NGHIEN CLfu - TRAO OOI Xay dirng mo hinh quan he nhan qua he thong lai oto CO tra luc thiiy luc phuc vu cong tac chan doan Establishing the causality model for hydraulic power steering system in technical diagnosis PGS.TS Nguyen Van Tan, TS Nguyen Vdn Dang, ThS Vu Quoc Bao Hpc vien Ky thuat Quan sy TOM TAT Bdi bdo dd de xudt phUcfngphdp xdy ddng mo hinh Quan he nhdn qud doi vdi he thong ldi co trd Itic thuy liic tren Oto, thong qua co the liia chon diidc tap thdng so phuc vu cho cong tdc chdn dodn tiep theo ABTRACTS The paper introduces a method to establishing the causality model for hydraulic power steering system in automobile, thereby selects a set of parameter for technical diagnosis DAT VAN DE MO HINH QUAN HE NHAN QUA Chan dodn ky thudt d td la loai hinh tdc ddng ky thudt vdo qud trinh khai thac sfl dung d td, nham bao dam cho d td hoat ddng cd dp tin cdy, hilu qud cao bang cdch phdt hiln, dfl bdo kjp thdi cdc hfl hdng va tinh trang ky thudt md khdng can phai thdo rdi cic chi tiet, cum, tdng thdnh cua ^^' ^ ^ ^ De chan dodn TTKT cua mdt ddi tflpng , ^ , , ^ ^ ° cu the, cdng vile ddu tiln Id xdy dflng md hinh chan doan, sau dd Ifla chpn tap thdng sd chan Md hinh quan he nhdn qud cua ddi tflpng chan doan la mpt Graf dinh hfldng G (X, U) dd: x- la tap cac nut bieu dien tap hpp cac thdng sd cua ddi tflpng chan doan; u - la tap hflu han cac canh dinh hfldng, nd bieu thj cdc quan he gifla cac thdng sd rilng bift dd xdc dinh hoac ta gia dinh Hfldng cua cdc i, A' u ^.i, - - u ,j^ 4.' ^-^ ^^ ^A^ canh phu thuoc vao hfldng tac dong gifla cac , Cd nhieu phfldng phdp xdy dflng md hinh dp dung vdi tflng ddi tflpng cu the, dd cd the sfl dung md hinh quan he nhdn qua J TAP CHf CO KHf VIET NAM • Tap cac tham sd X la tap cua cac tap sau: X = KKJ RKJ F ^V ^ E Trong dd: K = {kj, k^.-.k^} la tap cac thdng sd dau vao Sd 10 (Thang l" nam 7011^ NGHIEN CLfu TRAO 061 (K) cac thdng sd khdng phdi la cac ham trang thai, nhung hoat ddng cua he thdng d dang tdng thi phu thupc vao chung; R = {r,, r.^ r^J- Id tap cdc thdng sd dac tinh (r^) Nd chi mu'c dp thuc hien cac chuc nang ca bdn vd cdc qua trinh ma ddi tupng dupc ghep ndi lai; F = { f,, fj f }- Id tap cdc thdng sd chiic nang (f) chiing xdc djnh cdc qua trinh co ban dac trung cho hoat ddng cua he thdng (tap cdc thdng sd bilu hiln kit cdu); a Phan tich lua chon cac thong so (trang 134 tai lieu Tham khao 2) - Cdc thdng sd ddu vdo (k): Cdc thdng sd dac tinh (r): Cdc thdng sd chiic ndng (f): Cdc thdng sd phu (v): Cac thdng sd cdu tnic (e): Cdc hu hdng vd sir cd cua cdc phan tii he thdng (d): b Phan tich quan he giua cac thong so Cdc canh ndi cua nut Graph-mddel dupc E = { e,, e^ e }- la tap cdc thdng sd cdu dinh trin co sd cdc quan he tuong hd vd su phu tnic (e) biiu thj cdc tinh chdt vdt ly, hoa hpc hinh thudc cua cdc tham sd Hudng cua cdc canh thudc vdo hudng tac dung giiia cdc tham sd hoc cua cdc phdn tu thudc hi; Dl xdy dung Graph- mddel cua he thdng ldi can V = { V , v, v }- la tap cdc thdng sd bd phdi xem xet cdc quan he phu thudc vi du nhu: trp, dd la cdc thdng sd cua qud trinh bd trp diln song song vdi qua trinh chinh, nhung khdng - Dp ro vdnh ldi (fl) cua he thdng lai se bj tham gia vao qua trinh chinh vd thudng khdng anh hudng cua tinh trang mdn co cdu lai (el), dp quan trpng ro dpc, ro ngang cua true lai(e2), dp kin cua cdc van cua may nen su thay ddi quan he ddng Ngoai xay dung md hinh quan he hpc giiia cum co cdu ldi vdi khung xe (e5); nhdn qud vdi chiic nang chan dodn, can phdi xem xet tdi cac hu hdng, su cd (d) thudng xdy ddi Luc diiu khiin vdnh tay ldi (f2) phu vdi DTCD qua trinh su dung, md nd biiu thudc dp ro dpc, ro ngang cua true lai (e2), tinh thi nhu sir thay ddi trj s6(vupt qud gia trj cho trang an khdp cua cung rang vd rang (e3), phep) eua cdc tham so cdu tnic Trong md hinh sd vdng quay true khuyu ddng co (k5); chdn dodn cdc hu hdng ndy khdng dupc biiu thj nhu cdc nut ddc lap ma nd dupc biiu thj kit hpp - Dp ro vdnh tay ldi, luc dilu khiln vdnh vdi cac tham sd cdu tnic (e) tay lai (fl, f2) dnh hudng din xe mdt khd nang dn djnh chuyin ddng thing, mdt cam giac diiu XAY DUTVG MO HINH QUAN HE NHAN khiin, diiu khiin khdng chinh xdc, ldp bj mai QUA V l CAC TAP THONG SO HE THONG mdn nhanh, lop cdc bdnh xe ddn hudng bj mdn LAI OTO CO TRO L i r e THUY LlTC khac (f4,f5,f6,f7), mdi mdn nhanh, lech ldp;(f8) va gay lire diiu khiin khdng dn dinh He thdng lai bd tri tren dtd la mdt he thdng (f 17), ddn din mdt khd nang lai (£21); duoc td hop tu: nhiiu cac cum chi tiit khac nhau, Chung ludn cd mdi quan he mat thiit, va tuong Mdi liln he giiia cac tham sd dac tinh (r) hd lln di bao dam hieu qua va chdt lupng cdn lai va cac tham^ sd phu (v) la hien nhiln suy lam viec cua toan bd he thdng Tren co sd so dd tir cdc phdn tich trin nguyen ly, kit cdu va nhirng hu hdng TTKT cua ^ ^ Cac tham so ddu vao (k) dnh hudng din hi thdng qua trinh khai thdc, chung ta cd thi xac dinh duac cac tap thdng sd sau: hoat ddng cua he thdng lai dupc hilu nhu sau: cF= TAP CHf CO KHf VlfiT NAM *t* Sd 10 (Thdng 10 nam 2011) NGHIEN CLfu - TRAO D6\ LflC tac dung lln vdnh tay ldi (kl) dnh hfldng dp nhay vd tinh dieu khiln cua h | thdng ldi Sd vdng quay true khuyu dpng cd (k5) dnh hfldng tdc dp bdm dau dan den dnh hfldng tdi dp sudt vd Iflu Iflpng dau bdi trdn 3* Tinh ma trdn R^ = Rf Vdi ddu "*" nghia Id tinh dinh R, X Rj ta sfl dpng phip cdng vd phip nhdn Idgic cdc phan tfl cua ma trdn R, Tfldng tfl ta tinh chd cdc ma trdn den R = R =R"* I' I Tfl Ciic mdi quan he trin ta cd thi lap dxicfc mpt ma trdn vudng n x n Vdi n Id sd phdn tfl Xi Khi dd ma trdn R Id ma trdn dat dflpc cua (n- sd nut) Trong bdi todn ndy ta xet n = 80 Graph G (X,U) Trong dd, ddng thfl i bieu dien mpi quan h | md, Graph tfl dinh i cd dp ddi Cdc phdn tfl a[i,j] ma trdn dflpc tfl din n canh Ma trdn A va R Id ma trdn vudng gdn gid trj U nlu thdng sd i cd quan h | vdi dang n x n Khi tinh din R khdng can phai tinh thdng sd j (nghia la Graph- mddel cd canh din luy thfla bdc n Neu R,'^'= R,"^"^'^' thi R = R,"^' ndi tfl dinh i sang dinh j); thi a[i,j] = 1, ngflpc lai ( K