Tuyen tap bao cao khoa hgc Hpi nghi Khoa hgc ky thudt Do lufirng toan quoc ISn thi TV HdNgi,ll-200S
yi MOT HE THONG DIEU KHIEN, DO LUdNG KIEM TRA CHAT LUONG BIEN AP XOAY SIN-COS DUNG TRONG CAC HE THONG
TINH TOAN 6 KHI T A I QUAN S U
Duang Qudc Khdnh, Trdn Bdc Tnmg, Do Tudn Cuong, Dodn Vdn Thu;) Vien Ten Ida- Trung tdm KHKT CN Qudn su
I. M(5 DAU
Bifin ap xoay sin-cos (BAX) Id thanh phdn co ban, quan trgng nhdt cua cac hfi thtfng mdy ti'nh co - dien dfi giai nhflng bdi todn tfnh todn phic tap dugc ding phfl bifin trong cdc khi tdi quan su. Chdt Iugng bifin dp la yfiu ttf anh huflng Ifin nha't tfli sai stf tfnh todn cia mdy tfnh va nfi dugc kifim tta khi xudt xuflng tai noi san xudt (cdc bifin dp xoay sin-cos trong khf tai hien nay nttflc ta chtta san xudt dttgc). Dfi dam bao duy Ul ky thudt va sia chtta thay thfi, nhu cdu chfi tao thifit bi cfing nghfi ttang bi cho cac day chuyfin sia chtta khf tai Id rdt cdn thifit.
II. CAU TAO VA NGUYEN L^i LAM VlfiC CIJA BIEN AP XOAY SIN-COS 2.1. CSu tao:
Cdu tao bifi'n dp xoay sm-cos mfi ta ttfin hinh ve I:
/fC3
Hinh 1; CS'u tao bifin ap xoay sin-cos
Bifin dp xoay sin-cos cfi 2 phdn chinh: Stator va Roto. Tifin Stator ddt 2 cufin ddy Cl- C2 vd C3-C4 cfl vi tti vuflng gfic vfli nhau. Tren Roto cflng dat 2 cufin ddy P1-P2 vd P3-P4 cfl vi trf vuflng gfic vfli nhau.
2.2. Nguyen ly hoat dgng:
Khi cdp cdc tt'n hieu tudn hodn hinh sm vdo cdc cufln ddy Stator CI-C2 vd C3-C4 uen cdc cufln ddy Roto PI-P2 va P3-P4 cung xudt hifln cdc tfn hieu tudn hoan hinh sin. Bien dfi vd pha cdc tm hifiu ttfin 2 cufin day Roto P1-P2 vd P3-P4 phu thufic vdo bifin dfi cdc tfn hieu Mnh sm cdp vdo cufln ddy C1-C2 vd C3-C4, ti stf stf vflng cdc ddy Roto vfli Stator vd phu
thuflc vdo Vl tn goc cua Roto. ' VI du: Khi ta cSp tm hieu hinh sin A.sin((i)t) vdo cufln ddy C1-C2 ttfin Stator, tfn hifiu
o 2 cufin day ttfin Roto nhu sau:
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Tin hifiu t i PI-P2: Up,.,; = K.A.sma.sin(o)t) Tin hifiu ttt P3-P4: Up3.„ = K.A.cosa.sm(cot) Trong dd:
A - Bifin dfi tin hifiu hinh sin cdp vao cufin ddy CI-C2 Q) - Tdn stf gflc tin hifiu hinh sin cdp vdo cufin ddy C1-C2 K - Ti sfi sfl vflng ddy PI-P2(P3-P4) vd CI-C2 a - Gflc vi tri cua Roto
III. THUAT TOAN KIEM TRA BIEN AP XOAY SIN-COS
Theo nguyfin ly boat dflng cia BAX ta thdy: nfiu ta cdp tin hifiu hlnh sm A.sm((Bt) vdo cufln ddy C1-C2 trfln Stator thi t i cdc tin hieu fl 2 cufln day P1-P2 vd P3-P4 tren Roto chung ta xdc dinh dugc gfic vi tri cia Roto nhu sau:
„ K.A.sina.sin(ci)t)
^"~F1 ^T^""'^" =" a = arctg(B) K.A.cosa.siniwt)
Ttt kfit qua ttfin chung ta cfi thfi ding phuong phdp phan chttng dfi kifim tta BAX cfl dat tieu chudn ky thuat hay khflng? Tic la: gia s i BAX cdn kifim tta Id ttft, ching ta kifim tra dac tfnh dflng cua BAX thfing qua cdc gfic vi tti cia Roto t i 0° dfin 360° cfi dung theo tinh todn khfing? Nfi'u dung thi BAX Id ttft, nfiu khfing dung thi BAX khflng dat tifiu chudn ky thudt.
Ddu tien Roto fl mfit vj tri gflc bdt ky. Theo cfing thic ttfin, ching ta xdc dinh dugc gfic Og. Difiu khifin quay Roto di mfit gfic Aa, cung theo cflng thttc ttfin ching ta xdc dinh dugc gfic a,. Cfl a^ vd a,, xdc dinh dugc gid tri |a, -a(,|.
Tifip tuc quay Roto di mflt gflc Aa, ching ta xdc dinh dugc gflc cij. Cfi a, vd o^, xdc dinh dugc gid tri [a^ - aj |.
Thuc hifin tugng tu nhtt vdy dfin khi Roto quay hfit mfit vong, ching ta xdc dinh dugc gflc a„. Cfl On va ctn.,, xdc dinh dugc gid tri |a„ - «„_, |.
Thic hifin so sdnh cdc phdn t i cia tap J|a, -ao|, jor^ -oc^\, ..., \a„ -a„_^\\ vfii Aa(trong pham vi bdi bao, khflng dfi cap dfin phdn difiu khifin vi tri gflc cua Roto dfi xdc dinh chinh xdc gflc Aa thuc tfi). Kfit qua so sdnh phan dnh dac tinh dflng cua BAX. Luu dfi thuat todn kifim tta dac tinh dflng BAX thfi hien ttfin hinh 2.
IV. MO H I N H HE T H 6 N G KIEM TRA, DANH GIA CHXT L U O N G Blfisl AP XOAY SIN-COS
Hfi thtfng thuc hifin ba nhifim vu chinh:
- Difiu khifin chfnh xdc gflc quay Roto cia BAX, xdc dinh Aa.
- Cdp tt'n hifiu gia cho cufln ddy CI-C2 (hodc C3-C4), do Ittflng cdc tin hieu ttt PI-P2 vdP3-P4.
- Tfnh todn, x i ly, ddnh gid dua ra kfit luan.
Ttt thuat todn fl uen va yeu cdu ky thuat, bai todn phdn mfim phai giai quyfit cdc vdn dfi:
- Difiu khifin: difiu khifin vdo ra stf, difiu khifin dflng cg mflt chifiu theo vi tri - Do Ittflng tin hifiu
- Luu trtt dtt lieu, tfnh todn va x i ly
Hifin thi true quan
Khflng dat
C l B e g i n _ J ^
- Nap cac sd lieu ddu vao - i = 0
- Doc gia tri difin dp tfi P1-P2, P3-P4 - Tinh Oo
- Quay Roto mfit gde Aa - Xae dinh Aa thuc te'
Kfi't ludn
X
C^____END_J^
Hinh 2: Luu do thudt todn
i = i+l
Man hinh diiu khi^n va bi^n thi
;;=C; Modul A/D CPU
^1=^ Modul I/O
PLC: CQM1H, Man hinh: NT21
Di^u khi^n dfing CO
Xfily Phdn cfing
Tao gid tin bieu
Bien ap xoay
Hlnh 3: So do khdi he thdng
Va so dd khdi he tho'ng tnnh bay trfin hinh 3 gdm eae thanh phdn chinh sau:
- Khfi'i dieu khien, hien thi va xfi ly trung tdm(CPU, modul 1/0, modul A/D, man hinh dieu khi^n va hien thi)
- Khfi'i tao gia tin hifiu - Khdi difiu khien dong co - Kho'i xfi ly phdn cfing IV. KET LUAN
Vific ap dung thudt toan tren edn lam giam sai sd thang giang cua he thdng, cho phep xae dinh dac tinh dfing cua BAX ehinh xac hon.
Hfi thfi'ng sfi dung may tfnh PLC CQMIH va man hinh NT21 cua OMRON lam thifi't bi di^u khi^n, do ludng, xfi ly trung tdm nhung cung cd ih^ thay thfi' bdng cac hfi xfi ly khac nhu hfi vi xfi ly; mdy tfnh PC...
Mfi hinh nay da dugc dp dung thuc tfi' trong ch^ tao thie't bi ki^m tra, danh gid ehdt lugng bie'n dp xoay sin-cos (hinh 4) cho hai nha may sfia ehfia kbi tai eua quan dfii.
Hinh 4: Thiet bj kiem tra chat luong bie'n dp xoay sin-cos
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