A

SEMINAR REPORT ON

REGENERATIVE BRAKING SYSTEM

SUBMITTED BY: GUIDED BY: -

ACKNOWLEDGEMENT

Thi s a cknowledgemen t i s a humble a t t emp t t o e a rne s t l y t hank a l l

t hose who we re d i r ec t l y o r i nd i r ec t l y i nvo lved i n p r epa ra t i on o f t h i s

s emina r r epo r t .

I n pa r t i cu l a r I am thank fu l t o my gu ide Mr . Ka lpe sh D . Man ia

who gu ide me i n my semina r work . I am thank fu l t o h im fo r t ak ing

ac t i ve pa r t i n t he p r epa ra t i on o f my semina r r epo r t . I t was imposs ib l e

t o p r e sen t t h i s r epo r t w i thou t h i s co -ope ra t i on and sugges t i on .

Las t bu t no t l e a s t I wou ld l i ke t o exp re s s ou t deep s ense o f

g r a t i t ude t o a l l t he f a cu l t y member s o f Mechan i ca l Eng inee r i ng

Depa r tmen t and a l so my f r i ends who he lp me t o a ccompl i sh wha t I have

s t a r t ed fo r .

DEPARTMENT OF MECHANICAL ENGINEERING

THE SEMINAR REPORT ON :

REGENERATIVE BRAKING SYSTEM

PREPARED BY:

GUIDED BY:

EXAMINER H.O.D

(1) ___________________

(2) ___________________

(3) ___________________

(4) ___________________

ABSTRACT

Regene ra t i ve Brak ing Sys t em i s t he way o f s l owing veh i c l e by u s ing

t he mo to r s a s b r akes . I n s t e ad o f t he su rp lu s ene rgy o f t he veh i c l e

be ing was t ed a s unwan ted hea t , t he mo to r s a c t a s gene ra to r s and r e tu rn

some o f i t t o t he ove rhead w i r e s a s e l e c t r i c i t y .

The veh i c l e i s p r ima r i l y powered f rom the e l e c t r i c a l ene rgy gene ra t ed

f rom the gene ra to r , wh i ch bu rns ga so l i ne . Th i s ene rgy i s s t o r ed i n a

l a rge ba t t e ry , and u sed by an e l e c t r i c mo to r t ha t p rov ide s mo t ive fo r ce

t o t he whee l s . The r egene ra t i ve ba rk ing t ak ing p l ace on t he veh i c l e i s

a way t o ob t a in more e f f i c i ency ; i n s t e ad o f conve r t i ng k ine t i c ene rgy

t o t he rma l ene rgy t h rough f r i c t i ona l b r ak ing , t he veh i c l e c an conve r t a

good f r ac t i on o f i t s k ine t i c ene rgy back i n to cha rge i n t he ba t t e ry ,

u s ing t he s ame p r i nc ip l e a s an a l t e rna to r .

LIST OF FIGURES

Fig . 1 Graph i ca l r ep re sen t a t i on o f ene rgy u sage be tween two veh i c l e s.

Fig . 2 Mercu ry Hybr id Mar ine r

Fig . 3 Regene ra t i ve Brak ing Sys t em Us ing N i t i no l Sp r ing .

CONTENTS

1. INTRODUCTION

2. NECESSITY OF THE SYSTEM

3. REGENRATIVE BRAKE

4. ELEMENTS OF THE SYSTEM

5. DESCRIPTION & OPERATION

6. RESULTS

7. CONCLUSION

CHAPTER 1: INTRODUCTION

Brake : -

A b rake i s a mach ine e l emen t and i t s p r i nc ip l e ob j ec t i s t o abso rb

ene rgy du r ing dece l e r a t i on . I n veh i c l e b r akes a r e u sed t o abso rb

k ine t i c ene rgy whe rea s i n ho i s t s o r e l eva to r s b r akes a r e a l so u sed t o

abso rb po t en t i a l ene rgy . By connec t i ng t he mov ing member t o

s t a t i ona ry f r ame , no rma l ly b r ake conve r t s k ine t i c ene rgy t o hea t

ene rgy . Th i s c ause s was t age o f ene rgy and a l so wea r ing o f f r i c t i ona l

l i n ing ma te r i a l .

Regenera t ive Brak ing Sys tem: -

Regene ra t i ve Brak ing Sys t em i s t he way o f s l owing veh i c l e by

u s ing t he mo to r s a s b r akes . I n s t e ad o f t he su rp lu s ene rgy o f t he

veh i c l e be ing was t ed a s unwan ted hea t , t he mo to r s a c t a s gene ra to r s

and r e tu rn some o f i t t o t he ove rhead w i r e s a s e l e c t r i c i t y .

The veh i c l e i s p r ima r i l y powered f rom the e l e c t r i c a l ene rgy gene ra t ed

f rom the gene ra to r , wh i ch bu rns ga so l i ne . Th i s ene rgy i s s t o r ed i n a

l a rge ba t t e ry , and u sed by an e l e c t r i c mo to r t ha t p rov ide s mo t ive fo r ce

t o t he whee l s . The r egene ra t i ve ba rk ing t ak ing p l ace on t he veh i c l e i s

a way t o ob t a in more e f f i c i ency ; i n s t e ad o f conve r t i ng k ine t i c ene rgy

t o t he rma l ene rgy t h rough f r i c t i ona l b r ak ing , t he veh i c l e c an conve r t a

good f r ac t i on o f i t s k ine t i c ene rgy back i n to cha rge i n t he ba t t e ry ,

u s ing t he s ame p r i nc ip l e a s an a l t e rna to r .

The re fo re , i f you d r i ve l ong d i s t ance w i thou t b r ak ing , you ’ l l be

power ing t he veh i c l e en t i r e l y f rom gaso l i ne . The r egene ra t i ve b r ak ing

Regene ra t i ve Brak ing Sys t em comes i n to i t s own when you ’ r e d r i v ing

i n t he c i t y , and spend ing a good dea l o f you r t ime b rak ing .

You w i l l s t i l l u se more fue l i n t he c i t y fo r e ach mi l e you d r i ve t han on

t he h ighway , t hough . (The rmodynamics t e l l s u s t ha t a l l i ne f f i c i ency

comes f rom hea t gene ra t i on . Fo r i n s t ance , when you b r ake , t he b r ake

peda l s hea t up and a quan t i t y o f hea t , o r ene rgy , i s l o s t t o t he ou t s i de

wor ld . F r i c t i on i n t he eng ine p roduces hea t i n t he s ame way .

Hea t energy , a lso , has h igher en t ropy than , say , e lec t r i c ,

mean ing tha t i t i s less o rdered . )

Def in i t i on :

Brak ing me thod i n wh ich t he mechan i ca l ene rgy f rom the l oad i s

conve r t ed i n to e l e c t r i c ene rgy and r egene ra t ed back i n to t he l i ne

i s known a s Regene ra t i ve Brak ing . The Moto r ope ra t e s a s

gene ra to r .

Regenera t ive Brak ing For Hybr id Veh ic l e :

In mos t e l e c t r i c and hyb r id e l e c t r i c veh i c l e s on t he road t oday ,

t h i s i s a ccompl i shed by ope ra t i ng t he t r a c t i on mo to r a s a gene ra to r ,

p rov id ing b r ak ing t o rque t o t he whee l s and r echa rg ing t he t r a c t i on

ba t t e r i e s . The ene rgy p rov ided by r egene ra t i ve b r ak ing can t hen be

u sed fo r p ropu l s i on o r t o power veh i c l e a cce s so r i e s .

CHAPTER 2: NECESSITY OF THE SYSTEM

The r egene ra t i ve b r ak ing sy s t em de l i ve r s a number o f s i gn i f i c an t

advan t ages ove r a c a r t ha t on ly ha s f r i c t i on b r akes . I n l ow-speed , s t op -

and -go t r a f f i c whe re l i t t l e dece l e r a t i on i s r equ i r ed ; t he r egene ra t i ve

b r ak ing sy s t em can p rov ide t he ma jo r i t y o f t he t o t a l b r ak ing fo r ce .

Th i s va s t l y improves fue l e conomy wi th a veh i c l e , and fu r t he r enhances

t he a t t r a c t i venes s o f veh i c l e s u s ing r egene ra t i ve b r ak ing fo r c i t y

d r i v ing . A t h ighe r speeds , t oo , r egene ra t i ve b r ak ing ha s been shown to

con t r i bu t e t o improved fue l e conomy – by a s much a s 20%.

Cons ide r a heavy l oaded t r uck hav ing ve ry f ew s tops on t he road .

I t i s ope ra t ed nea r max imum eng ine e f f i c i ency . The 80% o f t he ene rgy

p roduced i s u t i l i z ed t o ove rcome the ro l l i ng and ae rodynamic road

fo r ce s . The ene rgy was t ed i n app ly ing b r ake i s abou t 2%. A l so i t s

b r ake spec i f i c f ue l consumpt ion i s 5%.

Now cons ide r a veh i c l e , wh i ch i s ope ra t ed i n t he ma in c i t y whe re

t r a f f i c i s a ma jo r p rob l em he re one ha s t o app ly b r ake f r equen t l y . Fo r

such veh i c l e s t he was t age o f ene rgy by app l i c a t i on o f b r ake i s abou t

60% to 65%. And a l so i t i s i ne f f i c i en t a s i t s b r ake spec i f i c f ue l

consumpt ion i s h igh .

HEAVY LOADED TRUCK CITY BUS

2.1 Graphical representation of energy usage between two vehicles.

Road 80%

Other18%

Rake 65%

Road 26%

Brake 2% other 9%

Some of the advantages of regenerat ive braking over

convent ional braking are as fo l lows:

Energy Conserva t ion :

The f l ywhee l abso rbs ene rgy when b rak ing v i a a c l u t ch sy s t em s lowing

t he ca r down and speed ing up t he whee l . To acce l e r a t e , ano the r c l u t ch

sy s t em connec t s t he f l ywhee l t o t he d r i ve t r a i n , speed ing up t he ca r and

s l owing down the f l ywhee l . Ene rgy i s t he r e fo re conse rved r a the r t han

was t ed a s hea t and l i gh t wh ich i s wha t no rma l ly happens i n t he

con t empora ry shoe /d i s c sy s t em.

Wear Reduc t ion :

An e l ec t r i c d r i ve t r a i n a l so a l l ows fo r r egene ra t i ve b r eak ing wh ich

i nc r ea se s E f f i c i ency and r educes wea r on t he veh i c l e b r akes . I n

r egene ra t i ve r ak ing , when t he mo to r i s no t r e ce iv ing power f rom the

ba t t e ry pack , i t r e s i s t s t he t u rn ing o f t he whee l s , c ap tu r i ng some o f t he

ene rgy o f mo t ion a s i f i t we re a gene ra to r and r e tu rn ing t ha t ene rgy t o

t he ba t t e ry pack . I n mechan i ca l b r akes ; l e s s en ing wea r and ex t end ing

b r ake l i f e i s no t pos s ib l e . Th i s r educes t he u se o f u se t he b r ake .

Fue l Consumpt ion:

The fue l consumpt ion o f t he conven t i ona l veh i c l e s and r egene ra t i ve

b r ak ing sy s t em veh i c l e s was eva lua t ed ove r a cou r se o f va r i ous f i xed

u rban d r i v ing s chedu l e s . The r e su l t s a r e compa red a s shown in f i gu re .

Rep re sen t i ng t he s i gn i f i c an t cos t s ay ing t o i t s owne r , i t h a s been

p roved t he r egene ra t i ve b r ak ing i s ve ry fue l - e f f i c i en t .

Brak ing i s no t to ta l l o s s :

Conven t i ona l b r akes app ly f r i c t i on t o conve r t a veh i c l e ’ s k ine t i c

ene rgy i n to hea t . I n ene rgy t e rms , t he r e fo re , b r ak ing i s a t o t a l l o s s :

once hea t i s gene ra t ed , i t i s ve ry d i f f i cu l t t o r euse . The r egene ra t i ve

b r ak ing sy s t em, howeve r , s l ows a veh i c l e down in a d i f f e r en t way .

CHAPTER 3 :REGENERATIVE BRAKING SYSTEM.

A regenerative brake is an apparatus, a device or system which allows a vehicle to recapture and store part of the kinetic energy that would otherwise be 'lost' to heat when braking.

The IMA operating principle

Honda ' s pa ten ted IMA concep t i s qu i t e s imple - use an e f f i c i en t Ot to eng ine supp lemented by an e lec t r i c motor when add i t iona l power i s needed . Also re fe r red to as a ' hybr id ' sys tem because i t uses two power sources , the IMA concep t a l lows the Civ ic Hybr id to use a smal le r gaso l ine eng ine wi thou t any s ign i f i can t loss in pe r fo rmance .

Th i s sys tem i s e spec ia l ly e f fec t ive due to the fac t tha t acce le ra t ion requ i res a s ign i f i can t ly h igher power than needed fo r c ru i s ing on a l eve l road (where veh ic les spend mos t o f the i r t ime) . An eng ine more power fu l than needed has to work under low load mos t o f the t ime , cond i t ion where i t s e f f i c i ency i s lower than under h igh loads , thus worsen ing the veh ic le ' s fue l economy. .

The e lec t r i c motor -genera to r pos i t ioned be tween the eng ine and t r ansmiss ion ass i s t s the eng ine when acce le ra t ing and recovers energy to s to re in ba t t e r i e s when b rak ing o r dece le ra t ing ( regenera t ive b rak ing) , a l lowing i t to opera te independen t ly wi thou t the need fo r a g r id power supp ly .

When the Civ ic Hybr id i s coas t ing o r i t s b rakes a re app l i ed , i t s e l ec t r i c motor becomes a genera to r , conver t ing fo rward momentum (k ine t i c ene rgy ) i n to e l e c t r i c a l ene rgy , i n s t e ad o f was t i ng i t a s hea t du r ing conven t i ona l b r ak ing . Ene rgy i s s t o r ed i n a ba t t e ry pack l oca t ed beh ind t he r e a r s ea t i n t he t r unk . I f t he s t a t e o f cha rge o f t he ba t t e r i e s i s l ow , t he mo to r -gene ra to r w i l l a l so r e cha rge t hem wh i l e t he C iv i c Hybr id i s c ru i s i ng .

CHAPTER 4: ELEMENTS OF THE SYSTEM

The re a r e t h r ee ba s i c e l emen t r equ i r ed wh ich a r e nece s sa ry fo r t he

work ing o f r egene ra t i ve b r ak ing sy s t em, t he se a r e :

1 .Energy S torage Un i t (ESU) :

The ESU pe r fo rms two p r ima ry func t i ons

1 .TO r ecove r & s to r e b r ak ing ene rgy

2 . TO abso rb exce s s eng ine ene rgy du r ing l i gh t l oad ope ra t i on

The s e l ec t i on c r i t e r i a f o r an e f f ec t i ve ene rgy s t o r age i nc ludes

1 . H igh spec i f i c ene rgy s t o r age dens i t y

2 . H igh ene rgy t r ans f e r r a t e

3 . Sma l l space r equ i r emen t

The ene rgy r ecap tu red by r egene ra t i ve b r ak ing migh t be s t o r ed i n one

o f t h r ee dev i ce s : an e l e c t rochemica l ba t t e ry , a f l ywhee l , i n a

r egene ra t i ve fue l c e l l .

Regen and Bat t er i e s :

With t h i s sy s t em, t he e l e c t r i c mo to r o f a c a r becomes a gene ra to r when

t he b r ake peda l i s app l i ed . The k ine t i c ene rgy o f t he c a r i s u sed t o

gene ra t e e l e c t r i c i t y t ha t i s t hen u sed t o r e cha rge t he ba t t e r i e s . Wi th

t h i s sy s t em, t r ad i t i ona l f r i c t i on b r akes mus t a l so be u sed t o ensu re t ha t

t he c a r s l ows down a s much a s nece s sa ry . Thus , no t a l l o f t he k ine t i c

ene rgy o f t he c a r c an be ha rne s sed fo r t he ba t t e r i e s because some o f i t

i s " l o s t " t o was t e hea t . Some ene rgy i s a l so l o s t t o r e s i s t ance a s t he

ene rgy t r ave l s f rom the whee l and ax l e , t h rough t he d r i ve t r a in and

e l ec t r i c mo to r , and i n to t he ba t t e ry . Fo r example , t he Toyo t a P r i u s c an

on ly r ecap tu re abou t 30% o f t he veh i c l e s k ine t i c ene rgy .

The Honda In s igh t i s ano the r veh i c l e i n add i t i on t o t he P r i u s t ha t i s on

t he ma rke t and cu r r en t l y u se s r egene ra t i ve b r ak ing . I n t he In s igh t t he r e

a r e two dece l e r a t i on modes : When t he t h ro t t l e i s engaged , bu t t he b r ake

peda l i s no t , t he veh i c l e s l ows down g radua l l y , and t he ba t t e ry r e ce ive s

a pa r t i a l cha rge .

When the b r ake peda l i s dep re s sed , t he ba t t e ry r e ce ive s a h ighe r

cha rge , wh ich s l ows t he veh i c l e down f a s t e r . The fu r t he r t he

b r ake peda l i s dep re s sed , t he more t he conven t i ona l f r i c t i on

b r akes a r e emp loyed .

I n t he In s igh t , t he mo to r /gene ra to r p roduces AC, wh ich i s conve r t ed

i n to DC, wh ich i s t hen u sed t o cha rge t he Ba t t e ry Modu le . The In s igh t ,

a s we l l a s a l l o t he r r egene ra t i ve sy s t ems , mus t have an e l e c t r i c

con t ro l l e r t ha t r egu l a t e s how much cha rge t he ba t t e ry r e ce ive s and how

much t he f r i c t i on b r akes a r e u sed .

Regen and F lywhee l s :

In t h i s sy s t em, t he t r ans l a t i ona l ene rgy o f t he veh i c l e i s t r ans f e r r ed

i n to ro t a t i ona l ene rgy i n t he f l ywhee l , wh i ch s t o r e s t he ene rgy un t i l i t

i s needed t o a cce l e r a t e t he veh i c l e . The bene f i t o f u s ing f l ywhee l

t e chno logy i s t ha t more o f t he fo rwa rd i ne r t i a l ene rgy o f t he c a r c an be

cap tu r ed t han i n ba t t e r i e s , because t he f l ywhee l c an be engaged even

du r ing r e l a t i ve ly sho r t i n t e rva l s o f b r ak ing and acce l e r a t i on . I n t he

c a se o f ba t t e r i e s , t hey a r e no t ab l e t o a ccep t cha rge a t t he se r ap id

i n t e rva l s , and t hus more ene rgy i s l o s t t o f r i c t i on . Ano the r advan t age

o f f l ywhee l t e chno logy i s t ha t t he add i t i ona l power supp l i ed by t he

f l ywhee l du r ing acce l e r a t i on subs t an t i a l l y supp l emen t s t he power

ou tpu t o f t he sma l l eng ine t ha t hyb r id veh i c l e s a r e equ ipped w i th .

2 . Cont inuous ly Var iab l e Transmis s ion (CVT) :

The ene rgy s t o r age un i t r equ i r e s a t r ansmi s s ion t ha t c an hand l e

t o rque and speed demands i n a s t e ep l e s manne r and smoo th ly con t ro l

ene rgy f l ow to and f rom the veh i c l e whee l s . Fo r t he f l ywhee l t he

con t i nuous ly va r i ab l e t r ansmi s s ion and veh i c l e because f l ywhee l

r o t a t i ona l speed i nc r ea se s when veh i c l e speed dec rea se s and v i ce ve r sa .

F lywhee l c an work we l l w i th e i t he r mechan i ca l o r hyd ros t a t i c

con t i nuous ly va r i ab l e t r ansmi s s ion .

3 . Contro l Sys t em :

An “ON-OFF” eng ine con t ro l sy s t em i s u sed . Tha t means t ha t t he

eng ine i s “ON” un t i l t he ene rgy s t o r age un i t ha s been r eached t he

de s i r ed cha rge capac i t y and t hen i s decoup l ed and s t opped un t i l t he

ene rgy s t o r age un i t cha rge f a l l be low i t s m in imum requ i r emen t .

CHAPTER5: DESCRIPTION & OPERATION

How regenera t ive brak ing sys t em works?

Regene ra t i ve (o r Dynamic Brak ing ) occu r s when t he veh i c l e i s i n

mo t ion , such a s coa s t i ng , t r ave l i ng downh i l l o r b r ak ing . And t he

acce l e r a to r peda l i s no t be ing dep re s sed . Dur ing “Regen t , ” t he mo to r

becomes a gene ra to r and s ends ene rgy back t o t he ba t t e r i e s .

I t i s exp l a ined a s fo l l ows , because t he whee l s o f a dece l e r a t i ng

veh i c l e a r e s t i l l mov ing fo rwa rd , t hey can be made t o t u rn t he e l e c t r i c

mo to r , wh i ch t hen f eeds ene rgy t o t he ba t t e r i e s f o r s t o r age . The

sy s t em becomes , i n e f f ec t , a gene ra to r , wh i ch p rov ide s b r ak ing fo r ce

wh i l e i t conve r t s t he veh i c l e ’ s k ine t i c ene rgy i n to a r eusab l e fo rm-

e l e c t r i c a l ene rgy .

When t he acce l e r a to r peda l i s r e l e a sed , t he absence o f p r e s su re

t r i gge r s a r e sponse f rom the Ene rgy S to r age Un i t (ESU) . Regene ra t i ve

b r ak ing beg in s , and t he ba t t e r i e s a r e r e - cha rged by t he mo to r , wh i ch i s

t u rned by t he whee l s . I n t h i s c a se , t he f r i c t i on b r akes a r e no t engaged .

I f more v igo rous dece l e r a t i on i s r equ i r ed , and t he b r ake peda l i s

dep re s sed , t h i s engages bo th s e t s o f b r akes . Howeve r , t o max imize

ene rgy e f f i c i ency , i t i s advan t ageous t o app ly t he r egene ra t i ve b r ake a s

such a s pos s ib l e – i t t he r e fo re t ends t o do more o f i t s t o t a l work i n t he

f i r s t pa r t o f t he b r ak ing mo t ion .

The re a r e two dece l e r a t i on modes :

1 . Foo t o f f t h ro t t l e bu t no t on b r ake peda l – i n t h i s mode , t he

cha rge / a s s i s t gauge w i l l show pa r t i a l cha rge , and t he veh i c l e w i l l s l ow

down g radua l l y .

2 . Foo t on b r ake peda l - I n t h i s mode , a h ighe r amoun t o f r egene ra t i on

w i l l be a l l owed , and t he veh i c l e w i l l s l ow more r ap id ly . Dur ing l i gh t

b r ake peda l app l i c a t i on , on ly t he IMA moto r / / gene ra to r i s s l owing t he

ca r . Wi th heav i e r b r ake peda l app l i c a t i on , t he conven t i ona l f r i c t i on

b r akes a l so come i n to p l ay . When dece l e r a t i ng , r egene ra t i on w i l l

con t i nue u8n t i l eng ine speed f a l l s t o abou t 1000 rpm. A t t h i s po in t ,

t he d r i ve r w i l l t yp i ca l l y sh i f t i n t o neu t r a l .

EXAMPLE

Mercury Hybrid Mariner

1 . Mercury Mar iner Hybr id Produc t i on Pu l l ahead : P roduc t i on beg in s a yea r

ahead o f s chedu l e Growing t he Mercu ry Brand : New mode l s and goa l s Dis t i nc t i ve Des ign : Mar ine r f e a tu r e s c l e an l i ne s , c a r e fu l

c r a f t smansh ip Power P l ay : Fu l l -hyb r id ga so l i ne and e l ec t r i c power t r a in Dynamic Chas s i s : N imb le hand l i ng and a smoo th , qu i e t r i de Dis t i ngu i shed Sa fe ty : Fu l l a r r ay o f s a f e ty f e a tu r e s Green Mis s ion : Fo rd Moto r Company ' s s t r a t egy fo r su s t a inab i l i t y

i n veh i c l e s

The Mercu ry Mar ine r Hybr id o f f e r s a un ique ly s a t i s fy ing t r anspo r t a t i on cho i ce fo r an eve r - i nc r ea s ing s egmen t o f t he popu l a t i on conce rned abou t t he env i ronmen t . I t ' s a s t y l i sh , upsca l e spo r t -u t i l i t y veh i c l e w i th n imb le hand l i ng and impre s s ive pe r fo rmance , a s we l l a s amp le ca rgo and t owing capac i t y . I n add i t i on , i t ' s an env i ronmen ta l l y consc ious SUV wi th r emarkab l e fue l e conomy – an e s t ima t ed 33 mi l e s pe r ga l l on (mpg) c i t y , 29 mpg h ighway – and i s expec t ed t o mee t t he c l e anes t emi s s ions r a t i ng ach i evab l e by a fo s s i l - f ue l veh i c l e (Ca l i fo rn i a ' s Advanced Techno logy Pa r t i a l Ze ro Emis s ions Veh i c l e s t anda rd ) .

Eng inee r s p l aced t he add i t i ona l hyb r id power t r a in componen t s l ow and t o t he r e a r , t o l ower t he c en t e r o f g r av i t y and improve t he conven t i ona l Mar ine r ' s f r on t - r ea r we igh t d i s t r i bu t i on .

The r ack -and -p in ion s t e e r i ng i s e l e c t r i c a l l y a s s i s t ed , r a t he r t han u s ing t he t r ad i t i ona l hyd rau l i c s t e e r i ng pump fo r cons i s t en t s t e e r i ng e f fo r t s and con t ro l whe the r t he ga so l i ne eng ine i s s t opped o r r unn ing . Regene ra t i ve b r ak ing u se s t he t r a c t i on mo to r t o a s s i s t t he fou r -whee l d i s c b r akes i n s l owing Mar ine r Hybr id wh i l e s imu l t aneous ly gene ra t i ng e l e c t r i c i t y fo r cha rg ing t he ba t t e ry .

Regenera t ive brak ing o f Toyota Pr ius :

Toyo ta r e a l i z ed t ha t one way t o a ch i eve l onge r veh i c l e r ange was

t o conse rve and r euse some o f t he ene rgy t ha t a veh i c l e no rma l ly l o se s

a s hea t c aused by b r ak ing f r i c t i on . Th i s i dea l ed eng inee r s t o app ly t he

p r i nc ip l e s o f r egene ra t i ve b r ak ing .

In a l l Toyo t a veh i c l e s t ha t f e a tu r e t he r egene ra t i ve b r ak ing

sy s t em, t he r egene ra t i ve b r ake i s on ly r e spons ib l e fo r a pa r t o f t he

dece l e r a t i on nece s sa ry t o s t op t he veh i c l e . I n an EV, t h i s f r a c t i on i s

de t e rmined by t he veh i c l e ’ s speed when b rak ing i s i n i t i a t ed . The

r ema in ing b r ak ing fo r ce i s p rov ided by t he veh i c l e ’ s f r i c t i on b r akes .

To max imize fue l e conomy , o f cou r se , t he r egene ra t i ve b r ak ing sy s t em

i s made t o do a s much o f t he b r ak ing work a s pos s ib l e .

Component Used in Toyota Pr ius for Regenera t ive Brak ing Sys tem:

Brake Peda l :

I t i s u sed t o app ly b r ak ing fo r ce by t he d r i ve r .

Hydrau l i c Boos t e r Un i t :

I t i s composed o f t he mas t e r cy l i nde r and t he r egu l a to r , r e sponds i n

two s t eps . F i r s t i t s i gna l s e l e c t ron i ca l l y t o t he b r ake ECU tha t b r ak ing

fo r ce ha s been demanded . Nex t , t he mas t e r cy l i nde r exe r t s hyd rau l i c

p r e s su re on t he peda l s t r oke s imu la to r , and t he r egu l a to r f e eds

hyd rau l i c f l u id t o t he hyd rau l i c p r e s su re con t ro l un i t .

Brake ECU:

The b rake ECU sense s t he b r ak ing demand and s ends a f r a c t i on o f t h i s

demand t o t he THSECU fo r r egene ra t i ve b r ak ing .

I t a l so ca l cu l a t e s t he fo r ce nece s sa ry t o fu l f i l l r ema in ing b r ak ing

demand and i n s t ruc t t he hyd rau l i c p r e s su re con t ro l un i t t o pa s s on a

co r r e spond ing amoun t o f hyd rau l i c f l u id

Peda l S t roke S imula to r :

I t ab so rbs an amoun t o f hyd rau l i c p r e s su re f rom mas t e r cy l i nde r t ha t

co r r e sponds t o t he amoun t o f b r ak ing fo r ce app l i ed by t he r egene ra t i ve

b r ak ing sy s t em.

As hyd rau l i c p r e s su re i s f ed back t o t he peda l , t he peda l , t he

peda l s t r oke s imu la to r f e eds back t o t he mas t e r cy l i nde r .

THS (Toyo ta Hybr id Sys t em) ECU:

I t i nduces r egene ra t i ve b r ak ing , and r e tu rns a s i gna l t ha t i nd i ca t e s

b r ak ing fo r ce ou tpu t back t o t he b r ake ECU.

Hydrau l i c Pre s sure Con t ro l Un i t :

I t pa s se s on a co r r e spond ing amoun t o f hyd rau l i c f l u id t o a f ou r way

cy l i nde r .

CHAPTER 6: RESULT

Regene ra t i ve b r ak ing t e chno logy i s one more pos i t i ve s t ep

fo rwa rd i n Toyo t a ’ s ques t t o r e a l i z e t he u l t ima t e e coca r . By work ing i n

conce r t w i th p r ev ious ly deve loped e l ec t r i c mo to r t e chno log i e s , i t s

app l i c a t i on he lp s Toyo t a ’ s e l e c t r i c veh i c l e s and hyb r id veh i c l e s

( i nc lud ing t he r e cen t l y r e l e a sed p r i u s ) t o a ch i eve ex t ended r anges and

t o be f r i end l i e r t o t he env i ronmen t t han eve r be fo re . A t t he s ame t ime ,

t h i s new t echno logy r ema ins unob t ru s ive ly i n t he backg round ; d r i ve r s

bene f i t f r om r egene ra t i ve b r ak ing wh i l e en joy ing t he s ame f i rm b rak ing

f ee l f ound i n conven t i ona l l y equ ipped veh i c l e s .

7.1 Regenerative braking system using Nitinol Spring

Wheel

Rotating Device.

Shafts.

Gearbox Clutch Spring

Wheel – ARotating Device – BShafts – C.D. Gearbox –EClutch – GSpring - H

A hydraulic regenerative braking system improves the fuel economy of Ford's F-350 Tonka 25-35% during stop-and-go driving. The system provides power  during initial acceleration when demand peaks.

The HLA sys t em cons i s t s o f a r eve r s i b l e hyd rau l i c pump/mo to r f rom Ea ton ' s F lu id Power Group (Eden P ra i r i e , MN) coup l ed t o t he d r i ve sha f t t h rough a c l u t ch and two accumula to r s . As t he d r i ve r s t eps on t he b r ake , t he pump/mo to r fo r ce s hyd rau l i c f l u id ou t o f a l ow-p re s su re a ccumula to r and i n to a h igh -p re s su re a ccumula to r , i nc r ea s ing t he p r e s su re o f n i t r ogen ga s s t o r ed t he r e t o 5 ,000 p s i .

Dur ing acce l e r a t i on , t he HLA sys t em swi t ches f rom the pump mode t o t he mo to r mode , t he n i t r ogen ga s fo r ce s t he hyd rau l i c f l u id back i n to t he l ow-p re s su re a ccumula to r , and t he pump/mo to r app l i e s t o rque t o t he d r i ve sha f t t h rough t he c lu t ch . I f qu i ck acce l e r a t i on i s r equ i r ed , t he F -350 ' s d i e se l eng ine works w i th t he HLA sys t em

The hydrau l i c l aunch a s s i s t s y s t em in t he F -350 Tonka f unc t i ons a s a s econdary source o f ene rgy dur ing peak power demand . I t cons i s t s o f a l ow-pre s sure accumu la to r i n b lue , and a h igh -pre s sure accumu la to r i n r ed . The s y s t em cap ture s ene rgy norma l l y d i s s i pa t ed a s hea t dur ing b reak ing , s t o re s i t , and u se s i t l a t e r dur ing pe r iods o f peak power demand .

Eigh ty pe r cen t o f t he i n i t i a l k ine t i c ene rgy i s r e t u rned t o t he veh i c l e . "The sy s t em s to r e s app rox ima te ly 380 k J o f ene rgy , " s ays B rad Boh lmann , a mechan i ca l eng inee r and bus ine s s deve lopmen t coo rd ina to r i n Advanced Techno logy a t Ea ton ' s F lu id Power Group . "Wi th t ha t much ene rgy , we can acce l e r a t e a 10 ,000 - lb veh i c l e f rom a dead s t op t o be tween 25 and 30 mi l e s pe r hou r w i th no a s s i s t ance f rom the veh i c l e ' s combus t i on eng ine . "

"Fo rd t h inks t ha t bo th e l e c t r i c and hyd rau l i c r egene ra t i ve sy s t ems have a fu tu r e , " s ays John Brev i ck , a Fo rd mechan i ca l eng inee r work ing on t he HLA sys t em. "Bu t fo r heavy veh i c l e s l i ke ou r 10 ,000 - lb F -350 t rucks , hyd rau l i c s a r e be t t e r a t c ap tu r i ng l o s t ene rgy t han e l ec t r i c sy s t ems . "

Ea ton ' s Boh lmann exp l a in s t ha t t he r e a l advan t age o f hyd rau l i c s i s i n i t s power dens i t y . "Hydrau l i c s i s c apab l e o f t r ans f e r r i ng ene rgy ve ry qu i ck ly , " s ays Boh lmann . "The r a t e o f ene rgy t r ans f e r i s i n a hyb r id e l e c t r i c sy s t em o f a s im i l a r s i z e i s much l ower . "

Boh lmann adds t ha t t he spec i f i c voca t i on o r d r i v ing cyc l e o f t he veh i c l e de t e rmines whe the r a hyb r id hyd rau l i c o r hyb r id e l e c t r i c sy s t em i s be s t su i t ed fo r t he veh i c l e . "Th ink o f hyd rau l i c s a s a sp r i n t e r , p rov id ing f a s t bu r s t s o f power , " he s ays . "An e l ec t r i c hyb r id i s more l i ke a ma ra thon runne r . "

"The cha l l enge now i s t o make u se o f t he r egene ra t i ve b r ak ing sy s t em seamle s s t o t he cus tomer , " s ays Fo rd ' s B rev i ck . "We s t i l l h ave room fo r improvemen t s and f ee l t he HLA sys t em has a l o t o f po t en t i a l . "

As fo r t he fu tu r e , Fo rd , Ea ton , and t he U .S . Env i ronmen ta l P ro t ec t i on Agency (EPA) a r e j o in t l y conduc t i ng r e sea r ch on hyd rau l i c hyb r id veh i c l e s , i nc lud ing i n t e rna l combus t i on eng ine s t ha t wou ld p roduce hyd rau l i c p r e s su re t o d r i ve t he veh i c l e . Ea ton s i gned bo th a t e chno logy l i c ense ag reemen t and a coope ra t i ve r e sea r ch and deve lopmen t ag reemen t w i th t he EPA fo r t he deve lopmen t o f f u tu r e gene ra t i on sy s t ems .

Iner t ia , Force and MassEve ry th ing ha s i ne r t i a ; i f i t h a s a mass , i t h a s i ne r t i a . A hyb r id r e c l a ims ene rgy t h rough t he fundamen ta l s o f phys i c s . Do you r emember any h igh s choo l o r co l l ege phys i c s?

You app ly a fo r ce t o move an ob j ec t . The equa t i on fo r t h i s i s :

F=ma“F” be ing t he fo r ce , “m” be ing t he mass and

“a” be ing t he acce l e r a t i on

The f a s t e r you wan t an ob j ec t t o a cce l e r a t e , t he more fo r ce you have t o app ly .

Le t ’ s j u s t l ook a t t he e l e c t r i c mo to r fo r now. Ene rgy f rom the ba t t e ry (Wa t t s ) i s app l i ed t o t he co i l w ind ings i n t he mo to r . These w ind ings t hen p roduce a magne t i c f o r ce on t he ro to r o f t he mo to r , wh i ch p roduces t o rque on t he ou tpu t sha f t . Th i s t o rque i s t hen app l i ed t o t he whee l s o f t he c a r v i a a coup l i ng o f gea r s and sha f t s . When t he whee l t u rn s , i t app l i e s a f o r ce t o t he g round , wh ich due t o f r i c t i on be tween t he whee l and t he g round cause s t he veh i c l e t o move a long t he su r f ace . Th i s i s l i ke i f you we re i n a boa t a t a dock , and you g r abbed t he dock and pushed w i th you r a rm . The fo r ce you a r e gene ra t i ng i s mov ing t he boa t r e l a t i ve t o t he l oca t i on o f t he dock . The more fo r ce you app ly , t he f a s t you ge t t he boa t t o move .

Fr ic t i on in Hybr idsThe re i s f r i c t i on eve rywhe re i n t he hyb r id sy s t em. The re i s e l e c t r i c a l f r i c t i on be tween t he a toms and e l ec t rons mov ing i n t he w i r e s be tween t he ba t t e ry and t he mo to r and t h rough t he mo to r i t s e l f . The re i s magne t i c f r i c t i on i n t he me t a l l amina t i ons t ha t make up t he magne t i c c i r cu i t o f t he mo to r , a s we l l a s i n t he magne t s aga in on t he a tomic l eve l . Then , t he r e i s mechan i ca l f r i c t i on be tween eve ry mov ing pa r t , such a s t he bea r i ngs , s ea l s , gea r s , cha in s and so on . The by -p roduc t o f

f r i c t i on i s hea t . Take you r hands rub t hem toge the r and you r pa lms ge t wa rm. The f a s t e r you do i t , t he f a s t e r t hey hea t up . A l so , t he ha rde r t hey a r e p r e s sed t oge the r , t he f a s t e r t hey w i l l hea t . F r i c t i on i s ene rgy l o s t t o hea t . When a l l o f t he se l o s se s a r e added up , t ha t i s wha t de t e rmines t he e f f i c i ency o f t he veh i c l e .

Fr ic t i ona l Losse s in Convent iona l CarsA s t anda rd ca r gene ra t e s t o rque t o move t he whee l s t o d r i ve t he veh i c l e down the road . Dur ing t h i s t ime , i t i s gene ra t i ng f r i c t i on and l o s se s . When you app ly s t anda rd b r akes , i t i s j u s t ano the r f r i c t i on dev i ce t ha t ha s spec i a l l y de s igned ma te r i a l t o hand l e t he hea t f r om f r i c t i on , wh ich i s app l i ed t o t he d rums and ro to r s t ha t s t op t he whee l f rom tu rn ing . The f r i c t i on be tween t he whee l and t he g round s t ops t he veh i c l e . Th i s s t anda rd veh i c l e ha s f r i c t i ona l l o s se s t o move t he veh i c l e—and use s t he fundamen ta l beh ind f r i c t i ona l l o s se s t o s t op t he veh i c l e . So i t ’ s a l o se -l o se s i t ua t i on .

Trans ferr ing Torque Back to the MotorThi s i ne r t i a i s t he fundamen ta l p rope r ty o f phys i c s t ha t i s u sed t o r e c l a im ene rgy f rom the veh i c l e . I n s t e ad o f u s ing 100% o f t he founda t i on b r akes o f t he veh i c l e , wh i ch a r e t he f r i c t i on b r akes , we now l e t t he l i nkages back t o t he mo to r such a s t he d r i ve sha f t s , cha in s , and gea r s t r ans f e r t he t o rque f rom the whee l s back i n to t he mo to r sha f t . One o f t he un ique t h ings abou t mos t e l e c t r i c mo to r s i s t ha t e l e c t r i c a l ene rgy can be t r ans f e r r ed i n to mechan i ca l ene rgy and a l so mechan i ca l ene rgy can be t r ans f e r r ed back i n to e l e c t r i c a l ene rgy . I n bo th ca se s , t h i s c an be done ve ry e f f i c i en t l y .

Thus , t h rough t he t e chno logy o f t he mo to r and mo to r con t ro l l e r , t he fo r ce a t t he whee l s becomes t o rque on t he e l e c t r i c mo to r sha f t . The magne t s on t he sha f t o f t he mo to r ( c a l l ed t he ro to r—the mov ing pa r t o f t he mo to r ) move pa s t t he e l e c t r i c co i l s on t he s t a t o r ( t he s t a t i ona ry pa r t o f t he mo to r ) pa s s ing t he magne t i c f i e l d s o f t he magne t s t h rough t he co i l s p roduc ing e l ec t r i c i t y . Th i s e l e c t r i c i t y becomes e l ec t r i c a l ene rgy , wh ich i s pumped back t o t he ba t t e ry . Th i s , i n t u rn , cha rge s t he hyb r id ba t t e ry pack . Th i s i s whe re t he commen t “ r egene ra t i on” o r “ r ec l a iming ene rgy” comes f rom.

Tha t i s t he ba s i c s o f how r egene ra t i on works . How much ene rgy you can r ec l a im depends on a l o t o f f a c to r s . The re a r e d i f f e r en t r egene ra t i on t heo r i e s and de s igns , wh ich f a l l i n t o two g roups : one be ing ca l l ed pa r a l l e l r egen and t he o the r c a l l ed s e r i e s r egen , wh ich a r e d i f f e r en t f r om the pa r a l l e l and s e r i e s hyb r id s . These r egen g roups s t r i c t l y a r e de s ign t opo log i e s fo r b r ak ing sy s t ems . I t a l so ma t t e r s how many whee l s you a r e u s ing t o r e c l a im ene rgy . Mos t veh i c l e s t o da t e a r e f ron t whee l d r i ve so you can on ly r ec l a im ene rgy f rom the f ron t

whee l s . The back whee l s s t i l l was t e ene rgy t o s t anda rd f r i c t i on b r akes un l e s s t hey a r e somehow connec t ed back t o t he e l e c t r i c mo to r . The o the r f a c to r i s ba t t e ry s t a t e o f cha rge and how ha rd can you d r i ve t ha t ene rgy back i n to t he ba t t e ry .

CHAPTER 7: CONCLUSION

Theore t i c a l i nves t i ga t i ons o f a r egene ra t i ve b r ak ing sy s t em show abou t

25% sav ing i n fue l consumpt ion .

The l ower ope ra t i ng and env i ronmen t cos t s o f a veh i c l e w i th

r egene ra t i ve b r ak ing sy s t em shou ld make i t more a t t r a c t i ve t han a

conven t i ona l one . The t r ad i t i ona l co s t o f t he sy s t em cou ld be

r e cove red i n t he f ew yea r s on ly .

The exhaus t emi s s ion o f veh i c l e u s ing t he r egene ra t i ve b r ak ing concep t

wou ld be much l e s s t han equ iva l en t conven t i ona l veh i c l e s a s l e s s f ue l

a r e u sed fo r consumpt ion .

These sy s t ems a r e pa r t i cu l a r l y su i t ab l e i n deve lop ing coun t r i e s such a s

Ind i a whe re buse s a r e t he p r e f e r r ed means o f t r anspo r t a t i on w i th in t he

c i t i e s .

BIBLIOGRAPHY

1) Genera l Motors Webs i t e ( www.gm.com ) .

2 ) www.sae .org

3 ) www.goog l e . com