Cac ket qua tren cho thiy, vifc phat trien md hinh tuong tac ldp dudng ca ban cua Pacejka bang each them vao mpt sd hf so de xem xet anh hudng ciia gdc nghieng ngoai y va sy bien thien [r]
Trang 1NGHIEN CUfU-TRAO Ddi
VANH Hl/dNG CUA CAC THONG S6 DONG LU'C HOC
TRONG TU'ONG T A C L 6 P V A O U ' O N G
EFFECTS OF DYNAMICS AND STRUCTURE PARAMETERS
TO THE TIRE FORCES
KS Ha Van Tuan', TS.Vii Ngpc Tuin^
^Trudng Dai hpc Phdng chay Chira chay
^ Hgc vifn Ky thuat Quan sy
T O M T A T
Bdi bdo ndy gidi thieu mgt so ket qud nghiin euu chinh khi tien hdnh phdt triin mo hinh
Pacejka ca bdn ve tuang tdc lop/dudng Cdc gid tri phdn lire tgi vitng tuang tdc dugc xdc dmh bdng
phirangphdp md hinh hod vd mo phong khi cd tinh din dnh hudng cua tdi trgng thdng ddng vd cdc
goc ddt cua bdnh xe ddn hudng Kit qud nghiin ciru cho thdy khd ndng ung dung cua mo hinh duac
xdy dung trong viec tinh todn thiet ke cdc logi ldp mai cdng nhu gidi cdc bdi todn dgng Im: hgc d td
Tir khda: Md hinh hod; Md phdng; Tuang tdc lop/dudng
ABSTRACT
This paper presents some research results when the model of Pacejka was developed for tire/
road forces calculating The tire/road forces are determined in considering the effects of vertical
load and wheel inclinations by using modelling and simulation method The results show that our
tire/road developed model can be applied for tire design and determination of vehicle dynamics
aspect solution
Keywords: Modeling, Simulation, tire/road interaction ^
ISSN 0866 - 7056
TAP CHf CO KHf VIET NAM, Sd 11 nam 2015
Trang 21 DAT VAN DE
Ldp xe la phin tir kit ndi gifta xe va mat
dudng, nd cho phep truyin lyc tac dung tit mat
dudng len khung xe lam cho xe chuyen ddng
tinh tiln Khi nghien ciiu ddng luc hpc toan xe
ndi chung va ddng lyc hpc tuong tac Idp/dudng
ndi rieng, vifc md ta dgc trung cua be mat dudng
va dgc tinh ciia ldp rit khd khan De xac djnh cac
thanh phin lyc tai vung tuong tac gifta ldp va
dudng, tren thi gidi cd rit nhiSu cac md hinh md
ta tuong tac giua ldp va dudng dugc xay dyng
nhu Dugoff [2], Brush [6] Nhung trong cac
md hinh nay cac nha nghiSn ciiu da chap nhgn
nhftng gia thuylt nhim don gian hda md hinh
vi dy nhu: (i) Khdng xet den anh hudng cua cac
gdc dgt banh xe, (ii) Mat dudng ciing khdng bien
dang, dan din kit qua tinh toan cua mo hinh chi
ap dung trong mdt sd trudng hgp cu the Tai Vift
Nam, Cling cd mdt sd nghien ciiu ve tuang tac
gifta ldp va dudng nhu: (i) tTng dung md hinh
Idp dya tren nhftng nghiSn cmi ciia H Dugoff de
xay dyng md hbih ddng luc hpc quay vdng xe
d td quSn sy nhilu cau trong cac hf md phdng
[2], (ii) Tac gia Nguyen Trudng Sinh da xay
dyng dugc md hinh md phdng hf thdng truyen
lyc cua xe bpc thep nhieu cau BTR-60PB bang
phan mem Matlab-Simulink cimg vdi vifc sir
dyng khdi md hinh dan gian cua Pacejka de md
ta tuong tac ldp dudng [3] Hau het cac nghien
Cliu trong nude mdi chi dimg lgi d vifc ap dyng
cac md hinh ma chua di sau xay dyng md hinh
tuong tac ldp va dudng
Ndi dung chinh cua bai bao, trinh bay
mdt sd ket qua nghien ciru chinh khi tien hanh
phat trien md hinh ca ban cua Pacejka, nham
myc dich tinh den anh hudng ciia tai trpng thing
diing va cac goc dgt banh xe din hudng din gia
tri cua cac thanh phin lyc tai vimg tuang tac ldp/
dudng Ket qua nghien ciiu cua bai bao se cho
thay md hinh nang cao cd the dupc ap dyng khi
md rdng pham vi nghien ciiu vl dpng luc hgc d
td vi dy nhu: (i) Khao sat anh hudng cua ket cau
hf thdng treo den kha nang chuyen ddng cua 6
td, (ii) Ddnh gia tudi thp cua ldp khi cd su thay ddi cua cac gdc dat banh xe dan hudng
2 MO HINH TirOfNG T A C LOP VA DlTdNG
Tit ca cac md hinh md ta tuong tac ldp/ dudng, nhim myc dich xac dinh cac thanh phan luc tai vimg tiip xiic: (i) Luc dpc Fx , (ii) Luc ngang Fy (iii) va md men ty ddng dn dinh Mz (Hinh 1) Diu tien hai gdc chinh ma ta can xem
xet do la gdc nghieng j va gdc trugt ben a Gdc
nghieng y la gdc Ifch so vdi phuang thang diing ciia ldp xe do kit ciu cua hf thdng treo, gdc trugt ben a la gdc Ifch giiia 2 hudng chuyen ddng cua ldp xe do anh hudng cua hifn tugng trugt bSn khi xe quay vdng hoac chuyen lan Hai gdc nay diu lien quan tdi xac dinh luc b6n
Hinh 1 Ddng luc hoc bdnh xe
Cac lyc dpc F^, xuat hifn khi xe chuyen ddng tren dudng va cd xu hudng giam khi phanh Lyc ben F se xuat hien khi cac gdc khi xe quay vdng hoac chuyln lan Tai thdi dilm ldp nhan cac phan lyc tii dudng thi cung xuSt hien cac mo men M , M, M do cd cac gdc dat banh xe
x' y' z e
Md hinh ldp co ban ban thyc nghifm dua
ra bdi H.B Pacejka da dupc cac nha nghiSn ciiu ciing nhu cac nha san xuat sir dyng kha phd biSn
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TAP CHI CO KHf VlfiT NAM, Sd 11 nam 2015
Trang 3NGHIEN CUTU-TRAO Ddi
vi ket qua kha chinh xac va cd the ap dung trong
vifc tinh toan, md phdng tren may tinh Md hmh
nay, thyc chat la mgt cdng thiic gdm nhiing ham
toan hpc thdng thudng dugc xay dyng tren ca sd
kit hgp ly thuylt vdi thyc nghifm: Tuyln tinh
hoa dac tinh luc b6n vdi cac he sd hifu chinh
dya tr6n be day cac ket qua diuc nghiem Cdng
thuc ndi tieng nay dugc gpi la "Magic Formula",
dupe the hien nhu sau:
:v(:e)-D.sin{c.tan-'[fix-£(Sjc-tan-'Sx)]|(Ll)
x = X + S,
(1.2) (1.3)
vi du, khi xac dinh F^ thi cac he so trong
cong thuc (1.1) dugc xac dinh nhu sau:
SC£>, = (bj F / +b^.F^)e-'^''' (1.5)
E,=(b,.F,+b,).¥, + b, (1.6)
C,=6„.e°-^'°^''' (1.7)
S,.=b,F,+b,„ (1.8)
Trong đ, Y{x) the hifn gia tri dau ra (lyc
dpc, lyc ngang, mdmen tu dgng dn dinh, ) cdn
X the hifn gia tri dau vao (dp trugt, gdc Ifch
ben) He sd B gpi la hf sd do ciing, C la hf sd
dgng dudng, D la he sd dmh, E la hf sd cong S^
Sj^ la khoang dich tryc Cac he sd nay dac tnmg
cho kit ciu, dac dilm ciia loai ldp rieng
Hinh 2 Dd thi bieu thi quy ludt thay đi cdc thdnh
phdn luc theo Pacejka
Nhu da d§ cap d tren, md hinh co ban cua Pacejka khdng tinh anh hudng cua su bien thien tai trpng thing dung va gdc nghieng ngoai
Y (gdc camber) dupc coi nhu rat nhd (bang 0) Ndi dung chinh cua bai bao trinh bay ket qua khi phat triln md hinh co ban cua Pacejka đ xem xet anh hudng ciia sy bien thien tai trgng thang dung va gdc y tdi gia tri cua cac thanh phan lyc tgi viing tuong tac Idp dudng
Qh xac dinh lyc dgc F (1.1) can phai cd
11 hf sd \ ^ b,(j, khi tmh den sy thay đi tai
trpng thang diing F^ tac gia chpn cac gia tri cua cac hf sd b,, bj, b^, b^ khac 0 Tuong tu nhu khi xac dinh md men M^ khi tinh den sy thay đi tai trpng thang diing F^ thi cac he sd c,, c^, Cj se thay đi va luc ngang F la a,, â, ậ Khi cd sy anh hudng cua gdc nghieng y thi cac hf sd â, a,(,,
a,„ a,^ va c„ c„ c,,, c„ duoc them vaọ Vdi each
13' 14 5 ' 6 ' l l ' 14 • ,
thuc hifn nhu vay, mdt vai ket qua chinh ve sy thay đi gia tri ciia cac thanh phan lyc tgi vung tiep xuc gifta ldp va dudng se dugc trinh bay va phan tich trong phan tiep theo cua bai baọ
3 KET QUA NGHIEN CtTU VA BAN L U ^ Ddi tugng dugc lua chgn de nghien ciiu
la mdt ldp xe tai cd ky hifu 315/70R22.5XZA, cac thdng sd co ban dupc the hien trong phan bang 2 De nghien ciiu tinh toan, mdt sd gia thiet sau dupc su dyng: (i) Mat dudng la phing va cimg tuyft đi, (ii) BChdng xet din anh hudng cua cac yeu td nhu nhift do, dp am
Tu ket qua ciia md hinh dugc the hifn tai hinh 3 va hinh 4, cd the nhgn thiy tuong tac Idp/dudng, dya theo md hinh Pacejka md ta thyc nghifm kha chinh xac ve mdi quan hf gifta lyc dpc Fj^, lyc ngang F md men M^, vdi cac gdc dat vao banh xe dan hudng va tai trpng thing dimg Cac ket qua phan aidi diing ban chit vat ly va
quy lugt lam vifc cua ldp xe khi lan tren dudng ^
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TAP CHI CO KHf VIET NAM, Sd 11 nam 2015
Trang 4NGHIEN CUlU - TRAO D(!)l
Hinh 3 Do thi luc doc F khi gamma thay ddi
6000
-2000
KhiF^
/ "
1
Hinh 4 Do thi luc dgc F khiF thay ddi
Can eft hinh 3 va hinh 4, ta thiy luc dpc ^
Fx chi tuyln tinh khi dp h ^ g t s = (-10% - 10%)
Vi vay, vifc thay ddi gdc nghieng y va tai trgng
F , trong viing nay khdng anh hudng nhiSu tdi lyc dpc F^, khi ngoai vimg tuyen tinh s ^ (10%
- 15%) dd la vimg lam vifc cua hf thong chdng
bd Cling banh xe khi phanh (ABS) Tren thyc t l , khi phanh xe hoac quay vdng se cd sy phan hd lgi tai trpng gifta ciu trudc va cau sau va giua hai banh xe tren cimg mdt ciu KSt qua nghien Cliu tten cho thiy ring, khi nghien cftu hf thong phanh ABS, khdng t h i khdng xet tdi anh hudng
ciia gdc nghieng y, tai trgng thing dung F^
Dilu nay, tuang ty vdi F^, M^ chi thay ddi tuyln tmh khi a ^ (-5% - 5%), khi ngoai
vimg tuyen tinh gdc nghi§ng y va tai ttpng F^ anh
hudng rit nhilu tdi luc F va md men M Ket qua nay dugc the hifn rd trong bang 1
Bdng 1 Anh hudng ciia goc nghieng y vd tdi trong thdng dung Fz
STT
Fz
y
Bien do thay dot
0%
5%
10%
0%
5%
10%
F.,„„,(N)
5780
6077
6375
5780
5504
5234
F^.„,(N)
7116
7442
7765
7116
7215
7316
M.(„„,(N.m) 214,2 223,2 232,4 214,2
225 235,8
Tit bang 1 ta thay khi goc nghitog Y= 0° va tai trong F^ = const thi luc dpc F,^, lite ngangF^, m6 men khong thay d6i, khi tai trpng F^ tang 5% thi lite dpc F^^^^,^, se tang thSm 297 N (4,9%), lire ngang F^(_^_,_, tang them 326 N (4,4%), momen 1V1^| ^, se tang them 9 N.m (4%) Vi vay, su anh hu6ng
cua goc nghieng y va tai trpng F^ Skn gia tri cua cac thanh p h t o luc tai vung tuong tac 15p/ducmg la
rat ro rMig Khi y thay doi va tai trpng Fz ^ cpnst, nhan thiy ring luc dpc F^ giam di, con lite ngang
Fj, tang len, diSu nay ehp thiy mo hinh ntog cao da mp ta dupc m6i hen quan giila luc dpc va luc ngang va hpto toan phu hgp voi nhfhig dinh lu^t co b t o da dupc svt dvmg khi nghiSn euu dpng luc hpc Icp xe Ito tren ducmg [1]
ISSN 0866 - 7056
TAP CHf CO KHl VlfiT NAIM, S6 11 ntoi 2015
Trang 5NGHIEN C U T U - T R A O D O I
Cac ket qua tren cho thiy, vifc phat trien md hinh tuong tac ldp dudng ca ban cua Pacejka bang each them vao mpt sd hf so de xem xet anh hudng ciia gdc nghieng ngoai y va sy bien thien ciia tai trpng thang diing Fz, cho chiing ta ket qua chinh xac han Md hinh nang cao cd the ap dyng trong san xuat, thiet ke ldp xe cung nhu nghien ciiu cac van de phiic tgp ve ddng luc hpc chuyen dpng cua 6 td Tuy nhien, cung giong nhu chinh md hinh ca ban ciia Pacejka, mudn tinh toan cho mpt logi tdp cu the can phai xac dinh rat nliieu he sd bang thuc nghiem Do vay, vifc ap dyng md hinh nay trong thyc te gap khdng it nhung khd khan Mgt hudng nghien euu tiep theo dugc dgt ra la chiing ta se di xay dung mdt md hinh mdi dya tren md hinh Pacejka nhung don gian va hon it thdng
sd hon ma ket qua van dam bao dugc do chinh xac trong gidi han cho phep ciia bai toan.<»
Bang 2 Mdt sd thdng sd cua ldp xe:
STT
1
2
3
4
5
Thong s6
B t o kinh lop xe
Khoi lugng lop xe
Ap suat khi nen
Bto kinh lop khi chiu tai trpng dinh muc
Dp Cling bien dang thtog dung cua Ipp
Gia tri
0,507
104
9 0,472
9000000
Don vi
m
kg
b
m N/m
Ngay nhan bai: 28/10/2015
Ngay phan bien: 12/11/2015
Tai lien tham khao:
[1] Nguyin Phiic Hieu, Vii Diic Lap (1999), Ly thuyet d id Qudn su Hoc vien Ky thuat Quan sy Ha Npi [2], Nguyen Xuan Dung (2008), Md hinh ddng luc hgc bdnh xe ddn hdi lan tren dudng cung, Chuyen de
Tien sT diuoc de tai Xay dyng mo hinh dpng luc hoc quay vong xe 6 to quan sy nhieu cau trong cac he mo phong, Hpc vien Ky thuat Quan su
[i\'^^jyhii:T\xdn%Smk{2QXyT)\Dgngluc hgc chuyen ddng thdngvdquc^
Luan vlin Thac si k j thuat, Hpc vien Ky thuat Quan su
[4] Vu Ngpc Tuin (2009), Md phong tuang tdc ldp d id vd mat dudng, wig dungkhdo sdt chuyen dgng thdng
cua d to Tap chi Co khi Yiet Nam, so 142
[5] Pham HomgMinh (2013), Nghien cim dnh hudng (ma mdt sd tham so kit cdu den kJid ndng quay vdng
cua dodn xe, Luan van Thac sT ky thuat, Hpc vifn Ky thuat Quan sy
[6] Hans B Pacejka (2002), Tyre and Vehicle Dynamics, Butterworth Heinemann
ISSN 0866 - 7056
TAP CHl C O KHI VIET NAM, Sd 11 nam 2015