KHOA HOC - CONG NGHE
Tap Chi GTVT 10/2009 I
ANH HlTCfNG CUA THANH ON DINH ^
DEN DAO DONG NGANG OTO /v^
T S . N G U Y E N T U A N A N H - Trudng Dai hgc GTVT P G S . T S . V U D U G L A P - Hoc vien Ky thuat Quan sU T h S . T R A N T H A N H A N - TrUdng Cao ddng GTVT
Tom th: Cac thanh on dinh (hay thanh chong l^c) dupc trang hi tren oto nhim han che dao dgng ngang ciia than xe khi dtd chuyen dpng tren di/dng khong bang ph^ng hoac khi di vao duong vong. Nh^m danh gia anh hi/ong cua thanh on djnh den dp em dju va an toan chuyen dpng cua oto, bai bao gioi thieu phUong phap tinh toan cac luc va mo men on dinh, sau do dua ra cac ket qua khao sat va danh gia dua tren mpt mo hinh on dinh ngang bdn bac tif do.
Abstract: Most of modern vehicles are equipped with stabilizators (or anti-roll bars) to reduce roll motion of the car body during cornering or driving on uneven roads. This paper introduces a method for formulating the stabilizator force and moment and their influences on vehicle comfort and safety criterion.
I. OAT V A N OE
An toan giao thdng ludn la v i n d i d u o c quan tam dac biet tren toan the gidi, nhat la d cac nu'dc dang phat trien n h u nu'dc ta. Lat xe la mdt trong nhu'ng tai nan giao thdng nghiem trong gay nhieu thiet hai ve n g u d i va cua [4, 5, 6], Nguy hiem nay cd the du'oc han c h i b i n g each su^ dung cac thanh dn dinh n h u dupe trang bi tren h i u h i t cac loai d td hien nay, Thanh dn dinh t h u d n g du'pc che tao t u thep dng cd dp cung chdng xoan cao, lien k i t hai banh xe khac phia tren cung mot true (tai chdt A, va Al) vdi khung xe thdng qua cac gdi d d cao su (B, va B.), Hinh 1.
Hinh thang lai
/ Don treo tren
r-'v
Thanh on dinh
Goi d o tren khung xe
./
Hinh 1: He thong treo doc lap v&i thanh on dinh Nhd kha nang chong x o i n , thanh dn dinh cd t h i han c h i dieh c h u y i n tu'ong doi giua hai banh xe khac phia va SU' lac ngang cua than xe khi dtd di vao du'dng vdng hoac chuyin dpng tren dudng khong b i n g p h i n g , do dd lam tang tinh on dinh cua 6 to, Tuy nhien, viec tang dd cung chdng l i e than xe b i n g each sd dung thanh dn djnh cd t h i lam giam dang k i dd em dju chuyin dpng cua d td, Muc dich danh gia mdt each toan dien anh hudng cua
thanh dn dinh den dao ddng ngang cua d td, trudc het bai bao gid'i thieu phuong phap xac dinh lue va md men do thanh dn dinh sinh ra, sau dd tien hanh khao sat anh hu'dng cua dp cung thanh dn dinh den dp em diu c h u y i n dpng va kha nang chdng lat khi d td quay vdng dua tren mpt md hinh dao ddng ngang bdn bac t u do,
II. L l / C VA MO MEN ON OINH
Khi dich chuyen t u o n g ddi theo p h u o n g thang dung giu'a banh xe va than xe d ben phai va ben trai khac nhau. A: „. T^I^i II. tren thanh i n dinh, vdi do cii'ng gdc k ,,, [Nm/rad], se x u i t hien mot md men xoan .My [Nm] can lai chuyen dich t u o n g ddi giu'a cac banh xe, Hinh 2.
, \ / , = A = A
.\_-
-Ar(1) Md men nay se tao ra cac ILTC chdng l i e F ^ [N] tae dung len banh xe va F,., [N] tac dung len than xe:
/ - • , -P.
-F
A/^ _ k
F„i
(\--|, - A r J .
(2){^.-^,i) p;
Hinh 2: LiK va mo men on dinh Trong cdng thuc (2) va (3), cac thanh phan:
A„ = A , „ - ' , - \ a A j , = A , „ - ' ' - . [N/mJ
<•" i I.,
(4) cd t h u nguyen cua dp cung p h i n t d dan hdi trong he thdng treo, d u p e gpi la dp cu'ng chdng l i e quy ddi, dac trung cho anh hu'dng cua cac thdng sd hinh hpc ciia thanh dn dinh. Khi dd md men dn dinh than xe do thanh chdng l i e sinh ra d u p e xac djnh n h u sau:
M i,=y-\si ',= 2A,, / „ ( . V r , - A r , )
• 2A (5)
KHOA HOC - CONG NGHE
trong dd :'s [m] va :'i [m] la dich c h u y i n t h i n g ddng cua than xe va banh xe tai vj tri lien k i t vdi thanh dn djnh ( d i i m A va S), cac chi sd 'V, /" t u o n g dng b i i u thi banh xe ben phai va ben trai.
III. MO HiNH ON OjNH NGANG QUA 6 TO
Cae li/c va md men chdng lac d p h i n tren se du-pc cdng thdc hda trong phuong trinh c h u y i n dpng xay dung tren md hinh nghien cdu tinh dn djnh cua d td trinh bay dLrdi day,
3.1. Mo hinh va cac gia thiet
Hinh 3 t h i hien md hinh dao ddng ngang nghien euu tinh dn djnh eua d td cd k i d i n anh hu'dng eua thanh chdng l i e va tam l i e ngang than xe. Than xe ed khdi iLrpng nis [kg], md men quan tinh ,/v [kgm^], d u p c lien k i t vdi cac banh xe cd khdi iLfong ;»,, [kg] thdng qua cac p h i n t u dan hdi ed dp cdng AJN/m], p h i n t d giam c h i n cd he sd can Jv [Ns/m], va thanh chdng l i e ed dp eUng gdc Av„ [Nm/rad], Cae banh xe cd dp cUng A, [N/m] d u p c xem nhu' cae c h i t d i i m khdng cd md men quan tinh, Dac tinh eua p h i n t u dan hdi, thanh chdng l i e va giam c h i n gia t h i i t la t u y i n tinh, bd qua he sd can cua ldp,
Md hinh ed t i t ea b i n bac t u do: hai bac t u do cua than xe la djch chuyen t h i n g du'ng eua trpng tam zc va gdc l i e ij) quanh tam lac ngang R, hai bac t y do cdn lai la djch chuyen t h i n g dUng eua trpng tam banh xe ben trai z,., va banh xe ben phai c,,.
Hinh 3: Mo hinh dao dong ngang cua 6 to
Ngoai luc tac dung len md hinh gdm luc quan tinh li tam Fy x u i t hien khi d td quay vdng va cac m i p md mat d u d n g cd bien dp q, va </,,
3.2. Phu'cng trinh chuyen dong
Sau khi giai phdng lien k i t , v i i t cae phirong trinh can bang lue ddi vdi than xe va eae banh xe, va phuong thnh can b i n g md men quanh tam lac R eho than xe, ta nhan dupe he phirong trinh chuyin ddng cua md hinh nhu sau:
'<=c+{fKSi+^nsi+F'i^i) + {F,sr+F'nsr + ''LS,) = 0- (&)
-[{'',si + F-nsi)-iE,s, + F,„i)]p-^M,,,,=0. (7) -{F;.„+Pns,+f,n) + ki (--,,-<//) = 0- (8) -(^.:sv + /^as> + ^:,r,.) + A, (--,,--'/,.) = (). (9)
"('-(/
Trong dd F,, va F„s la lu'c sinh ra do phan tu- dan hoi va p h i n t u giam c h i n cua he thdng treo, F,s va F,, tu-ong dng la luc t d thanh dn dinh tac dung len than xe va banh xe:
rnsi..='ls{=su-=r4 < " '
^,..,=±^.[(4-;-)-(4-;,)]- ('2)
Gia t h i i t gdc l i e than xe nhd, d - 1, va s d dung cac quan he hinh hgc:
ipi.. 14
cae p h u o n g trinh (6)-(9) ed t h i du'pc khai t h i n va viit lai d dang ma tran n h u sau:
M y + D y + K y ^ h . (l?) Vdi ma tran khdi l u p n g :
M =diiig\\^ni^. {^i)i^ltl+J^^. Ill . nil (16) ma tran he sd can:
2(/c
0 li-.d.,
ma tran dp eung:
2k.
K =
2':,ks
f'A
-A,
-2'«A-,,
^ ' ' s
- ^ A .
7-^^
-^-f'u
~^k,^k,
(17)
V '"
^ A
^ A
a-^k,
^ ^ A , ,
- ^ A , + A ,
^ A
V 'ir
, ( 1 8 )
vec t o cae lue suy rdng:
// = [0. Wy/i,//,, A, r/,. A,,r/,. (19) va vec to cae tpa dp suy rdng, bao gom bdn bac tu do eua he:
y = [-r- 'P- -n- - r , ] ' • (20) Luu y cac thanh p h i n trpng l u p r cua than xe
va banh xe ludn can bang vdi lue nen ;;i eua Id xo va ldp nen khong xuat hien trong cac pi •. ^ n g tnnh dpng luc hoc d tren.
Oat:
KHOA HOC - CONG NGHE Tap Chi GTVT 10/2009
Z=\^P. Fi. Fi^.
: , , - - , , - ] • (21) (22)
" = [",• 'A- 7 , . ] ' . (23) lan lupt la vec t o trang thai, vec to cac thdng sd ra, va
vec to eae kich thich, p h u o n g trinh chuyen ddng (15) ed t h i d u p e bieu dien d dang khdng gian trang thai:
(24) I .Y = .l .V + B ll.
\ Z = C .X + E ll.
vdi .1, B, C, F la cac ma tran he t h i n g dupc xac dinh n h u sau:
/
.1B =
0, ' 4 i 4
M D
0. , 1 M H
, H = 0 0
0 0 kl
0
o"
0 0
^'_
E
^ Ip <> 0
0 - A , . 0 0 0 -A,
M~ D
,?, = [ 0 . 1 . 0 . 0 ] ,
(26)
(27)
(28)
(29) (30) (31)
IV. KHAO SAT ON DjNH NGANG CUA O TO Trong p h i n nay, anh h u d n g eua thanh on djnh d i n cac dac trung eo ban v i dao ddng ngang eua d to se dupe khao sat va danh gia dpa tren p h i n mem MATLABSIMULINK,
4 . 1 . Cac c h i tieu d a n h gia dao d d n g n g a n g 6 t o Trong t r u d n g hop tdng quat, hai chi tieu c o ban dupc s u dung d i danh gia dao ddng 6 td la dp em dju chuyin ddng, t h u d n g dae trung bang gia tr; binh phuong trung binh eua gia tdc dao dpng thang dung cua than xe, va dp an toan chuyen ddng, t h u d n g dae trung b i n g dp lech chuan cua gia tn tai trpng ddng F'^, so vdi gia trj tai trpng tTnh do cac banh xe tac dung xudng mat d u d n g [ 1 , 2, 3],
Khi d td di vao dudng vdng hoac chuyin dpng tren dudng ed bien dang khae nhau giu'a hai ben banh xe, gdc l i e ngang than xe ed anh h u d n g ldn d i n dp em diu va an toan c h u y i n dpng cua d td. Trong t r u d n g h p p nay, gia trj gia t i e l i e ngang than xe thudng Idn h o n n h i i u so vdi gia t i e dao dpng theo phuang t h i n g d u n g , Ddng thdi, khi gdc l i e ngang than xe qua ldn ed t h i d i n d i n hien t u p n g tach banh xe khdi mat d u d n g , lam m i t tinh d i i u k h i i n va cd t h i gay lat xe. Do dd, khi nghien CUU dao ddng ngang cua d td, hai chi tieu sau day d u o c s u dung:
Chi tieu ve do em dju:
CF-
" T
\'f-(t)ilr
rad- Chi tieu v i an toan c h u y i n ddng:
5 r = mean(/?), - 1 <R=^'''~ ^'-' < 1 F +F
(32)
(33) Trong eae cdng thuc tren, CF la gia trj binh p h u o n g trung binh cua gia tdc l i e ngang than xe; .STgia tri trung binh cua he sd chdng lat R. R = = \ khi phan lue phap t u y i n tir mat d u d n g tae dung len banh xe ben phai, trai F/,. I - 0, nghTa la khi banh xe ben phai hoac ben trai tach khdi mat d u d n g . T r u d n g hpp d td c h u y i n ddng t h i n g tren d u d n g b i n g p h i n g , F^, = F/,, khi dd CF = 0 va .S7" = 0, day la gia tri tdi u u v i dp em dju va an toan c h u y i n dpng cua d td,
4.2. Ket qua khao sat
D i t h i y rd anh h u d n g cua thanh chdng lac d i n dao ddng ngang cua d td, d td d u p e md phdng chuyen ddng quay vdng deu tren d u d n g b i n g vdi gia tdc h u d n g tam
«, 7^0, cac kich thich tir mat d u d n g r/, = q, = 0. Md hinh dn djnh ngang cua d td trong MATLAB SIMULINK d u p e the hien tren Hinh 4.
Inpuls
:Ax+Bu : Cx+Du
Phi"
Fzl Fzr
State-Space Outputs Plots Hinh 4: Mo hinh MATLAB SIMULINK
Vdi cac thdng sd cua d td khao sat cho trong Bang 1, ta cd t h i nhan d u p c eae k i t qua md phdng n h u trinh bay tren Hinh 5.
Bang 1: Thong so cua oto khao sat
1 2 3 4 5 6 7 8 9 10 11
Thong s6 Kh6i lu'O'ng than xe Khoi lu'ong banh xe
Mo men quan tinh cua than xe He so can cua giam chan Dp cu-ng ciia ph4n tu' dan hoi Dp CLfng cua lop
Khoang each tam lac than xe Vet banh xe
Kich thu-oc thanh on dinh Kich thifoc thanh on dinh Kich thu'oc thanh 6n dinh
Ky hieu Ills nil
Js ds ks kl I'K
l,v 'A
'B c
Gia tri 3860
200 4500 20000 95000 280000 0,5 0.8 0.5 0,3 0,2
Don vi kg kg kgm^
Ns/m N/m N/m m m m m m Kich thich d i u vao la gia tdc hudng tam ay tang d i n t u 0 d i n gia tri dn dinh 3 [m/s""] {Hinh 5a) t u o n g ij'ng vdi t r u d n g hpp d td dang chuyen ddng thang dot ngpt quay vdng d i u vdi ban kinh va tdc dp khdng ddi.
K i t qua md phdng cho thay, khi tang dp cung cua thanh dn djnh t u A,„ = 0-3000 [Nm/rad], gia trj ldn n h i t cua gdc l i e than xe d giam t u 22° xudng cdn 7'^ (Hinh 5b). lam giam dang k i s u di c h u y i n tai trong giCra cac banh xe phia trong va phia ngoai tam quay vdng, O gia tn A„, = 3000 [Nm/rad], tai trpng banh xe tac dung xudng mat d u d n g dao ddng xung quanh gia th tai trpng tTnh r^,- F/, = 2 0 0 0 0 [N], (Hinh 5c va 5d), khi dd he sd chdng lat eung dao ddng xung quanh gia th tdi u u R = 0,
KHOA HOC - CONG NGHE
{Hinh 5f va 5h). Tuy nhien khi tang dp cung cua thanh dn dinh, gia tdc lac than x e ^ t a n g nhanh lam giam dd em diu cua d td, {Hinh 5e va 5g).
Cae k i t qua t u o n g t u eung nhan d u p c khi md phdng d td c h u y i n ddng t h i n g tren d u d n g m i p mo, tuc la khi n, = 0 va I/, hoac q, 7^).
Arigis ul tue DaiBcc
b)
1
Tang
• • ^ ' - " : • - -
KAO
—"=
n:i=:toan giam. va nguoc lai. Mau thuan giu'a hai chi tieu nay ddi hdi nguoi thiit k i phai dua ra q u y i t dinh phu hpp, dam bao s u thda hiep tdi uu giu'a hai chi tieu ddi lap.
Day chinh la nhiem vu cua bai toan tdi u u hda da mm- tieu, trong do cac tham sd k i t c i u eua he t h i n g treo d u o c tinh toan tren quan d i i m tdi u u hda d i n g thdi ca hai chi tieu v i em diu va an toan chuyen ddng [ 1 , 3],
14
";
.;,
17 1 5
^ 1
LL 1
0 5
in'Right vpr;,c^! L o a *
.A - - f • - ' - - - " —
W'^ff—-^
'W .'-L'
T a n g KAO
5 I | ; l
^o|Nm..rad| 1-
Hint) 5; Ket qua mo phong bang MATLAB SIMULINK Hinh 6 the hien mdi quan he giua chi tieu ve dp em diu va an toan chuyen ddng khi thay ddi gia tri cua do cu'ng thanh dn dinh, Mdi vdng trdn tren hinh ve t u o n g ij'ng vol mpt gia tri xac dinh ciia dp cung Aj„, Cd the t h i y khi chi tieu v i dp em diu tang thi chi tieu v i an
0 2 u 4 u 6 IJ y R I * Satet'.,.' C:riterion Hinh 6. Quan he giira chi tieu em diu va
an toan chuyen dgng V. KET LUAN
Hien nay, thanh dn dinh ngay cang d u p e s u dung pho b i i n nhd lam tang dang k i kha nang chdng lat eua 6 td, Trong bai bao, lue va md men chdng l i e than xe do thanh dn dinh sinh ra d u p c tinh toan va cu t h i hda trong phuong trinh c h u y i n dpng cua md hinh dao ddng ngang bdn bac t u do, Cac k i t qua md phdng d u a tren phin m i m MATLAB SIMULINK da chung minh hieu qua ro ret cua thanh dn djnh trong kha nang chdng lat cua d td, ddng thdi eung chi ra s u mau thuan giO'a hai chi tieu quan trpng danh gia c h i t lupng dao dpng cua d td la chi tieu v i dp em diu va chi tieu an toan c h u y i n ddng, Mau t h u i n nay chi cd t h i d u p e giai q u y i t b i n g phuong phap tdi uu hoa da muc tieu - van d i se d u p c trinh bay cu the trong cae sd bao tiep theo,/, ••.\ •
TAI LIEU THAM KHAO
[1], Bestle, D., Analyse and Optlmierung von Mehrkorper-systemen. Berlin: Springer, 1994.
[2]. Jazar, R. N., Vehicles Dynamics. Theory and Application. Berlin: Springer, 2(iii,'<.
[3]. Nguyen Tuan Anh, Application of Optimization Methods to Controller Design for Active Suspension. Ph, D, Thesis, Barandenburg University of Technology Cottbus, 2006.
[4], Sampson, D, J. M,, and Cebon, D., Active Roll Control of Single Unit Heavy Road Vehicles. Vehicle System Dynamics, 2002.
[5]. Schofield, B., Vehicle Dynamics Control for Rollover Prevention. Ph.D. Thesis, Lund University, Sweden, 2006.
[6], Whitehead, R,, Travis, W,, Bevly, D. M„ and Flowers, G., A Study of the Effect of Various Vehicle Properties on Rollover Propensity. SAE International, 2004,
GIAO THONG DO THI H A NOI.
(Tiep theo trang 51)
banh ea nhan hon la xe 4 banh ea nhan), se lam giam Idpng nhien lieu sd dung va tdng mdc phat thai theo km hanh khach. Khi so sanh cae k i t qua khi tieu chuan phat thai chau Au ddde ap dung cho van chuyen khdi Idpng ldn nam 2 0 2 0 , hai gia trj nay chenh nhau tdi 2 0 % do mdc dp phd bien khae nhau c u a G T C C .
3. Mdc dd ach t i e giao thdng se lam gia tang se tang luu Iddng phat thai va giam hieu s u i t nhien lieu eua cac phUdng tien ea nhan. N e u khdng ed cac bien phap kiem c h i tang trudng giao thdng bang xe ndi ehung, dae biet la xe ca nhan, nhien lieu sd dung va phat thai cung se eang thap, Viee tiep tue chuyen ddi tu xe 2 banh sang xe eon se lami tang dang ke luong nhien lieu sd dung, ngay ea kt-< cae xe con ed hieu s u i t eao. Viec chuyen ddi nhu N. : u n g se gay ach t i e giao thdng nghiem trpng do ,eu dien tich dudng phd d nhieu nPi trong Thanh phd H a M •
