Study on Clutch Control Technology and Shift Control Strategy for Automated Mechanical Transmission with Magnetic Powder Clutch

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1 tudy on Clutch Control Tchnology and hift Control tratgy for Automatd chanical Transmission with agntic Powdr Clutch XU HANZHEN, WANG CHENG Faculty of Transportation Enginring Huaiyin Institut of Tchnology 1 East ichng Road, Huai'an, 3003, Jiangsu, P. R. China CHINA kqing6657@16.com Abstract:- inc thr is mor spac for th shift quality and transmission fficincy of convntional automatd mchanical transmission (AT) to improv, a novl lctric AT with magntic powdr clutch (AT) was proposd and studid in this projct. Th major tchnological problms of AT about control tchnology for magntic powdr clutch and comprhnsiv shift ruls wr studid basd on thortical analysis and simulation rsarch. Th fuzzy controllr was dsignd, which ralizd th intllignt control for th ngagmnt and disngagmnt of magntic powdr clutch whn th vhicl starts and shifts. Th comprhnsiv shift ruls wr cratd basd on fuzzy rasoning and wight mthod. Th simulation modl for th whol vhicl was built and th off-lin simulation was carrid out. Th simulation rsults obtaind by 15-condition mthod showd that th built simulation modl for th whol vhicl was corrct. Th simulation rsults of continuous upshift with 80% throttl opning showd that th control modl for th magntic powdr clutch was rasonabl and th shift quality was improvd. Th simulation rsults for fundamntal shift ruls and comprhnsiv shift ruls with th spcific vhicl spd and th throttl opning showd that th comprhnsiv shift ruls cratd in this papr can rduc th shifting frquncy and improvd th shifting quality. Ky-words:- magntic powdr clutch, AT, fuzzy control, comprhnsiv shift ruls, simulation 1 Introduction Dvloping small passngr cars and conomy cars and rducing nrgy consumption of th car ar th currnt trnds for th auto industry. Transmission tchnology is on of th cor tchnologis to improv th ful conomy and th comfort of th vhicl and so on, and its dvloping dirction is th automatic transmission. Clutch control is always th cor and th difficulty in th study of automatic transmission control. Th friction clutch and hydraulic torqu convrtr ar th currnt commonly usd clutchs for th vhicl. Friction clutch is widly usd in manual mchanical transmission. Whil in th automatic transmission, it is complx to control for it nd th additional srvo mchanism to control clutch. Hydraulic torqu convrtr has problms of complx structur, high cost, low transmission fficincy and so on, so it is not suitabl for mini cars [1]. Th magntic powdr clutch for th vhicl is a nw typ powr transmission mmbr. It has th advantags of smooth ngagmnt, asy to control, torqu transmission wid rang and has nothing to do with th slip, fast rspons and so on. And it adaptd to th working charactristics of vhicl drivlin, which nsur th vhicl to oprat with high fficincy and smooth opration []. A magntic clutch was prviously proposd in litraturs of [3-4], which can ffctivly achiv rapid and rliabl sparation and ngagmnt, obtain optimal slip torqu and improv ngin lif. Th ways and mthods to improv th magntic clutch prformanc wr studid for th low torqu transmission capacity of th magntic powdr clutch for domstic cars [5-8]. inc thr is mor spac for th shift quality and transmission fficincy of convntional automatd mchanical transmission (AT) to improv, a novl lctric AT with magntic powdr clutch (AT) was studid in this projct. Th major tchnological problm of th novl AT about control tchnology for magntic powdr clutch and comprhnsiv shift ruls will b studid basd on thortical analysis and simulation rsarch. Dynamic modl for th transmission systm of th whol vhicl.1 tatic charactristics of th magntic powdr clutch Th charactristic curv of th magntic powdr clutch was shown in Fig.1 [5]. Th corrsponding rlationship E-IN: Volum 9, 014

2 btwn xciting currnt and xciting currnt dnsity was listd in tabl 1. caus th working currnt was highr most of th tim and th small currnt lasts a vry short tim, th lin with small currnt may b nglctd and was fittd with a straight lin. Th fitting quation was as follows: Tc = 113i 7 ( i 0.35A) (1) whr T c is th transmission torqu of th magntic powdr clutch in N.m and i is th xciting currnt in A(mprs). Considring th starting charactristics of th magntic powdr clutch has transint rspons dlay, and its small working currnt lasts a vry short tim, th torqu is thought to b zro if i < 0.35A. Fig.1. tatic charactristics of th magntic powdr clutch Tabl 1 Corrsponding rlationship btwn th xciting currnt and xciting currnt dnsity xciting currnt dnsity /(A/mm ) xciting currnt /A Dynamic quation of th magntic powdr clutch Dynamics quation for th drivn part of magntic powdr clutch whn th vhicl starts is xprssd as follows [9] : dωc Tr Jc Tc = i i η () g 0 whr J c is th quivalnt momnt of inrtia of th clutch drivn part, ω c th angular vlocity of th clutch drivn part, T c th torqu transmittd by th clutch, T r th rsistanc torqu of th vhicl, η th mchanical fficincy of th transmission systm, i g th spd ratio whn th vhicl starting, i 0 th spd ratio of th main rducr. Dynamics quation for th activ part of clutch is writtn as follows: dω J = T Tc (3) whr ω is th angular vlocity of th ngin, T is th output torqu from ngin, and J is th ngin output shaft rotation inrtia. Thr ar two valuation indxs for vhicl starting, i.. impact and friction work. Th impact, j, is xprssd as follows: da d v j = = (4) whr a is th longitudinal acclration of th vhicl and v is th spd of th vhicl. Th output torqu from th drivn part of th magntic powdr clutch is a function of xcitation currnt, which can b xprssd as quation (1). An approximatly linar rlation btwn th output torqu and th xciting currnt is obsrvd. asd on () and (4), th following can b obtaind as: dv r dtc j = = (5) Jcigi0 whr r is th working radius of th driving whl. According to quations of (), (3) and (4), whn th vhicl starting, th spd of th clutch driv part dcrass, th spd of drivn part riss and thy ultimatly achiv synchronization. Th synchronization tim dpnds on th output torqu of magntic powdr clutch. Th impact dpnds on th xcitation currnt chang rat of magntic powdr clutch in synchronous tim. Th friction work for vhicl starting procss, L, is xprssd as follows: t1 t L = T ω + T ω ω 0 ( ) c c t c c 1 (6) whr t 1 is th tim that th output torqu of clutch riss from zro to th rsistanc momnt, t th tim that th drivn part of clutch bgins to rotat until its spd quals to that of th drivn part. E-IN: Volum 9, 014

3 Th working stat of th magntic powdr clutch is composd of locking stat and non-locking stat [10]. (a) locking stat: ω = ω T c out c out = T c in c in (7) Jc out = Jc in + Jc whr ω is th input spd of th modl, namly, c in ω th spd of th input shaft in rad/s; c out is th output spd of th modl, that is, th spd of th output shaft in rad/s; T is th input torqu of th magntic c in powdr clutch in N.m; Tc out is th output torqu of th magntic powdr clutch modl in N.m and it is passd dirctly to th transmission modl; Jc in is th momnt of inrtia of th clutch modl in kg.m ; Jc out is th output momnt of inrtia of th magntic powdr clutch modl in kg.m ; Jc is th momnt of inrtia of th magntic powdr clutch in kg.m. (b) Non-locking stat: Tc in Tc out ωc in = + k J c in ( T T ) Tc out = min c, c in (8) Jc out = Cc Jc in + Jc whr k is th intgral initial valus; C c is th control instruction of th magntic powdr clutch and its valu is calculatd by th control stratgy modul. C c rprsnts th working stat of magntic powdr clutch and its valus rang is [0, 1]. 0 mans compltly sparation, 1 mans locking stat, and valus btwn 0 and 1 mans th joint dgr of magntic powdr clutch in a slip stat..3 Engin modl Th powr prformanc and ful conomy of vhicl mainly dpnd on th srvic prformanc of th ngin. Th bst shift schdul can b mappd out by fitting srvic prformanc curv and building its mathmatical modl. Th working procss of th ngin is complx, its mathmatical modl rlats to a larg numbr of diffrntial quations, so it is not fasibl to dscrib it with simpl mathmatic formulas. Th most commonly usd mthod of building mathmatical modl is to construct th rlationship btwn th output torqu and th throttl opning as wll as th ngin spd by using th charactristics tst datum of th ngin in a stady stat. According to th ngin prformanc tst mthod, th ngin bnch tst can b don to acquir th tst datum. Four polynomial mthods may b usd to fit th torqu charactristics of th ngin and construct th numrical modl of th rlationship btwn ngin torqu T and th throttl opning α as wll as th ngin spd n. Four polynomial xprssion about th torqu, th throttl opning and th ngin spd is shown as following: 4 3 T = an 1 + an + an 3 + an 4 (9) b1α + bα + b3α + b4α + c whr a i, bi and c ar th fitting cofficints. Th output torqu can b obtaind basd on th ngin spd and th throttl opning. Th rlationship btwn th ngin powr and th spcific ful consumption with diffrnt ngin spd can b obtaind according to th ngin load charactristic. Th ngin load charactristic curv was shown in Fig.. Fig.. Engin load charactristic curv.4 Transmission modl Transmission is mainly usd to chang th spd ratio to adjust th output spd and th torqu of th ngin. Th charactristic quations ar shown as follows: Tout =ηtit g in (10) nin = in g out whr nin and n out ar th input spd and th output spd of th transmission rspctivly; T in and T out ar th input torqu and th output torqu of th transmission rspctivly; i g is th transmission ratio; η T is th transmission fficincy. Th main tchnical paramtrs of th transmission ar shown in tabl. Tabl ain tchnical paramtrs Paramtr Valu E-IN: Volum 9, 014

4 maximum input torqu maximum spd cntr distanc spd ratio of shift 115 N.m 6000 r/min 7mm Vhicl dynamic modul Th longitudinal dynamic modl of th vhicl was built to calculat th longitudinal acclration, vlocity and displacmnt basd on vhicl driving forc and driving rsistanc forc [11]. Th driving rsistanc forc is composd of rolling rsistanc forc, air rsistanc forc, climbing rsistanc forc and so on..5.1 Driving forc of vhicl Driving forc of vhicl is xprssd as following: T Ti td gi0η Ft = = (11) r r whr T td is th driving torqu that works on th driving whl, r th rolling radius of th whl, η th mchanical fficincy of th transmission systm, ig th transmission ratio, i 0 th main rducr transmission ratio..5. Vhicl driving rsistanc forc Th vhicl longitudinal rsistanc forc includs rolling rsistanc forc F f,air rsistanc forc F w, acclration rsistanc forc F j and climbing rsistanc forc F i. Its xprssion is shown as blow: F = F f + F F F w + j + i (1) Ff is rlatd to th tir load, th typ and th pavmnt condition. Its xprssion is shown as blow: Ff = Gf cosθ (13) whr G is th total wight of th vhicl in N, f th rolling rsistanc cofficint, and θ th ramp angl rspctivly. Fw is xprssd as blow: CAv d ρ Fw = (14) whr C d is th air rsistanc cofficint; A is th automotiv frontal ara in m ; ρ is th air dnsity 3 in kg/m and v is th running spd of th vhicl in m/s. Fj is xprssd as blow: dv Fj = δ m (15) whr δ is th vhicl rotary mass cofficint and m is th vhicl quality in kg. F i is xprssd as blow: Fi = Gsinθ (16) Th vhicl acclration of a is shown as blow: dv Ft Fi Ff Fw a = = (17) δ m vhicl spd is xprssd as blow: t v = a (18) 0 3 hift ruls Th shift rul is usd to rmin th shifting tim of vhicls, and it can rflct drivrs' handling intntion and fit diffrnt running nvironmnt. Th shift rul dirctly influncs th dynamic prformanc, conomic prformanc and mission prformanc of th vhicl. 3.1 Fundamntal shift ruls Vhicls oprat with diffrnt stat paramtrs, and th optimal shift schdul of vhicls is rmind according to crtain principls of prformanc paramtrs optimal. any vhicls slct bst shift timing whn th vhicl oprats on th bst powr or conomy prformanc. Th following will pay mor attntion to introduc th procss of stablishing optimal powr prformanc shift schdul. To nsur optimum dynamic prformanc of vhicls, th intrsction of two adjacnt gar acclrations should b slctd as th bst dynamic shift points in a dynamic opration condition. Th intrsctions of two adjacnt gar acclrations with diffrnt throttl opning wr connctd and form a curv, and th curv is just th optimal dynamic shifting charactristics. If it was convrtd to its corrsponding α v curv, w will gt th bst dynamic up-shifting schdul. asd on th dynamic shifting schdul and vhicl dynamic driving quations, th following quations can b obtaind as: dvn, α dv n N+ 1, αn = (19) dvn, α g n = Ft( N, αn ) Fw Fi F f δ NG (0) g Jw gj ( + λ) δn= 1+ + ii 0 gn, η (1) Gr Gr E-IN: Volum 9, 014

5 whr vn, α and v n N + 1, α ar th vhicl spd of th Nth n gar and N+1th gar rspctivly whn th throttl opning is α n ; δ N is th rotary mass cofficints of Nth gar affctd by th ngin charactristics; Ft( N, α ) is th vhicl driving forc of th i gar; J and J w ar th inrtia which connctd to th ngin flywhl and th rotational inrtia of th whl rspctivly; λ is th dcrasing cofficint of th ngin in a unstady stat ngin, and i, is th transmission ratio of th g N Nth gar. Th optimal dynamic up-shifting curv can b obtaind by solving abov quations. Th solvd curv is as shown in Fig.3. In th practical application, it should b considrd that a slight spd dclin causd by th powr intrruption for shifting. Th rat of dclin diffrs with th vhicl spd. n Fig.4. Influnc of various factors on shift ruls for drivr charactristics Fig.5 is th diagram for fuzzy rasoning about driving string bhavior charactristic. Th rcognition for driving string bhavior charactristic is a fuzzy rasoning procss. According to paramtrs of throttl opning, throttl opning chang rat and vhicl acclration, th driving string bhavior charactristic is xprssd by a quantifiabl paramtr through fuzzy rasoning. This quantifiabl paramtr is usd to rmin what typ th drivr is and thn rvis th fundamntal shift rul, thrby gtting th idal control ffct. Throttl opning Fig.3. Optimal dynamic up-shifting curv Th drop point is slctd and calculatd basd on its rgular up-shifting schdul and slction of convrgnc dgr, and 5km/h is slctd in this papr. And at th sam tim, down-shifting spd of th N gar must b qual to or gratr than th minimum spd of th N gar to prvnt ngin to misfir. 3. Comprhnsiv shift ruls Th outlind abov about th fundamntal shift ruls is basd on dynamic principl, which considr mor about optimal prformanc ara in a stady stat for th ngin and can not mt th rquirmnt for driving. In this papr, th rvisd shift ruls ar formulatd which also considr th dynamic prformanc in a dynamic oprating condition and various influncing factors about human-vhicl-road [1]. Th influnc of various factors on th shift ruls is as shown in Fig.4. Throttl opning chang rat Acclration Fuzyy procss Fuzzy infrnc Prcision procss Drivr typ Fig.5. Diagram for fuzzy rasoning about driving string bhavior charactristic Th shift rul for th running condition mod is rmind by adopting wight corrction mthod. Conditions mting ach shift mod ar dsignd firstly according to th masurd paramtrs by snsors, and thn th wights of shift tabl for diffrnt mods ar rmind. Th wight with high priority is first slctd as long as it satisfid th shift condition. Thr ar thr influnc factors for th dsign of th wight. Thy ar shift procss risk lvl, shift intnsity and vhicl prformanc influnc factor. Th influnc of ach factor is valuatd and its wight is rmind. o th shift priority is thn calculatd and th rasonabl shift ruls ar obtaind. Th calculation of th shift priority is basd on th xprssion of (). Q = ϕ ψ () ϕ (1 ~ 10), ψ (0 ~ 1) E-IN: Volum 9, 014

6 whr φ is th shift influnc intnsity, ψ is th influnc factor wight, and Q is th shift priority dgr. Th shift rul can b rmind according to th slction logic for shift mod. Parts of th shift mod priority and thir calculation ar showd in tabl 3. shift mod Tabl 3 hift mod priority dangr intnsity influnc factor shift intnsity φ ψ φ ψ φ ψ Q priority dgr thrmal mod curv mod uphill mod dynamic mod conomic mod asd on th dsign mthod for shift ruls, th shift ruls for various mods can b workd out according to th whol vhicl paramtrs. Th shift ruls for uphill mod ar as shown in Fig.6. Fig.6 hift ruls for uphill mod 4 Fuzzy control tchnology of th magntic powdr clutch caus of various driving conditions, drivr's intntion is not always constant.whil th proportional control stratgy cannot b satisfid with th starting rquirmnt undr various conditions, and fuzzy control algorithm was widly applid to th start and shift control of magntic powdr clutch for it can adaptd to complx conditions. 4.1 tarting fuzzy controllr for magntic powdr clutch Th starting control stratgy for magntic powdr clutch is to raliz two goals [9] : Th first goal is to nsur that th ngin oprats stably. It nds to rmin th initial xcitation currnt of magntic powdr clutch, which rmins th initial output torqu for th ngagmnt of magntic powdr clutch. If th torqu is lowr than th ngin load, it is asy to caus too fast ris of th ngin spd and too larg of spd diffrnc, which is not conduciv to clutch synchronous. ut if th torqu is largr than th ngin load, it is asy to caus th ngin spd too low and vn misfir. Thrfor, th initial xcitation currnt should b rmind according to throttl opning signal and ngin spd signal. caus th ngin spd may rflct th ngin load and influnc th sliding friction work, th spd is takn as th primary control paramtr for th ngagmnt control. Th scond goal is nsur th rid comfort of clutch ngagmnt. To achiv this goal, th growth rat of th xcitation currnt of magntic powdr clutch should b controlld bfor it rachs th ratd currnt. Thrfor th xcitation currnt growth rat should b rmind basd on throttl opning signal and spd diffrnc signal ( n ) of driving and drivn parts of magntic powdr clutch. If th throttl opning is small, th growth rat of xcitation currnt may b lss and th vhicl starts smoothly. Whn n rachs th maximum valu, th ngagmnt impact may b th largst. o at this tim, th xcitation currnt growth rat should b dcrasd. Along with th rduction of n, th xcitation currnt growth rat will ris. Whn n rducs to zro, th xcitation currnt growth rat may ris to th maximum with no impact. Th starting fuzzy controllr for magntic powdr clutch includs initial xcitation currnt fuzzy controllr, and xcitation currnt growth rat fuzzy controllr. Th input variabls of initial xcitation currnt fuzzy controllr ar th throttl opning α and th ngin spd n, and th output variabl is th initial xcitation currnt I. Th input variabls of th xciting currnt growth rat fuzzy controllr ar throttl opning α, th spd diffrnc n of clutch driv part and drivn part, and th output variabl is xcitation currnt growth rat I. Th input variabls of α, n and n ar th 7-grad fuzzy st, and thir fuzzy substs for α, n and n may b xprssd as α = n = n={,, L,,,, }. Th output variabls of I and ar also th 7-grad fuzzy st, and E-IN: Volum 9, 014

7 thir fuzzy subst for I and may b xprssd as I = I = {,, L,,,, }. Th usd fuzzy languag control ruls is if-thn algorithm. Th fuzzy rasoning ruls for th initial xcitation currnt ar as shown in tabl 4, and th fuzzy rasoning ruls for xcitation currnt growth rats ar as shown in tabl 5. Tabl 4 Fuzzy rasoning ruls for initial xcitation currnt L L α n I L L L L Tabl 5 Fuzzy rasoning ruls for xcitation currnt growth rat α Δn Í L L 4. hift procss control for magntic powdr clutch paration and ngagmnt of magntic powdr clutch ar includd in shifting procss. In th shifting procss, th vhicl's powr prformanc will suffr du to th sparation and ngagmnt of magntic powdr clutch. If th powr intrruption tim is too long, th acclration prformanc and rid comfort in low gar of vhicl will b affctd. In addition, th automatic control prformanc of magntic powdr clutch is important for shifting schdul action in th shifting procss. Th opration of magntic powdr clutch must b coordinatd with shifting action, which rlats to th ral-tim and accuracy for th shift procss and is a crucial part for th shifting rsarch. Th sparation control of magntic powdr clutch is simpl in th shifting procss. Whn it nd shift, th magntic powdr clutch would b cut off th powr and th control currnt quickly droppd to zro.th sparation should b swift and swping so that cut off th powr transmission quickly. Th ngagmnt control of th shifting is similar to that of starting of magntic powdr clutch. Th spd of diffrnt drivn parts dos not incras gradually from zro to th maximum. Thrfor, th gar ngagmnt control stratgy is consistnt with that of th starting. In th shifting procss, th xciting currnt and its chang rat of magntic powdr clutch ar also controlld according to th paramtrs of throttl opning α, ngin spd n and spd diffrnc n btwn driv part and drivn on of clutch. 5 Vhicl prformanc simulation In ordr to vrify th comprhnsiv shift ruls for AT and th fuzzy controllr for th magntic powdr clutch, th modl of whol vhicl with AT was st up. Th modl was simplifid on th prmis of no influnc on vhicl function. Th simplifid simulation systm includs th following moduls: th powr transmission systm modul ( including ngin, magntic powdr clutch and transmission), th vhicl dynamics modul, th bst shift schdul modul, th magntic powdr clutch E-IN: Volum 9, 014

8 control modul, driving condition modul and drivr modul. 5.1 Driving condition modul Th slctd running conditions for th prformanc simulation of whol vhicl ar 15-condition, acclration condition with throttl opning of 80% and a crtain random condition. Th 15-condition mthod includs four cycls, and th 15-condition curv is as shown in Fig.7. Each tst cycl includs 15 diffrnt loads and spd such as idl, acclration, constant spd, dclration, tc. Th changs of vhicl spd and throttl opning undr a spcific random condition ar shown in Fig.8. Fig condition curv Fig.8 Changs of vhicl spd and throttl opning undr a spcific random condition 5. Drivr modul Th drivr modul includ throttl controllr modul and brak controllr modul [11]. In this papr, PID controllr is dsignd to control throttl. Th throttl controllr can b xprssd as follows: α = kp 1( vt v) + ki1 ( vt v) (3) 0 α αmax whr α max is th maximum opning of th throttl; v t is th targt spd; v is th actual spd; k p1 is th throttl controllr proportional cofficint; ki1 is th throttl controllr intgral cofficint. Th brak controllr is xprssd as follows: d( vt v) Fµ = kp( vt v) + ki ( vt v) + kd (4) 0 Fµ Fµ max whr F µ is th braking forc; k p is th brak controllr proportional cofficint; k i is th brak controllr intgral cofficint; k d is th brak controllr diffrntial cofficint; F µ max is th maximum braking forc. om domstic conomy cars was takn as th rsarch objct in this papr, th main prformanc paramtrs wr as shown in tabl 6. Th stablishd modl of th vhicl using atlab/imulink is shown in Fig.9. Paramtr Tabl 6 ain paramtrs of th vhicl Valu Total vhicl mass /kg 1050 Frontal ara /m 1.9 Air rsistanc cofficint 0.30 Tir rolling radius /m 0.9 Rolling rsistanc cofficint ain rduction gar ratio 3.94 Engin displacmnt /L 1. aximum ngin torqu /N.m 115 omnt of inrtia of th ngin /kg.m 0.0 omnt of inrtia of th clutch /kg.m Transmission input shaft nd of ach gar inrtia /kg.m 1] ] ] E-IN: Volum 9, 014

9 4] ] ] 0.54 ] 0.4 Each gar transmission output shaft rotational 3] 0.16 inrtia /kgm 4] ] 0.11 omnt of inrtia of th whl /kg.m 15 Fig.10. imulation curv of th vhicl with AT undr a 15-condition Th continuous upshift simulation curv of vhicl with AT with a throttl opning 80% is shown in Fig.11. Th simulation rsults showd that it taks 14 sconds for th vhicl to acclrat to 100km/h, which agrs with th actual situation. Th shift impact dgr curv showd that th impact dgr is maximal whn magntic powdr clutch rlass, th impact dgr is minimal whn magntic powdr clutch ngags, th absolut valu of impact dgr is lss than its maximum allowabl valu of 10m/s -3, and that th shift quality is improvd. Th impact dgr curv also indicats that th impact dgr whn clutch rlass incrass with th incras of spd, which is bcaus th driving rsistanc and dclration of th vhicl incras with th incras of th spd. Th ngagmnt impact dgr of th magntic powdr clutch is maximal whn th vhicl with AT starts, which is bcaus th spd diffrnc btwn th driv part and drivn part of th magntic powdr clutch is grat undr th starting condition. Fig.9. Establishd modl of th vhicl using atlab/imulink 5.3 imulation rsults and analysis Th vhicl spd curv and gar shift curv of vhicl with AT undr a 15-condition ar givn in Fig.10. y comparison, it is found that th simulation spd is basically in agrmnt with th thory rsults. From th gar shifting curvs, w can s that whn th AT shifting from nutral gar to a nw gar, thr is transint zro momnt in th shifting procss curv, which conforms to th shifting spcification. Fig.11. Continuous upshift simulation curv of vhicl with AT with a throttl opning 80% Th starting charactristics simulation curv of magntic powdr clutch undr th starting condition with a throttl opning 80% was as shown in Fig.1. Th simulation showd that th synchronization tim of clutch is 1.3s, which is consistnt with drivrs' intnt that th vhicl starts quickly whn th throttl opning is larg. And th compact dgr undr this condition can b controlld in th allowabl rang. E-IN: Volum 9, 014

10 traditional AT. Th fuzzy controllr for vhicl starting and th fuzzy controllr for ngagmnt control of magntic powdr clutch whn vhicl shifting wr dsignd in this papr. And th intllignt control of magntic powdr clutch was ralizd whn vhicl starting, shifting and parking. Th factors influncing th shift ruls wr analyzd. Th comprhnsiv shift ruls wr formulatd basd on th fundamntal shift ruls. Th simulation modl of th whol vhicl with AT was built and simulatd off-lin. Th simulation rsults showd that th intllignt control modl of th magntic powdr clutch was accuracy and th comprhnsiv shift ruls was ffctiv. Fig.1. tarting charactristics simulation curv of magntic powdr clutch Th simulation curvs of fundamntal shift ruls and comprhnsiv shift ruls undr th sam condition wr shown in Fig.13. Th rsults showd that using th comprhnsiv ruls can rduc shift frquncy and unncssary shift. Fig Conclusions In this papr, a nw typ AT systm with magntic powdr clutch (AT) was studid basd on Acknowldgmnts: This work was supportd by Jiangsu Provincial Univrsity Natural cinc Rsarch Projct of China (No. 1KJD580001). Rfrncs [1] Wi Yingjun, Chang iqin, Hu Pin. Dsign and control of vhicl magntic particl clutch, [J] chanical nginring, v4, No.10, 004, pp In Chins [] Watanab, Tomoyuki. Apparatus for controlling a magntic particl clutch for us in a vhicl. Unitd tats Patnt, , [3] Toshio Ttakano. ELECTRO-AGNETIC POWDER CLUTCH YTE FOR AUTOOILE. Unitd stats patnt, , 1980 [4] Wang hu. A controllabl vhicl magntic particl clutch. China patnt, CN , 003 [5] Wang Chng, Chang iqin. tructur and Prformanc Analysis of Vhicl agntic Particl Clutch. [J] Journal of Nanjing Univrsity of cinc and Tchnology, v36, No.5, 01, pp In Chins. [6] Wang Chng, Chang iqin. tudy on Effcts of agntic Particl Proprtis on Prformanc of agntic Particl Clutch. [J] China chanical Enginring, v 3, No., 01, pp In Chins. [7] Wang Chng, Chang iqin. Analysis and Dsign on Torqu Prformanc of agntic Particl Clutch. [J] Transactions of th Chins ocity for Agricultural achinry, v4, No.10, 011, pp.35-38,34. In Chins. E-IN: Volum 9, 014

11 [8] Wang Chng, Chang iqin. Thrmal Analysis and Tst Raarch of thagntic Powdr Clutch for Vhicls. [J] WEA TRANACTION ON APPLIED AND THEORETICAL ECHANIC, v9, 014, pp [9] Wi Yingjun, Chang iqin. Rsarch on Fuzzy Control Tchnology Applid to agntic Powdr Clutch during Vhicl tarting.[j] China chanical Enginring, v16, No.11, 005, pp In Chins [10] Yan Yun-bing, Zhou Jian-png, Chn Huaming. Fuzzy Control and miulation for Transmission Procss of agntic Powdr Clutch during hifting.[j] Tractor&Farm Transportr, v37, No.3, 010, pp In Chins [11] Chang iqin. Vhicl Powr Equipmnt, China achin Prss, 006. [1] Li Yong, Chang iqin, Wi Yingjun. hift tratgy of AT Vhicl asd on pd and Torqu Control. [J] China chanical Enginring, v, No.15, 011, pp In Chins. E-IN: Volum 9, 014