instructions for use · machine tool instead of the cutting tool, which conibines the system of...
TRANSCRIPT
Instructions for use
Title Non-Contact Shape Measurement and Machining of Curved Three-Dimensional Objects
Author(s) Kishinami, Takeshi; Kawabata, Tooru; Koyama, Tadashi; Saito, Katsumasa
Citation 北海道大學工學部研究報告, 120, 1-12
Issue Date 1984-03-30
Doc URL http://hdl.handle.net/2115/41865
Type bulletin (article)
File Information 120_1-12.pdf
Hokkaido University Collection of Scholarly and Academic Papers : HUSCAP
北海道大掌工学部研究報告第120・署・ (日召抱59奪三)
Bulletin of the Faculty of Engineering,
Hokkaldo Universlty, No. !20 (1984)
Non-Contact Shape Measurement and MachiRiRg of
Curved Three-Dimensional Objects
Tal〈eshi 1〈is}一iiN,“,{i, Tooru KAwABA’rA, Tadashi KoyAtv,iA*
and
Katsumasa SAiTo
(Receivecl November 30, 1983)
Abstract
Utilizing a ranging system, consisting of a laser, TV-camera and N/C naachine
tool, three-dimensional images of curved three-dimensional objects were obtained.
The object was defined by many mesh point coordinate data w}一}ich were given by the
Iaser ranging system.
After measuring curved three-dimensional objects, the mesh point coordinate data
were transfered into the lnteractive IV{achining System, which consists of computer
and direct numerically contrelled machine tool, in an attempt to manufacture some
curved three-dimensional objects.
By using this system, we can easily and quick1y niachine curved three-dimensional
models from untouchable curved objects.
1. lntredllctieit
IN,laclaining of curved three-dimensional objects is a highly advanced new field. There
are some technical barriers, such as, how to define the shape of a curved three-dimensional
object and lriow to mac}aine the same automatically. Generally, in order to define t}’ie shape
of ctirved three-dimensional objects, we generally use mesh point da{a and interpolation
’formulas.
Mk ethods for accurality and readily obtaining mesh point data are now the most
important problems vvlaich must be solved by industry. A laser and TV camera non-
contact ranging system will be useful method for solving the above mentioned problem.
We have already developed the lnteractive Machining Systena for machining of curved
three-dimensional objects [1] . This system makes it easy for us to naachine some curved
three-dimensional objects, if the mesh point data are given.
This paper describes an experimental apparatus of a ranging system which consists of
laser, TV camera and N/C machine tool, which is located on the spindle head of N/C
machine tool instead of the cutting tool, which conibines the system of laser ranging system
and lnteractive Machining System. Lastly, some examples of ineasuring results and
machined objects are described.
Il)epartnient of Precision E..ng{neering, Factilty of 1.’,’.nginnering, 1…lol〈1{aido Unii,’ersity, Tixliishi一一8 1〈ita一一1.3
1〈ita-ku, Sapporo 060 Jat pan.
*II’oyocla Ko・一ki, Robot Divifien, Asahi-Enachi, Shintonii-cho, 1-1 Kariya一一shi, Aichl-1{en, Japan,
2 ’1’akeshi 1〈lsi-Ilx.’i/i g , ’1’ooru Ki“sJABArr,x , Tadashi Koyf・x:iix and Katsumasa SAI’ro 2
2. 1,aser Ranging System
The ranging system may be briefly described as a laser which projects a beam of light
on the object to be scanned, and a TV camera which detects the spot of laser light as it
illtnininates the curved objects. A calibration procedure detennines the relative position of
the laser with respect to the TV camera, so that, depth information may be derived from
the video iinage. Fig. 1 shows a general view of t.he apparatus of ranging and machining
systems.
VIOEO {EIA)
lls vs
MICRO CO図P雌TER APPしε一言1
VIOEO!tiTER-
FACE
IXO
団TER卿
FACE拳
soeiv
PLqGNET帽
SCALE
認賄 囎
擢ORX
N/C NILLING eutCleiE
興1飼Ico門PりTε艮
1;OVA 4fX (SHC)
H/C
ceriT-
ROLLER
RS-232C DNC幽しINE
Fig.1 Scheme of experimental g.ystem
Ranging information are so clearly relevant to the three-dimensional shape of objects
that many investigations of its use in scene analysis have by and large been ignored as to
the intensity of information. Thus Agin and Binford [2] , Nitzan, Brain and Duda [3」 ,
Shirai and Suwa [4] , and Sato and Fujita [5] have basically beeil concerned with various
ways亡。 describe objec亡s by fittillg sしIrfaces亡。 range data、 But these methods are based on
the fixed relative position of laser or light source, TV camera and objects.
The basic principle of the proposed method is the triangulation method which is well
known. By controlling the relative position of laser and object with N/C machine tool, the
coordinates of spots on the object are detected from the video image ftc r}d coordinate system
of N/C machine tool.
2-! Experimental Apparatus of Ranging System
The non-contact laser ranging system consists of laser, TV camera (SONY AVC一一 i500)
and micro-computc’sr (Apple ll). We use a helium-neon laser emitting about 5mXV of red
iight at wave length of 6328A・. Since, the laser tube is portable, so we can easily set it on
the spindle head of N/C machine tool. To simplify the calculation of a laser spot position
on an object, we use the fixed relative position between laser tube and TV camera on one
brac1くet(see Fi墓ユ),
The x, y coordinates are taken into the micro-coi’nputer from the scale counters of N/
C machine tool. And the z coordinate of a spot on an object is taken in via the video image
of TV camera.
2-2 Measuring IVIethod
The bracl〈et on which the laser tube and TV camera are fixed, is set on the spindle
head of N/C machine tool instead of the cutting tool. Measuring is’ done by moving tlae
3 N’on-Contact Shape ,TY{Eeasuren]ent anc} ,Ttilachiniiig of Curved ’1“hree-ll)ii’nensional Obj’ects 3
1aser ranging system with N/C machine t()ol over the surface of the object that is to be
measurecl.
Fig. 2 shows t}rie scheme of laser ranging system. X, Y and Z coerdinates are fixed as
shown in Fig..2. Ancl the partial coordinate systena on a target plane of TV camera is
called H-V coordinate on H-V plane.
z
x
TARGET PLANE OF CAMERA H
Hs
v
v
di
s D
.tg一一gx LENS XX ’一一一
s ix
L
ノ
/、ぐ
x
LASER TUBE
/ /へ ヘ ノ ラ
ヒ//^//’、 / // 〆/ //
ノ // //
//SCAVINING MOTI。N ノ/
\.
Zx. zgrbo
x
//ぐ一一
LAS[R
BEA隅
×/一
6BJEcf
/t
鷺’
fxNQZmax
/
Y
Fig.2 Scheme of laser ranging system
The distance ’from the lens center to laser beam is de’fined by D as shown in Fig. 2.
The angle between laser beam axis and the lens center axis of TV canaera is defined by 0.
fis the distance froln the center of the lens to the target plane(正一1-V plane>. Hs, Vs are
the coordinates of the laser spot image on an 1’1-V plane.
”1’he laser beam is set vex”tical to Y一一Y plane, and the ”1“V camera is set at a position
D distance away from the laser beam at an ang. le 0 as the laser beam axis. The origtn on
I/1-V plane ef TV camera is t}’}一e point where tlae electron beam begins its scan; the
direction of scanning is plus coordinate direction.
9uring the measuring operation, the position of the laser spot changes H coordinate
about on H-V plane, because the relative position o’f laser tube and TV camera is fixecl,
emd the laser spot on the object m.()ves on the plane x・xrhich involves the laser beam axis and
Iens center a>.cis. The clistance Zd between the laser spot position on the object and the
cross point of laser beam axis and lens cent.er axis, as shown in Fig. 3, is given by the
ecluation (D.
D Zd嵩 (1) tan(6}一{p)
where,
(p ==tan”i [!l’IL{21}lt!.Sl..1’IST}’IO ]
1’lo: 1’1 coordinate o’f the lens center axis on 1”1-V plane.
’1“hen, Z coordinate of the spot on the object is given by equation (2).
4 Takeshi K{sH{Nt“ti , Tooru Kt“.xJ・ABA’rA , Tadashi KoyA:・tA and Katsumasa SAiTo 4
遭 ・
丁ARGET PLANEOF TV-CA}IERA
K1)>i>,
N
LErls
/
/’
/
x
v
x
D
×. e
xx(1.
一「、,
N
Z
zo LN
LASgRTUB[
LASERBEAM
Zmax
SPOT
GB認Cτ
““ × ×’×’x
x
Fig. 3 Geometrical Rerationship among Laser, TV and Object
Z=Zo-Zd (2)where, Zo is the distance from Y-Y plane to the cross point of laser axis and lens center
axis.
2一一3 Hardware
In order to ebtain the position of the laser spot image, as quickly as possible hardware
circuit which consists of three main circuits, that are, a syncronizing separator circuit to
separate the horizontal and vertical syncronizing signals of the video signal, counter circuit
for detecting the spot position, and trigger circuit for recognition of the spike pulse which
is given by the spot image on the target plane of TV camera.
The video output signal was obtained by scanning the target plane of TV camera, and
sent to the special hardware circuit. Fig. 4 shows an example of the vdieo output signal.
The first wide downward pulse is the vertical syncronizing pulse. This vertical
syncronizing pulse is the beginning signal of a screen data. The next narrow down-ward
pulse is the horizontal syncronizing pulse wlaich is the beginning of one horizontal line in
a screen.
The spike pulse between two horizontal syncronizing pulses corresponds to the
boundary of spot image on target plane. By watching and averaging a number of spike
pulses on some horizontal lines, we can estimate the position of laser spot image on the
target plane. ln Fig. 4, the position of the spot image on H-V coordinate corresponds to
the time Tvs and Ths on video signal. ln order to detect the time Tvs and Ths, the interval
time Tv and Th between vertical syncronizing pulses and horizontal syncronizing pulses
respectively are divided into 256 small interval times with an 8 bit counter, and the special
hardware circuit has a function to start and stop the Tv counter and Th counter by
detecting the syncronizing pu}se and spike pulse.
In the Th counter, by watching the contents of Th counter when detecting the spike
5 Non-Contact Shape ?,t・’leasurement and r,Y’lac}iining. of Curx,ed Three-Dimens. ional Objects. 5
TARSET戸酬E OF[N,E凧
茄
VOLTASE5〔Tvs
THS
S円KE
VERT@SY「κ@ 簡LSE
HO臼rY卜犀C-PULSE
T}1
了〉
τ既
Fig.4 Video Signal
pulse, xve can easily know the horizontal position of spot on the screen. On the other hancl,
in the ’1’s,T cotmter, b>r counting how nmtai’iy horizontal syncronizing pulses have passed until
detecting the spil〈e pulse, we can easily know the vertical positioii of spot image on the
target plane o/f TV caniera.
For detecting the spil〈e pulse, we prepared a trigger circuit which niakes a spike pulse
if the brightness of a spot image is ever the threshold level. And this spike pulse also plays
a role for data ready flag. When the data ready flag is recelved at the micro-computer,
the contents of Th and Ty counters are sent fed to the inicro-computer. Fig. 5 shows the
b}ock diagram of the special hardwd’ re circuit which was used in this system.
Vfidee signal
Vertica峯&HDrizo員騨
tsl,synchroniling・
内照1separatorcircuit
t
i
E
tt
t
L
t
t
t
I
lI
t
t
I
I覧
Ertable
Oscilater
(4MHz)
Vertical syfitchronizingsigeal sepa.
rator Circuit
Re$et Start
TH-Counter (8bits)
一一’ @一 s N
l
l
t
i VeレtIC凸1 synchro角~zing
1 signal
丁rigger circロit
fer
Reeagnition of
spike pulse
D唱fl蓬p-flop Clo¢k
Q
01234567 Ror. DateCHs)
Reset Start
Tv-Counter {8bits}
D-flip-flop Clock
Q.
el 234 S 67 Vert. DataCVs)
t
t
1
1
1
1
1
1
1ノ
.Data $et ready
Fig.5 Block diagra}n o’f 1’larclware circuit
The i’nicro-computer(Apple II) has 48 1〈bytes of mei’nory that are free for use, a printer,
mini-floppy (140 kbytes) disk and CRT. ’1“he interface that connects the ranging system
6 Takeshi Kis}“N,xMi , ToorLt Kix“’fxB,・x’i’ix , Tadashi 1.〈oN’,x:i,N ancl Katsttmasa E.3t,,i’ro 6
and micro-computer contains a decocler circuit to decode the acldres. g. of the niicro-
computer. By・ using a data bus and an address btis and read/xvrite signal, the rangtng
systeni and niicro-coniputer sencl and receive data betw・een each other.
The mici”o-computer is also connected to X, “¥’ coordinate scales o’f N/C machine tool.
If the inicro-coinputer desires tlae X, Y coordinates, it inust first send a hold signal to the
scale controller to lock the scale buffers, at the second, the micro-computer reads the
contents of scalle buffers to obtain the X, Y coordinates. After the coordinates are read,
the micro-computer then sends a release signal to the scale controller.
2-4 Software
The software of a ranging system consists of three parts. The first part play・s the role
of obtaining the coordinate information from N/C machine to()1 and laser ranging. system.
The second part is the softxvare to calculate the Z coordinate from the input o’f laser
ranging system. The third part is the so’ftware that sends the necessary data to the
Interactive Machining Sy・stem for machining the object shape.
We will ei plain each part in detail. The ’first part is written by MC-6502
ASSE)IVIBLER to maintain high speed processing, , because the ranging system sends one
screen information every 1/60 second. The micro-computer sends a start signal to the
ranging system, then the micro-computer waits for the data ready signal to come from the
ranging system. The micro-computer receives certain spot point information from t}Jke
ranging system for one screen. By averaging the point coordinates, the center coordinate
of laser spot is calculatecl in the micro-computer. At the same time, the micr()一computer
gets the X, Y coordinates from the N/C machine tool.
2-5 Data Structure
The rectuired clata structure for the lnteractive iMachining System must be a mesh
array structure in topological space. The most simple way of gettlng inesh point data of
objects is by continuously moving a N/C naachine tool unde1一 the scanning mode “on the X
・一 x plane, to satisfly the restriction. ln order to do so, when the difference dX and dY
regarding the X-coordinate and Y-coordinate, exceed a certain fixed value, the holding
signal is transmitted to Xl, Y coordinate scale buffers, ancl the contents of X and Y scale
buffers are read by a micro-conaputer. At the same time, the Z coordinate is also read by
a mlcro-computer.
Each coordinate data for one mesh point, consists of eight bytes in length, as show in
Fig. 6. The first byte is used to iildicate the end of data record.
Normally this byte is zero, bttt at the last data, it is set to FF in
hexadecimal. The second and third bytes indicate the row and
column ・number of mesh array, The fourth and ’fifth bytes are for
the X coordinate in binary. The sixth and seventh bytes indicate
the Y coordinate in binary. The last byte is the Z coordinate.
The Z coordinate is directly stored from the ranging system,
When the N/C machine tool g.tops moving for more than 2
seconds, the micro-coinputer automatically judges the end of
measuring operation and stores the data on the mini-floppy disk.
The second part of software takes the data from the disk Fig.6 Data structure for
and transfers binary data to decimal data and the true Z ranging system
f!ag(000r Fl:つ
ドQW num丘.)er
CQIu駐m nurl毛ber
x-cOoごdlnaしe
@(bi照ry)
y-CQQrdinaしe
ibinary)
Z-coordinaしe
7 1iNj’on-Contact Shape ),,leasurenient ancl 1 ・’lachining og Curvecl ”1’hree-1)iniensionat Objects 7
coordinate value is ’calculated by the caliburation niethod shown below. ”1’he second part
is written in BASIC language and has t’ ?e ability to display the data on CR’1’ in a three
dimensionally graphic mode, and to calculate the normal vector on each mesh point.
Accorcling to Coons’ patch interpolation, we can completely define the curvecl patch
shape “,ith four corner points coordinates, 8 tangent vectors and 4 twist vectors by equation
(3).
Q (u, v) == [FO, Fl, Ge, Gl] ,.,.., [B] [FO, Fl, GO, Gl] Lu一. (3)
where,
[B] =:
QOO
QIO
Queo
QulO
Qe/
Qll
QuO!
Qu//
Qvoo
QvlO
Quveo
Quvlo
QvOl
Qvll
QuvOl
Quvl!
[Fe, Fl, Ge, Gl] = [t3, t2, t, 1] 2
-3
0
1
2 1 1
3 一2 一1
0 ! 0
0 0 e
Qij
Quij
Qvij
Quvij
: point (i, j) coordinate vector
: u一一directioll tallgellt vectol’ ol/ poil/t (i, j)
; v-direction tangent vector on point (i, j)
: twist vector on point (i, j)
If at i :O, !/3, 2/3,1, j ::: O, !/3, 2/3, 1, point coordii/tate vectiors are kno“tn, v¥e can easily
derive the eqtiation (4) from equatioil (3).
[B]= [F]買『E[D〕 [FTユー匿 (4)
1,Krhere,
[F] =z
FO (O)
FO (1/3)
FO (2/3)
FO (1)
Fl (O)
Fl (1/3)
Fl (2/3)
F! (1)
Go (e)
GO (1/3)
GO (2/3)
GO (1>
G/ (e)
Gl (1/3)
Gl (2/3)
Gl (1)
Q(O, e) Q(O, 1/3) Q(e, 2/3>
[E}] == 1 Q (!/3, e) Q (1/3, 1/3) Q (1/3, 2/3)
Q (2/3, e) Q (2/3, 1/3) Q (2/3, 2/3)
Q(1, O) Q(1, 1/3) Q(!, 2/3)
And normal vector is defined by equation (J’).
N (i, j) == Qu (i, j) × Qv (i, j)
Q (O, 1)
Q(1/3, 1)
Q (2/3, 1)
Q(1, 1)
(5)
8 「Fakes}}i正くls夏.1{NiXI II,「1、()oru 正《Aw、・、BATA,
At the final stage, the third part of the
softxvare plays the role of sending this
calculatecl data to the lnteractiver,v’lachining System through the RS-232C
general purpose interface. To avoid
tric nsmitting error, we use a hand shal〈e
communication niethod. The mini-computer receives a]] data from micro-
computer, rearranges the data to required
data structure of the lnteractive Machining
System as shown in Fig.7. After doing
these operations, it is possible to draw the
shape on the graphic display and to
machine the object shape by additing the
cutting. conditions in the lnteractive
Machining Systeiin. Fig. 8 shows the block
diagram of non-contact measuring and
machining system for curved three-
dimensional objects.
SPOT IMAGE
MachineToe]
motion
Tadashl K(:)}’AIIA and Kaζsumasa SAH・0 8
[塑蛮璽翼
1 . I l I
l i
E l 「 E
一一一一膳 一㎝}一丁一一酬需一一一「 lA仁rinite l Idata l
』一 一『一「
}
}
1
I
l
i . l i i
l } 1 ’ 1 コ 1 】 1 . l l . 1
} ・ 1 { . i
I i i l
l
I
}
I l l l
l l
I l
l l L牌_______________」
Fig.7 Data structure for Interactive
i>lachinil/g System
N血【oピ?5h size きめ㎜ユVeG』or
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cCOBvert 卜{s,Vs,X,Y,Z
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boordinate X,y,Z
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o Rearra倉9てng inpu宅
@ Data
B!nteractive@ 阿achining System@ Software
EDirect Numerical@ Control
BTRx
xRS232C
「}4AGNE
rCALE
Y
1湾terfacey
Zz
Fig. 8 Block Diagram of Non-Contact Measuring and Machining Syg. tem for curved object
3. lnteractive Machining System
When the required curved three-dimensional object is given by the mesh point data
which consists of a large set of point vectors and surface normal vectors from the laser
ranging systei’n, a perfect expression of curved object and.offset curved surface which is
needed for generating the cutter path, are constructed in mini一一computer by using Coons’
patch interpolation.
In case of machining of curved three-dimensional objects by using N/C mil}ing
machine and ball-end mill, the center of ball nose of ball-end mill must be on the r (radius
of cutter) 一〇ffset curved surface (so-called tool surface) against the required curved surface
9
x
NTon-Contact Shape r.Y,ieasurenient and .ry,lachining of Curved ’1’hree-1])iineng. ional Objects
//
x x.
autterpath
〆ピー
N ‘“N
x
x
x一
x
v\こ
s
〈.tool
xpm
ノ ’!
x
¥1
surface
xx
xx
〈=
u
requ三redsurface
x x x x
1
Fig.9
(v>r
琶
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ロ
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fLrLi
2 3
cutter peth mode
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言
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のε
虻
β
“
cvtter path
generating
processor
4
iR parametric space {u.v)
Representation of three-cllniensionak sur’face
xvith niesh point data and cutter path naodes.
prepar轟tio纏
procttssor for
蹴曇5め point d盈t轟
9
v
v
u
ズD.t.la,」~に幽
夙ゾLz覧’tt):’t
t.yi.f,11ik’
式鑑2.1’;」~虻
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Co◎口sl
pntch
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x
z
ε舅
ロ
ニ
ξ
睾
1?ig. 10 Basic strticture of lnteractixre
Machining System.
lis(BIT)
t’
.t’一t
’
(t・IM)
5娠o
IOO
50
e
1’
働
11
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ノ1
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’
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,ノ
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一
・ノ/
.t
ノφ’
i一
一i
-一t
t一一
一tρド
t一’
o 20 40 6e ZD (卜猶)
Setting Z-distance
Caribration Curve
80
13,0
i2,e
F韮9.ll
..⊥毛・
lI
R鴬V. AROUND 》二需AXIS
-XK
ZD
9
t
謄茎一丁一一rfエ”
一紛 一“e
一20 O 20 Surface englff
な0 ee e(DEG)
(陥>
!oo v喬1、0 &
馨
o 岳壕)lo
塞
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ゆ .f 59,0
9 歪
王Il
I
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1
1
REV. A鼠OUND Y酬汽X王S
e
}
一ee
Flg. 12
一tio 一2e e 20 lto ee e(DEG) Surface angle
Influence of g. t!rface angle on the
measurmg accuracy
10 Takeshi KisHiNAMi , Tooru KAwABATA , Tada$hi KOyAMA and Katsumasa SAiTo 10
as shown in Fig. 9. ln order to make it easy to input the cutting conditions to lnteractive
Machining System, we prepared four typical cutting mGdes for deciding the cutter paths
(mode-1, 2, 3 and 4). These cutting modes are generated in parametric space to move along
the constant parametor lines. And generated parametric cutting mode is converted to the
real cutter path in a physical space.
In addition to these selections, we prepared some interactive input method concerning
pick-feed, cut.ting direction and start point for an lnteractive Machining System as shown
in Fig. 10. By combining the selection of radius of the ball end mill, cutting mode, cutting
direction, start point and pick-feed, we can carry out machining of curved three-
dimensional object from rough cutting to finished cutting for the given mesh point data at
the machining operation.
4. Results of Experiment
4-1 Calibration and Measuring Accuracy
Accordjng to some non-linear factors of laser ranging system, it is difficultto get the
true Z distance by using only the calibration equation (1). Fig. 11 shows the relation
between the data given by TV camera and the actual Z coordinate. ln order to get an
estimation of Z distance of laser spot on the object, we use the curve of Fig. 11 as a
Fig. 13 Measuring results for half ball bocly.
z
o
o : MEASURED POINT BY RANGING SYS’TEM
e o e o
o
oj
50R
×Xx,
一50
IOo o
oe
q
ERROR SCALE
Ii’o ’mtm
o
o
o
50
Cm/m)
Y
Fig. 14 Measuring result on sectional plane of half ball body
1ユ Non-Contact Shape Measurement and Machining of Curved Three-Dimensional Objects 11
calibration curve. Some typical points of the calibration curve were stored in micro-
computer memory, and linear interpolation was applied between points to estimate the Z
coordinate.
To inspect the influence of surface angle of object to be measured, other experiments
were done with rotary index and flat plate. The small flat plate was set on the center axis
of rotary index, laser beam was emitted just across the rotational axis of rotary index, and
the laser spot on flat plate was monitored by TV camera. Fig. 12 shows the influence of
surface angle on the measuring accuracy. One is the experimental result frQm the direction
which is perpendicular to the plane involving the laser beam and center axis of TV camera,
and another is in parallel with it. From these results, an accuracy of spot detection is about
O.5 mm and the influence of surface angle on measuring accuracy is about O.7 mm for the
angle range from 一60’] to 十60e and the ranging distance 100 mm. Thus the influence of
surface angle on the measuring accuracy is not so clear.
And also in order to inspect the meas.uring accuracy of the laser ranging system, we
do the measuring experiment for a half-ball body. Fig. 13 show$. the results of measuring
a half-ball, which is represented by micro-computer (Apple II) screen plotting. And Fig. 14
also shows the measuring results of laser ranging system on sectional plane of half-ball
body. The solid line is the actual data and small circles are the data taken by the ranging
system. The error is less than O.7 mm for 100 mm ranging distance.
Fig. 15 Example of curved obj.ect. Fig. 16 Mea$uring result of pulsator.
Fig. 18 Machining example.
Fig. 17 Generated cutter path in lnteractive
Machining System
12 Takeshi Kig. HiNApt{i , Tooru Ktx“rABA’rA , Tadashi KoyA.ty,{A and Katsumasa SAi’ro 12
4-2
pulsator of washing machine, car body and etc.)
mspectlon
sometimes copied to metal material tising tracer controlled machine tools.
If we can make a plot-typed model by tising non-contact measuring technique aild N/
C machine tool, the primary model can be made from more softer inaterial (for example,
wax and etc.), and it is possible to save the required time of developement. ln order to do
so, we developed a laser ranging system with combined lnteractive Machining System.
And we applied it to measuring and machining of a pulsator of a washing machine as a
curved three-dimensional object (see Fig. 15).
Fig. 16 shows the measuring results of the part of pulsator whiclt is given by the
deve}oped laser ranging system. This data is sent to the lnteractive Machining System to
machine the shape of the pulsator. Fig.17 shows the generated cutter path in the
Interactive Machining System and Fig. 18 shows the machining example of the pulsator.
Measuring and Machining Results of a Curved Object
On the deve}opment of some new functional parts (for instance, shape of turbine blade,
, some plot-typed models were required for
ion of shapes. ln this case, the primary model was made by hand work and
5. Conclusion
In this paper, we have proposed an effective non-contact meaE uring system which is
combined with the lnteractive IVIachining System for measuring and machfning o’f curved
three-dirnensional objects. The features of this system are as follows:
1)
2)
3)
It is possible to rneasure some curved three-dimensional object very quickly with an
error of less than O.5 mm for a ranging distance 100 mm.
The rneasuring accuracy can be improved by increasing the capacity of counter and
centrelliRg the stability of saw tooth wave of TV camera with special hardware, and
by decreasing the size of laser spot.
By combining the laser ranging system and the lnteractive Machining System, xve can
easily machine some curved three-dimensional objects.
Refference
1)
2)
3)
4)
5)
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