Cic bien d^mg 2D d tren tilp tyc dupc xii ly dl t?io hinh mSt trong cic nghien eiiu duiSi day.. Budc 1: Sau khi do dupc bien d ^ g 2D, tiln hdnh ldm min va chin tpa dp Z vdo cdt C trong
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V KY THUAT C A T LOT VA TAI TAO CAC MAT KHONG GIAN
TREN MAY CMM
TOMOGRAPHY TECHNIQUE AND REPRODUCnON OF 3D SURFACE ON PCMM
Tr^n Nam Thing
Cong ty C6 phiin Co khi 6 to Nghe An
T6MTAT
Bdi bdo ndy gi&i thiiu ca s& thiit kd mdy do biin dgng 3D kiiu tay robot dira tren mgt tay
do 2D(XY) dd co sdn Yiu cdu tinh todn de nhdn dipn dugc linh kipn dien tix vai ndng ltic vua du ddp ieng cdc yiu cdu ve dg chinh xdc nhdm tiit kipm chi phi ddu tu Qud trinh thiit ke dd bo sung them bdn trugt tiye Z, bg diiu khiin true Z, chi tgo ddu do tieu chudn vd viit phdn mim xu ly so lipu di tong hgp mat cong 3D Thiit bf sau khi kiim tra cho thdy, ddm bdo do chinh xdc kich thieac Uti0yeu cdu dgt ra cUng nhu dg chinh xdc vi hinh ddng hinh hgc Phirang phdp tiip cgn qua kiim chimg cho th^ stf phii hgp di phdt triin cdc mdy CO dg chinh xdc cao han naa
Tfr kh6a: Mdy do CMM kieu robot, phuang phdp so tdi tgo ngirgc, cdm biin do goc
ABSTRACT
This newspaper introduces the basis of designing 3D contour measuring machine of robot hand type based on one available 2D (XY) measuring hand Requirement for hardware is identified electronic components with sufficient capacity to meet the requirements of accuracy in order to save investment costs The process of design has added the Z-axis slide, Z-axis controller, standard probe manufacturing and written the software of data processing for synthesizing SD curved surface It is showed that there is the accuracy of dimension and geometry as well according to the requirement after testing Via proven approach, it is presented to be pertinent to develop more high-precision machine
Keywords: CMM of robot type, numerical method, reverse engineering, encoder
1 DJ^T V A N Bt, thach thuc phai vugt qua trong cdc thiSt kh giai
mS san pham
Nhu cAu do kiem tra, hoic do vol myc
dfch sd hda t^o dudng djch dao cho cac may Trong mgt so cong bd tnrdc day, chung
cdng CM dieu khien so la rit phd biln Tuy nhien, tdi da trinh bay each giai quylt vin dh dp chinh
do mky do CMM thupc d^ng d$c chiing nen \^ xae cua cdc contuor 2D [9,10] Bh xay di^g thuyet thilt kl mky, d$c bi^t la phin dam bao dp ni$t 3D tu du: li^u 2D, ckn c6 mpt gidi thu£it sdp chinh xdc ph^p do khdng dupc cdng bd Day Id xep cac contuor rieng le theo thu t\r do dupc '"
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Cdc du: Heu nay can dupc dinh d ^ g thich hpp
dl bilu diln dd hpa tren cac phan mdm dd hpa
cd ho tra CAM, nhim su dyng dupc tinh nang
lien ket vdi mdy cdng cu
2 SO LU*OC VE KHA NANG BO CAC
CONTUOR 2D CUA MAY
Sud\ingV6 A (Visual Basic Application) trong Excel de viet chuomg trinh Add-in, kit qud xu ly nhu hinh 3
Nhu dd ndi d tren, mdy CMM 3D ma
chung tdi che tao dupc phdt trien tii mdt mdy
CMM 2D, do dd se ke thua dii lieu do dang 2D
Van de can gidi quyet la phdi xay dung dupc
m^t cong tur t$p hpp cdc dudng cong dd Trudc
tien, phai xu ly d& lifu do d d?ng 2D thu dupc
Cac tpa dp ndy, tao nen bien dang nhap
nhd, phdng to len se the hien nhu hinh 1
f 0.1122 0.0898
- i 1 - - ^
0.0752
Hmh I Bien dgng phdng 1^ bien dgng sau khi do dugc
Day Ichdng phai ia bien d ^ g th\rc t^ cua
dudng cong, svr nhSp nho nay li do phat xmig
khong dong bg cua 2 encoder vao thai diSm liy
mau da djnh trade Bi giai quy^t hi?n tuong
nay, c6 the thay cAc encoder co dp phan giai
cao hem Day lii each lam ton kem vi kinh tl va
khdng phat huy dugc vai tro ciia phAn mim tren
sdn phdm co di^n tur Thuong bien d^ng thuc
tS se nSm o giiia cac tpa dp ghi nhjta dupc DO
li?u diSm sau khi thu dupc se chuySn sang xii
iy bang cich ndi trung dilm ciia 2 do?n thang
kl nhau, qua Uinh cii IJp di IJp Iji nhu vay, cho
din khi CO dupc bien dang dii chinh xdc Voi
diJ li?u dam may nhu hinh 1, co thi mo ta chinh
xic cac bl m^t ky thujt ma khong cin npi suy
Hinh 2 Phuang phdp xirly dii ligu 2D do duge
tren may
tfinh 3 Bien dgng dd xd ly hodn thign v&i 1.000 vdng lgp (du&ng mdu dd)
De doi chiing dp chinh xae kit qui do, chiing toi da sii d^ng mpt duong miu chuin
da dupc xae nh|in tren mpt may CMM khac Can eii vio kha nSng phat hi?n dupc cac kich thuac chuan ciia dudng miu khi do tren may
ma chiing toi che tgo de ket luan:
- Ket qua do a vung xa goc miy sai so trung binh li 0.009 (mm);
- Kit qua do o vimg gin gdc miy cd sai s6 trung binh li 0.006 (mm)
Cic bien d^mg 2D d tren tilp tyc dupc xii ly dl t?io hinh mSt trong cic nghien eiiu duiSi day
3 XAY DVlVG Mi^T CONG 3D Mat cong li tjp hpp eiia nhilu dudiu sinh sip xlp theo mpt trjt tv, do dd ein thiet phii bd sung mpt bp trupt tryc Z dl djch chuyin
vj tri ciia vat miu (cat Idp)
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Hinh 4 Bo tri bdn trugt vd gd ddt ehi tiit can do
Trang 3Thvrc chdt m5i ldn do may se do cdc
bien dang 2D, nhung khi tdng hpp chung lai vdi
nhau vd cdch bdng mdt khodng cdch (zi-z^^ ,j)
giCra hai dudng thi se hinh thanh nen bl mat 3D
Can tim ra phucmg phdp sap xep chiing l^i vdi
nhau va t^o ra dupc cdc file phuc vu cho qud
trinh gia cdng
Budc 1: Sau khi do dupc bien d ^ g 2D,
tiln hdnh ldm min va chin tpa dp Z vdo cdt C
trong bdng tinh Excel bdng Add-in Quy udc vdi
lan do dau tien nh$p gid tri Id 0 (ung vdi tpa dp
Z=0) Nhung ldn do sau sS nhdp vao 0.25; 0.5; 1
tdy vdo ngudi dilu khien mudn do khoang each
giCta 2 dudng Id 0.25mm; 0.5mm hay 1mm Ket
qud ta thu dupc dO li^u xyz ciia cdc dudng sinh
OftnmTMHSOHM nCNDMn WT THE
M
Hinh 5 Kel qud cdc Iga dg sau khi ldm min
vd them tga dg Z
Budc 2: Sii dyng chiic nang lap trinh
giao di^n GUI B^ng Matlab 2007 dl vilt
phin mim tdng hpp vi v6 biSn djng 3D li
"SoHoa3D^Matlab" Thujt loan chuemg trinh
ve 3D vi kdt qui thu dupc nhu hinh dudi:
a^iaBcBmHalanfifc3D |
I Nlijin6itoiw t i n dign:
I Tm Tw) cic nc-ta (mt):
x ( i )
-«^) SbeaK:.!)
\ Hold
ffmh 6 Sadd thudt lodn vdphdn mem dgng mgt
eong 3D
Budc 3: Tiln hinh tao file va luu diJ lieu
d ^ g *.xyz, *.txt bang each ndi dai cac v6c-ta
x{i},y{i),z{i}) theo thir hf bing cdng cy
Vert-cat vi DImWrite trong Matlab2007
b(i} = [x{i}y{i}z{i}];
c = vertcat(b{:});
dlmwrite('pointcloud.xyz',c,'delimiter' ,',','newline',*pc');
Ddy Id dang file md bdng Notepad nen thudn tifin cho vific dua vdo cdc may CNC, hay
md bdng cdc chuomg trinh dd hpa nhu Solid-Works, Catia de chinh sira hodn thi$n bien dang
Htnh 7 M&file * xyz trong Solidworks vd bi mdt da chinh sua
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Trang 44 TINH CHQN BO PHAN GIAI ENCODER
Encoder li linh kipn dien tii co ban diing
tren may do cua ehilng tdi, no quyet djnh khi
nang phan bi^t cic djch chuyin nhd ciia may
Do vjy, trong qui trinh thilt ke phii tinh toin
vi lya chpn dp phan giai phu hpp dim bio yeu
td kinh tl vi ky thu?t ciia miy Gii sii budc di
chuyin don vi ciia diu do dupc cho trade, can
xic djnh dp phan giii cua eic encoder trang bj
cho moi khdp
Hinh 8 Chuyin dpng v&i bu&c be nhdt aia ddu do giOa hai diim trong khdng gian
- Bai toin ngupc:
Tir h? phuong trinh dpng hpc cua robot
da xiy dyng dupc dudi d?ng:
+
Vdi n li s6 tpa d5 suy rpng du dl xic
djnh vj tri vi hudng ciia khau cuoi
Gpi vj tri hi?n t?i dilm dang xit trong
viing lim vi^e (khdng gian cdng tic) eua tay do
li: (2)
Chpn tryc c6 dp phan giii nhd hon trong hai tryc X va Y ciia may de tinh ra budc
di chuyin be nhit cua diu do theo hinSng bit ky
mi may cin nhjn bilt, tren ca sd dd tinh la tpa
dp eiia dilm tilp theo diu do sS di chuyin dio trong vung lim vifc:
(5)
Hay:P,»
p^ + dx Piy+dy p^+dz
(6)
Tiong do:
(x,, yp z,) md ta vj tri khau tic dpng cudi;
(a, p,, Y,) md ti hudng khau tic dpng cudi
Gii trj chi thj ciia encoder cho trang thai
niy dupe tim tliiy tir v i ^ giii h? phucmg trinh
sau:
Tpa dp nay khi cjp nh$t vio (3) se nhjn dupc gii trj chi thj ciia eic encoder:
= («.« ? (7)
Nhu vfly, moi encoder di thyc hi^n mOt
di chuyin li:
Gii su pi trong khdng gian khdp t?i
tr^ng thii hifn thdi do dupc bdi cic encoder:
Gpi n li dp phan giii (n li so xung/1 vdng quay), n dupc xic djnh tii bat phuong trlnh:
(9)
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Trang 5NGHIEN CLfU-TRAO D O I
Sau khi tfnh ra n vd tham khdo cdc lo^
cdm bien tir nha sdn xudt dfi chpn lo^ encoder cd
dp phdn gidi ldn hon gid tri tinh dupc £)di vdi
v i ^ gidi quyfit d$ng hpc bdi todn tren, cdn md
hinh hda cdu hinh thuc tl ctJa thifit bj vd tinh todn
trfin Iy thuyet Xet robot 3 khau nhu hinh 10
Bdng 2: Ket qud tinh todn encoder
Hinh 9 So do dpng hpc tay do du&i dgng 3D
Ma t i ^ Tj cd d ^ g nhu sau:
1(10)
Sur dyng phuong phdp sd [5,11,12] dfi
xdc djnh cac bien khdp d^q^.q, Phucmg phdp
ndy sfi Idm b^c Id quan h$ di chuyfin nhd glQa
ngd vdo (d4u do) vd ngd ra (cdc encoder) thay
cho vi^c dung ma tr$n Jacobian truyen thdng
Tren ca sd do tfnh todn dupc d0 phdn gidi cua
encoder cho tiing khdp Gid sur sai sd do md td
bdi m^t cku cd dudng kfnh Id 0.06 mm vd sd
difim khdo sdt Id 1,2,3.4,5,6
dl(max-imn) 0.059999844
jj2(max-niin)_, ^3(mfK-inin) 0.000400813
i)d phin giii 15668.14545
0.000325663
^DpP&giii 19283.73223
Hinh 10: Xe djch trong phgmvi cho ph^ cda ddu do
Nfiu ldy dp di ddng tvr do cua tdm bdn tay khdng qua mdt m$t cdu dudng kfnh 0.06 (mm), cdn su dung hai encoder cd sd xung dd ldm trdn Ifin khodng 20.000 (xung/vdng) Tfnh dfin cd vi^c nhan xung 4 ldn trong bdn thilt kfi ndy, chung tdi chpn hai encoder 5.000 (xung/ vdng), model E40S6 - 5000 - 3 - 24 ciia Autonic Ddng thdi, vdi lupng dich chuyfin dl
= 0.059999844, ta hoan todn tfnh chpn dupc bO tnrpt vft-me bi vd md-to dan dpng
5 Ktr L U ^
Vdi m\ic tifiu d$t ra Id thilt ke, che t^o
vd thir nghidm thifit b) sd hda bifin d ^ g 3D Chung tdi dd phdt trifin mpt phuang phdp thilt kfi ngupc tu dp chinh xdc bifit trudc cua phfip do gidn tilp tfnh ra d$ chfnh xdc cua cdc phfip do true tiep Bdi todn ngupc vfi dp chfnh xdc, trong
do ludng gidn tifip dupc gidi bdng phuong phdp
sd vdi d$ chinh xdc cao vd cd tinh tdng qudt
Cdc h^n chfi vfi phan cung ciia mdy do
da dupc bll l^i trfin phdn mem, phuang phdp tfnh todn dd ddm bdo dupc cd hai yfiu c4u Id tinh kinh tfi vd tinh ky thu$t Mdy chl tgo thdnh cdng da thu nghidm tinh ndng do cd d$ chfnh xdc tucmg duang vdi cdc mdy thuong mgi, phdn Cling vd phdn mem dang su d\mg ciing nhu
phuang phdp tinh todn hodn todn thfeh hpp dh
tgo ra cdc mdy cd dp chfnh xdc rit cao Difiu ndy, ciing dung khi sii dyng cdc cau triic song song ho$c cdc cdu true cd sd bgc t\r do ldn hem mdy thu n g h i ^ trong bdi bdo nay • =
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Ngdy nhan bdi: 05/7/2016
Ngdy phdn bifin: 18/8/2016
Tdi lifn tham khao:
[ 1 ] Mitutoyo Corporation, Linear Gage, "Dimension
sensors offering superb durability aruJ environmenlal
resistance suitable for in-line measurements"
Catalog No E4174-542/572/575
[2] Kosaka Labotory Ltd, "Contour Measuring
Instrument Formcoder EF650 Standard
Specifications", Specifications No E-0201ER2
[3] Wu.C.H "Robot Accuracy Analysis based
on Kinematics" IEEE Joumal of robotics and
Automation 2 1986
[4] Nguyen Thi$n Phuc; "Nghien cuu, thiet ke, che
tgo cdc robot thdng minh phuc vu cdc img dyng
quan trpng, nhdm sdn phdm robot RE"; Dfi tdi KC
03-08, Ha Noi, 2006
[5] Pham Thanh Long; "A New Method to Solve the
Reverse Kinematic Robot Problem", ISTS "Iliaiteiid,
2012
[6] Qiu Zurong, Shi Zhaoyao and Li Yan, "The Research of Machinery Manufacturing Measuremeta Technology" China Engineering Science, vol 12,
pp n-19,October,2010
[7] Wei Peng, Xuegang Wang, Bin Tang, and
Hongang Wu, "A novel analydcal method and error criterion of the synthetic range profile, IEEE Transl." vol 2, pp 1648-1651, October 2010
[8] Weckemnann A, Peggs G, Hofimann J, {2006)
"Probing systems for dimensional micro- and nano-metrology" Meas Sci Technol 17, 504-509 [9] Pham Thanh Long, Ly Thanh Minh; "Thiitki che tgo vd img dung mdy do PCMM kiiu robof Tap chi Ca khi Vi?t Nam, s6 11/2014
[10] Pham Thanh Long, Ly Thanh Minh, Bdo cfc tdng kit de tai nghien cmi khoa hpc co so, Tmdng Dai hpc KJ thudt C6ng nghi$p Thdi Nguyen, ni3
so T2014-16: "Thiit ki, che tgo vd thu nghipm may PCMM kiiu tay robof*, 2015
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