict the generation performance of regenerative shock

absorber depending upon input parameters like flux or velocity. Theoretical studies are

showing that 32 watts of power (8x4 = 32) can be recovered from a vehicle moving with

45 mph speed experiencing 0.25 m/s vertical velocity.

The vehicle manufacturers have made costly strides to improve fuel economy. Car

designers also spend great deal of effort to reduce wind drag so as to improve fuel

economy through streamlined low drag vehicle body design. Manufacturers also use

lighter material to reduce the weight of vehicle and ultimately to reduce fuel

consumption. It is well known that automobiles are inefficient, wasting over 74% of

energy stored in fuel as a heat. Major energy losses are engine losses (62.5%), idle &

standby(17.2%), braking losses (5.8%), rolling resistance(4.2%) & drive line losses

(5.2%), accessory usage(2.5%), aerodynamic drag (2.6%) [10]. To recover energy from

5.8 % braking losses, regenerative braking systems are developed and successfully


implemented in electric vehicles .One important energy loss in automobiles is the

dissipation of vibration energy in vehicle suspension system. When a vehicle travels on

rough road, the vibrations are produced. These vibrations have not been yet considered

for energy recovery and are wasted through conversion into thermal energy. Experiments

have shown that at 90 kmph on good and average roads, 100-400 watts average power is

available to recover in the suspension system of a middle-size vehicle .Middle-size

passenger vehicle requires 180 watt power to operate continuous loads like ignition, fuel

injection and 260 watt power to operate prolonged loads like side & tail lights, head light

main lamp etc. Total power requirement of vehicle to operate its electrical components

sum out to be 180 to 440watts. If all the available vibration energy is recovered, it is

possible to use regenerative shock absorber to charge the battery of vehicle, instead of

alternator. Thus alternator load on vehicle engine can be decreased or removed

completely. If say 3% of fuel efficiency of vehicle is improved by this energy recovery

scheme, by considering number of vehicles in world (value app. In millions), huge

amount of fuel can be saved. Thus energy recovery from suspension system is necessary

to reduces fuel consumption .Eventually it will reduce pollution of air by lesser emission

of pollutant gases.


CHAPTER 4

LITERATURE SURVEY

The research about energy recovery from vehicle suspensions began more than ten years

ago, first as an auxiliary power source for active suspension control, and later also as

energy regenerating devices in their own accord. During the past ten years, energy

recovery from vehicle vibrations has achieved great commercialization success in hybrid

or electric vehicles. Some earlier efforts to recover energy from suspension are-Lei Zuo,

et al.have worked on a prototype design of Electromagnetic energy harvester for vehicle

suspension. In this paper they have designed, characterized and tested a prototype retrofit

regenerative shock absorber. . They fabricated two prototypes of regenerative

electromagnetic shock absorber: a linear device (called as Mark 1) and a rotary device

(called as Mark 2) and installed them in vehicle to study energy recovery. Goldner, et al.

(2001) [3] have carried out a proof-of-concept - to evaluate the feasibility of obtaining

significant energy savings by using regenerative magnetic shock absorber in vehicles.

They proposed electromagnetic (EM) shock absorbers to transform the energy dissipated

in shock absorbers into electrical power. P. Zhang et al. [4]have presented comprehensive

assessment of the power that is available for harvesting in the vehicle suspension system

and the tradeoff among energy harvesting, ride comfort, and road handing with analysis,

simulations and experiments. Zhen Longxinand Wei Xiaogang [5] have modeled the

structure and dimensions of a regenerative electromagnetic shock absorber in CAD

software package. S. Mirzaei.et al [6] introduced a passive suspension system for ground

vehicles based on a flexible Electromagnetic Shock Absorber (EMSA). They designed

and provided a model of passive suspension. Bart Gysenet al., [7] have studied design

aspects of an active electromagnetic suspension system for automotive applications

which combines a brushless tubular permanent-magnet actuator with a passive spring.

N.Bianchi et al [8] have described the design criteria of a tubular linear motor, with

interior permanent magnets. They derived key equations for the analysis


CHAPTER 5

AMOUNT OF ENERGY AVAILABLE FOR RECOVERY IN AVEHICLE

SUSPENSION:-

Although much initial work has been done in regenerative vehicle suspension regarding

the power potential, the fundamental question is still not clear..What is the potential of

harvestable power from suspension system? It is well known fact that shock

absorbers are energy dissipating devices and dissipate vibration energy of vehicle in the

form of heat. Thus it is possible to predict the amount of energy lost in shock absorber in

vertical motion of vehicle. For this purpose, simple spring and mass model is chosen.

When spring compresses and extends due to excitation supplied vehicle vibrations,

energy is stored in the form of strain energy [10]. This energy in compressed spring can

be given by equation –

E =_ ____=___ _²

Using the value of k as ___ __ N/m and supporting vehicle mass approximately

1000 kg [25];vertical displacement stores the amounts of energy in

spring as shown below—

Further on a good city road, vehicle experience vibrations of amplitude 20 mm at a mean

frequency of 2 Hz, keeping in mind that work is done both in compression & extension of

spring, one hour drive will generates 166 watts–hr energy. According to P.Zhang et al,

[4] 100-400 watts power is available from the shock absorbers of a typical middle-size

passenger vehicle at 90 Kmph on the good and average roads. They tested regenerative

shock absorber on a super compact vehicle and found that60 watts energy potential at 40

kmph speed on campus road.


CHAPTER 6

ALTERNATIVE WAYS TO HARVESTENERGY IN VEHICLE

SUSPENSION:-

There are multiple techniques proposed for converting vibration energy of suspension

system to electrical energy called transfer mechanisms. In kinetic energy recovery

scheme, movements, often in the form of vibrations are converted into electrical energy.

Major transfer mechanisms are piezoelectric, hydraulic and electromagnetic .In

piezoelectric system, Peizo electric material is located in top part of damper of

suspension system. When vehicle is excited by road bump, the upward movement of

piston cause fluid to compress and strain is applied on Peizo electric material. Charge

develops across the normal to direction of vehicle displacement. In Hydraulic system,

pressurized oil is passed through small turbine form pipes connected to oil chamber,

causing it to rotate. Advantage of this system is that it can harvest energy in both

expansion and compression cycles of shock absorber. In electromagnetic system is based

on Faraday’s Law of electromagnetic induction. Flux associated with the coils is varied

by movement of wheel, magnetic

flux lines are cut & a voltage is generated. Advantage of this system is that there is no

heat generation due to friction.


CHAPTER 7

COMPARISON TO GET BEST ALTERNATIVE-ELECTROMAGNETIC

SYSTEM

Considering fewer parts for successful operation of energy generation, Peizo electric

method is superior than other two methods. Furthermore it requires less maintenance.

With more than 200 watts of power output, hydraulic system is most efficient out of three

methods. Linear design of electromagnetic energy harvester system makes it possible to

implement in vehicle suspension with minimum design changes .Hydraulic system is

most expensive as it requires number of additional components for successful operation

like turbine, hose pipes, flow meter etc. Main advantage of electromagnetic regenerative

shock absorber is that possible integration with active or semi active suspension system

called Electromagnetic suspension. Based on above points of comparison, it is clear that

electromagnetic energy harvesting system is best suited alternative for suspension

system.


CHAPTER 8

REGENERATIVE ELECTROMAGNETIC SHOCK ABSORBER

A regenerative electromagnetic shock absorber comprising: a linear electromagnetic

generator comprised of a central magnet array assembly comprising a central magnet

array comprised of a plurality of axially-aligned, stacked cylindrical magnets having like

magnetic poles facing one another, a plurality of high magnetic permeability, high

saturation magnetization, centrai cylindrical spacers positioned at each end of said

stacked central magnet array and between adjacent stacked central magnets, and a magnet

array support for mounting said magnets and said spacers; an inner coil array comprising

a plurality of concentric cylindrical coil windings positioned adjacent to said central

spacers and said magnetic poles of said central magnets, said inner coil windings

surrounding an outside perimeter of said central spacers, said inner coil array mounted on

a movable coil support, said movable coil support providing for reciprocating linear

motion of said coil array relative to said magnet array; and an outer magnet array

assembly comprising an outer magnet array comprised of a plurality of axially-aligned,

stacked concentric toroidal magnets having like magnetic poles facing each other, said

outer magnet array surrounding said inner coil array, said stacked outer concentric

magnets being aligned and positioned essentially coplanar with said stacked central

cylindrical magnets with the magnetic poles of said outer magnets aligned with and

facing opposing magnetic poles of said central cylindrical magnets, and a plurality of

high permeability, high saturation magnetization, outer concentric toroidal spacers

positioned at each end of said stacked outer magnet array and between adjacent stacked

outer magnets, said outer magnet array assembly attached to said magnet array support;

wherein a predetermined location, configuration and orientation of said central magnet

magnetic poles, said central spacers, said inner coil windings, said outer magnet magnetic

poles and said outer spacers provide for superposition of a radial component of a


magnetic flux density from a plurality of central and outer magnets to produce a

maximum average radial magnetic flux density in the inner coil windings; and a voltage

conditioning circuit electrically connected to said coil windings, said voltage

conditioning circuit providing an output voltage and output current to an electrical load.

Figure 1.1: Schematic View of electromagneticshock absorber

An electromagnetic linear generator and regenerative electromagnetic shock absorber is

disclosed which converts variable frequency, repetitive intermittent linear displacement

motion to useful electrical power. the innovative device provides for superposition of

radial components of the magnetic flux density from a plurality of adjacent magnets to

produce a maximum average radial magnetic flux density within a coil winding array.

due to the vector superposition of the magnetic fields and magnetic flux from a plurality

of magnets, a nearly four-fold increase in magnetic flux density is achieved over

conventional electromagnetic generator designs with a potential sixteen-fold increase in

power generating capacity. as a regenerative shock absorber, the disclosed device is


http://4.bp.blogspot.com/-Z50iYZavBls/TtcVbilOrMI/AAAAAAAAAG8/sjR1j_eYE-c/s1600/clip_image002.jpg

capable of converting parasitic displacement motion and vibrations encountered under

normal urban driving conditions to a useful electrical. energy for powering vehicles and

accessories or charging batteries in electric and fossil fuel powered vehicles. the

disclosed device is capable of high power generation capacity and energy conversion

efficiency with minimal weight penalty for improved fuel efficiency.


CHAPTER 9

HOW IT WORKS

A conventional automotive shock absorber dampens suspension movement to produce a

controlled action that keeps the tire firmly on the road. this is done by converting the

kinetic energy into heat energy, which is then absorbed by the shock’s oil.

The power-generating shock absorber (pgsa) converts this kinetic energy into electricity

instead of heat through the use of a linear motion electromagnetic system (lmes). the lmes

uses a dense permanent magnet stack embedded in the main piston, a switchable series of

stator coil windings, a rectifier, and an electronic control system to manage the varying

electrical output and dampening load.

The bottom shaft of the pgsa mounts to the moving suspension member and forces the

magnet stack to reciprocate within the annular array of stator windings, producing

alternating current electricity. that electricity is then converted into direct current through

a full-wave rectifier and stored in the vehicle’s batteries.

The electricity generated by each pgsa can then be combined with electricity from other

power generation systems (e.g. regenerative braking) and stored in the vehicle’s batteries.


CHAPTER 10

MANUFACTURING CONSIDERATIONS

Manufacture of the power-generating shock absorber will require a machined main shaft

with embedded permanent magnet stack, a strong air-gap cylinder housing, high quality

stator windings, and robust slide bearings. other systems, such as microprocessor-

controlled voltage, current, and dampening regulation, external casing, protective

bellows, etc. will also need to be designed and tested.


CHAPTER 11

METHODOLOGY

Here following method is adopted to generate the electricity:-

The set up is designed.

It’s subcomponents are manufactured

The sub components are assembled together

The set up is tested for checking whether it performing it’s intended task or not.

Under this method the fly wheel is the key component for energy transformation.

CHAPTER 1214

Dept. of Mechanical Engineering SNMIMT Maliankara

MANUFACTURING OF ELECTROMAGNETICREGENERATIVE SHOCK

ABSORBER

The full scale electromagnetic regenerative shock absorber was fabricated based on the

dimensions derived in above section. The permanent magnets NdFeB (grade N32) were

chosen due to their high magnetic density. Copper wire of 27 AWG were chosen to

wound coils because of its superior conductivity and low resistivity.

Fig 1.5 Exploded view of assembly of components


CHAPTER 13

TESTING OF ELECTROMAGNETIC REGENERATIVE SHOCK

ABSORBER

A test set-up was designed to characterize the voltageoutput and power output of the

generator at variousroad conditions. Shock absorber testing machine was made available

by institute. The machine was having the mechanism for variation of amplitude &

frequency of excitation to simulate road profiles.Waves at different frequencies and

amplitudes weremodeled using mechanism in shock absorber testingmachine.An

oscilloscope was used to measure the outputvoltage, both peak and RMS values, of the

shockabsorber. The oscilloscope was also used to view theoutput waveforms generated

from the shock absorber.A multimeter was used to measure current output.The

regenerated voltage was in alternating currentform and required to be rectified to convert

it intodirect current voltage so as to use in vehicle battery.At a constant frequency (1,2,4

& 6 Hz), inputamplitude was incrementally increased. Outputvoltages were recorded.

Similarly at constantamplitude, frequency is varied to get voltage. Fig 1.6shows a overall

test setup showing prototype, shockabsorber machine, digital storage oscilloscope and

rectifier circuit.


CHAPTER 14

RESULTS AND CONCLUSIONS

The results of experiment carried out for the variation in regenerated voltage against in

excitation frequency& amplitude shows that for input frequency 6 Hz an amplitude 20

mm, cyclic RMS voltage generated for8 coil set of 0º phase and 8 coil set of 90º phase is

5.5& 5.0 volts respectively. The full scale single regenerative shock absorber was able to

harvest 8 W of energy at 0.25–0.5 m s−1 RMS suspension velocity. It was also found that

the frequency of the regenerated voltage does not necessarily have the same frequency as

the excitation. Instead, the wave shapes of the regenerated voltage will depend on

excitation frequency, amplitude and equilibrium position. The overall conclusion of this

research work is that it is possible to harvest energy from vehicle vibrations travelling on

a bumpy road…


REFERENCES

1. Lei Zuo, Brian Scully, Jurgen Shestani and Yu Zhou ,‘Design and characterization of

an electromagnetic energy harvester for vehicle suspensions’, Journal of Smart Materials

and Structures, Volume 19, Number 4.

2. Gupta A, Jendrzejczyk J A, Mulcahy T M and Hull J R ‘Design of electromagnetic

shock absorbers’ ,International Journal of Mechanics & Material Design ,Volume 3,

Number 3.

3. Goldner R B, Zerigian P and Hull J R, ‘A preliminary study of energy recovery in

vehicles by using regenerative magnetic shock absorbers’, SAE Paper#2001-01-2071.

4. Pei-Sheng Zhang and Lei Zuo, ’Energy harvesting, ride comfort, and road handling of

regenerative vehicle suspensions’, ASME Journal of Vibration and Acoustics, 5. Zhen

Longxin and Wei Xiaogang, ‘Structure and Performance Analysis of Regenerative

Electromagnetic Shock Absorber’, Journal of networks, vol. 5, no. 12,December 2010

6. S. Mirzaei, S.M. Saghaiannejad, V. Tahani and M.Moallem, ‘Electromagnetic shock

absorber’ ,Department of Electrical and Computer Engineering ,IEEE 2001.

7. Bart L. J. Gysen, Jeroen L. G. Janssen, Johannes J. H.Paulides, Elena A. Lomonova,

‘Design aspects of an active electromagnetic suspension system for automotive

applications’, IEEE transactions on industry applications, vol. 45, no.

5,September/October 2009 2012.

6. www.howstuffworks.com

7 www.mrfluids.com

8. www.popularmechanics.com

9. En.wikipedia.org


http://www.popularmechanics.com/

http://www.mrfluids.com/

Regenerative Suspension System

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