CUTTING METHODS AND CARTESIAN ROBOTS KESME YÖNTEMLERİ VE KARTEZYEN ROBOTLAR

Transcription

1 ournal of Naval Scinc and Enginring 2009, Vol. 5, No.2, pp CUTTING METHODS AND CARTESIAN ROBOTS Asst. Prof. Ugur SIMSIR, Lt.Cdr. Turkish Naval Acady Mchanical Enginring Dpartnt Tuzla, Istanbul,Turkiy Abstract Th ain principal of cutting any atrial with a cartsian robot is trajctory following. Th cutting thod ust b copatibl with a cartsian robot. Gnrally 4 diffrnt ways of cutting thods ar prfrrd with cartsian robots. Ths ways ar oxign cutting, plasa cutting, lasr cutting and watrjt cutting. Watrjt cutting is th ost populr bcaus it provids cold cutting and it dosn t caus any dforation on spcially tals and on th othr hand it can cut all atrial. In this study, dsigning of a cartsian robot copatibl watrjt cutting is xplaind. KESME YÖNTEMLERİ VE KARTEZYEN ROBOTLAR Öztç Hrhangi bir alzyi kartzyn robot il ksnin ana prnsibi yörüng takibidir. Ks yönti kartzyn robot il çalışabilck uyuda olalıdır. Gnllikl kartzyn robotlar il 4 farklı ks yönti kullanılır. Bunlar, oksijn ks, plaza ks, lazr ks v sujti ks yöntlridir. Sujti ks yönti soğuk ks sağladığından, tallrd ısı girdisi oluşturadığı v dforasyona ndn oladığı v tü alzlr uygulanabildiği için n kullanışlı olanıdır. Bu çalışada sujti ks yönti il uyulu kartzyn robot dizaynı anlatılıştır. Kywords : cartsian, robot, cutting Anahtar Klilr : kartzyn, robot, ks 35

2 Cutting Mthods and Cartsian Robots 1. OPERATION PRINCIPLE OF CARTESIAN CUTTING ROBOT Cartsian robots follow two dinsional trajctory shaps drawn by using any 2D softwar ar transfrrd to DXF cods and DXF cods ar th initial conditions for th ain softwar. Th ain softwar includs all of th chanical and dynaical spcifications which blongs to syst. Th ain softwar provids driving th AC srvootors and uss PD control algorith to control vlocity and position of th cutting had. Cartsian robot dinsions can b any according to rqust of plant. Th cutting spd varis dpnding on th thicknss and atrial. Mchanical coponnts lik linr guids, ball baring, rack and pinion, lctrical otors and rduction gars according to rqustd vlocity of achin. Any closd shaps can b drawn by using LINE and ARC coands only. Thrfor two sparat following trajctory softwar wr prpard for LINE and ARC cutting. DXF fil of th gotry is dcodd and writtn in a fil. In this fil, LINES and ARCS ar rprsntd by diffrnt cods. By using ths cods, th ain softwar dcids to call ithr LINE or ARC trajctory following softwar. So sipl basic gotric shaps, such as circls, squars and rctangls, can b cut without drawing th. Th paratrs dfining ths shaps can b input to th softwar in nurical forat dirctly. Th ovnt of th cutting had is ralisd through ball scrw, rduction gar, rack-pinion syst and AC srvootors. Th trajctory following is th ain probl in th syst dsign. Position and vlocity control of th cutting had should b in axiu accuracy. In ordr to incras th position accuracy ball scrws and ball rail syst was slctd in this syst. Th advantags of th ball scrw ovr th ac scrw driv ar : 36

3 Ugur SIMSIR a. Th chanical fficincy of an ac scrw driv is a axiu of %50, whras a ball scrw can rach a chanical fficincy of up to %98 b. Highr lif xpctancy du to ngligibl war during opration c. Lss driv powr rquird d. No stick - slip ffct. Mor prcis positioning f. Highr travl spd g. Lss hat up Th ball rail syst with slf aligning fatur autoatically copnsats for rrors in alignnt up to 10 of arc with no rduction in load carrying capacity. Th positioning of th cutting had is an iportant stp on th way to fully autoatic cutting. For th running of autoatic production procsss a nubr of paratrs ar stord in th nurical control as achin constants. Th achin s zro point and th achin s fixd point ar norally idntical. Rlativ X and Y coordinats will b givn for that rfrnc point and togthr with th dfind working ara. Th zro point dfind to th softwar is usually th point at which all autoatic procsss start. All cutting procsss will b autoatically controlld, and onitord within th prograd working ara. 2. CUTTING METHODS Gnrally four cutting thods Plasa, Lasr, Oxign and Watrjt ar prfrrd in Industry and usd with Cartsian cutting robots. First thr hot cutting thods burn atrial and caus so distorsions and 37

4 Cutting Mthods and Cartsian Robots dflctions on atrial but watrjt cutting tchnology provids a cold cutting. Watrjt cutting is th nwst tchnology and it provids copltly cold procssing. In addd, all atrial can b cut with this tchnology. In this study watrjt cutting is considrd on cutting had of cartsian robots. 3. TRAECTORY FOLLOWING CONTROL ALGORITHM Syst : Th Loads drivn with AC srvootor. ( 1 ) :. + B. +M d = M d = k.u Stat spac quation: x 1 = ( 2 ) x 2 = ( 3 ) x 1 = x 2 ( 4 ) x B 1 k. x. M d. u ( 5 ) 2 2 x 1 (0) = 0; x 2 (0) = 0 38

5 Ugur SIMSIR x x B 0 j. x1 x k. u M d ( 6 ) Transfr function of th syst: X = A.X + B.U +C.W ( 7 ) Control typ : PD; u = K p ( rf - x1 ) - K v ( rf - x2 ); ( 8 ) rf K. p. k 2 ( 9 ). s B. s k. K. s K. k v p K p 2. 0 k ( 10 ) K v k B ( 11 ) X axis otor: Fnx 1 : x 1 = x 2 ; Fnx 2 : x B 2 2. x u k x. ( 12 ) Y axis otor: Fny 1 : y 1 = y 2 ; Fny 2 : y B 2 2. y u k y. ( 13 ) 39

6 Cutting Mthods and Cartsian Robots 4. BLOCK DIAGRAM OF THE SYSTEM 4.1. Arc block diagra - rf K p k / ( s + B ) 1 / s + + / k s K v B / k rf + 40

7 Ugur SIMSIR Figur 1: Arc Block diagra 4.2. Lin Block Diagra - rf K p k / ( s + B ) 1 / s + K v rf + 41

8 Cutting Mthods and Cartsian Robots Figur 2: Lin block diagra 5. CONCLUSION Watrjt cutting thod is prfrrd and applid with cartsian robots du to its any advantags. Th ain advantag of watrjt cutting thod is applying to all atrial. In addd, th thod is propr for trajctory following with cartsian robots, asy cutting had application on bridg and asy opration. And th othr advantags of watrjt cutting thod, it dosn t caus any thral ffct and dforation on tallic atrial. Watrjt cutting achins substitut rapidly othr thral cutting thods lik oxygn, plasa and lasr cutting thods for spcially tallic atrial. REFERENCES [1] WALLOWICH, W.A, 1986, Robotics, Basic analysis and dsign, Brown Univrsity [2] OGATA, K., 2002, Modrn Control Enginring, Prntic Hall [3] DOTE, Y., KINOSHITA, S., 1990, Brushlss srvootors fundantals and application, OXFORD, 1990 [4] OZOKLAV, H., 1986, Kinatik, Çağlayan Kitabvi Istanbul [5] SIMSIR, U., 1997, Autocad Yardııyla Çalışan Kartzyn Sac Ks Robotu, Yüksk Lisans Tzi, Istanbul tknik Ünivrsitsi, Fn Bililri Enstitüsü [6] 42