Research on Miniature Calibre Rail-Guns for the Mechanical Arm

Transcription

1 ICMAA 7 8, 55 (7) DOI:.5/ maecconf/7855 Reearch on Miniaure Calibre Rail-Gun for he Mechanical Arm Cao Ronggang, Zhang Guangwei and Su Ming Beijing Iniue of Technology5 Souh Zhongguancun Sree, Haidian Diric, Beijing, , China Abrac. Rail-gun hould no only be ued o miliary applicaion, bu alo can be developed a applicaion in he civilian apec of he marke. Wih he developmen of he elecromagneic launch echnology, baed on he imilariy heory, uing he exiing rail-gun model o guide he conrucion of more economical miniaure calibre rail-gun, and apply i in ome machinery and equipmen, hi idea will open up a wider rail-gun applicaion pace. Thi aricle will focu on he feaibiliy of applicaion of miniaure calibre rail-gun in he mechanical arm. Thi paper deign he chemaic diagram, hen heoreical analyze force condiion of he armaure in he mechanical arm, calculae he poible range of he curren ampliude and o on. The exiing rail-gun model can be ued o guide deign he circui diagram of he miniaure calibre rail-gun. Baed on he imilariy heory and many imulaion experimen, deigned he experimenal parameer of a miniaure rail-gun and analyzed he curren, Lorenz force, velociy, and locaion of he exiing rail-gun and miniaure rail-gun. The reul how hahe rail-gun launching echnology applied o robo arm i feaibiliy. The applicaion of miniaure calibre rail-gun in he mechanical arm will benefio he furher developmen of rail-gun. Nomenclaure Uc() = capacior volage, I() = circui curren, R R() L F() = equivalen iniial reior of circui, = rail reior, = equivalen iniial inducance of circui, = rail inducance, = back elecromoive force of armaure, = elecromagneic force, L = rail inducance gradien, m = armaure ma, a() = armaure acceleraion, = armaure drag force, v() = armaure velociy, x() = armaure diplacemen, v x U C = iniial velociy of he armaure, = reiance gradien of rail, = charging volage of he capacior, = capacior capaciance, w h = hick of he ub-cale rail-gun, = all of he ub-cale rail-gun, = long of he ub-cale rail-gun. Inroducion Elecromagneic launching echnology a a new launching echnology i a general echnology following he radiional chemical energy firing echnology. According o he principle i can be divided ino elecromagneic rail-gun and coil-gun. Elecromagneic rail-gun ha been exenively udied for many year. I principle and concep were pu forward in he lae 9h cenury. French miliary ha correponding heoreical exploraory reearch ahe beginning of h cenury. German miliary go financial aid o do he experimenal verificaion of principle during World War II. Be rericed by he indury ahaime and he proceing mean of baic indury uch a he maerial, American experienced a long-erm repeaed verificaion afer he Second War in world, and emporarily helved he reearch on miliary applicaion of elecromagneic launching echnology in 96. Unil he lae of 97, he reul of ucceful experimen of Marhall are publihed, hi new launching echnology re-enered he miliary reearch program. And in 98 ared a new wave of udy of rail-gun launching echnology []. Afer enering he 99, wih he developmen of rail-gun launching echnology o he The Auhor, publihed by EDP Science. Thi i an open acce aricle diribued under he erm of he Creaive Common Aribuion Licene 4. (hp://creaivecommon.org/licene/by/4./).

2 ICMAA 7 8, 55 (7) DOI:.5/ maecconf/7855 deph, miliary and many reearcher found ome eriou problem ha i i difficulo olve in horime on baic heorie and applicaion, uch a he problem of power upply and launcher life. From hi period o 7 or o, he main udy of elecromagneic launching echnology i olving key echnique. Elecromagneic gun oriened o miliary requiremen i mainly concenraed on rail-gun. In he recen year [], wih American navy imulaed rail-gun on a large cale elecromagneic launching echnology ha obained coniderable developmen, epecially elecromagneic launcher. By he iued lieraure we can ee hahe launcher life of rail-gun ha been baically olved. Recenly elecromagneic launching echnology i expeced o rapidly progre. Figure how he chemaic diagram of rail-gun. Figure. Schemaic diagram of rail-gun There are many kind of he ranmiion mechanim of miniaure manipulae a preen. They can be roughly divided ino elecric drive, preure drive, and inernal combuion engine drive. Moor drive i he common way of elecric drive, uch a aynchronou and ynchronou moor drive and epper moor drive. The uual form of preure drive i hydraulic or pneumaic acuaor. And inernal combuion engine drive generally ued micro inernal combuion engine. Rail-gun a he power mechanim of mechanical arm i belong o direc linear drive. The rucural of he radiional linear moor or elecron puher mainly are coil-gun or are finihed by he mechanical rucure of raigh line mechanim convered by roaing mechanim. The chemaic diagram of linear moor i hown in figure. Comparing wih roaing mechanim and coil-ype linear moor, he rail-gun ha he advanage of imple rucure and eay conrol while i applied o drive manipulaor. and manipulaor. Baed on deign and analyi of he manipulaor yem of micro caliber rail-gun, hi paper gained he appropriae elecric parameer by reearching and analyzing he characeriic, and heory analyzing he force condiion of armaure. Analyi he circui parameer of miniaure calibre rail-gun The orage energy of puled power upply yem of rail-gun could reach mega-joule, he lengh of he launcher could be up o everal meer, and he calibre of rail-gun wa uually everal en of millimeer. Wih one experimenal device a example, he parameer of he rail-gun i line in Table. For he elecromagneic force endured by armaure during he acceleraion i grea, he fricion force can be aumed o. Figure 3 how he rail-gun equivalen circui model of he yem [3] [4]. And figure 4 how he implified equivalen circui of rail-gun. Table. Railgun parameer Parameer Capaciance configuraion charge volage Rail lengh Armaure ma Pule-haping inducor Capacior reiance Inducor reiance Cable reiance Inducance gradien Reiance gradien Value mf 8KV 5 mm.kg 5μH mω mω mω/m.5μh/m.mω/m Figure. Schemaic diagram of linear moor Elecromagneic launching echnology i mainly driven by he miliary demand. The reearch focu and he hopo in currenudy are boh placed on miliary applicaion. The udy i developed from medium-mall caliber o large caliber. Thi paper mainly udie he deign and compuaion of he launching echnology of micro caliber rail-gun launcher and launch yem in he micro movable Figure 3. Rail-gun equivalen circui model configuraion I R Uc() R Figure 4. Simplified equivalen circui of rail-gun L The equivalen circui equaion may be wrien: + _

3 ICMAA 7 8, 55 (7) DOI:.5/ maecconf/7855 d Uc () E() R()+R I() (L()+L I() () d The elecromagneic force on armaure can be expreed a F () I() () The acceleraion equaion can be wrien a F () F ma () (3) z The armaure velociy v(), he armaure diplacemen x(), he rail reiance R(), and he rail inducance can be derived baed on he equaion ()~(3) v( ) v - I ( ) d m m (4) x () x v - I() dd m m (5) F x v d d m m z R( ) R' R' - I ( ) (6) L () Lx ' v - I() dd m m (7) For he back elecromoive force of armaure i proporional o he produc of magneic inducion ineniy and velociy, and he magneic inducion ineniy i proporional o circui curren, o he back elecromoive [5] [6] force of armaure can be wrien a E () I() v- I() d m m (8) Baed on he relaion of he charge of capacior, he volage of capacior can be wrien a Uc() U I() d (9) C MATLAB, which provide an inegraed environmen for dynamic yem modeling, imulaion and comprehenive analyi [7]. Baed on he modeling and analyi of elecric circui parameer, hi paper deduced he inegrae form of equaion (), and hen pued up a imulaion model of he circui. Figure 5 how he imulaion model. In Figure 5, L wa he pule-haping inducance of circui, Lb wa he iniial inducance in he rail, R wa he oal reiance in he capacior branch, Rb wa he iniial reiance in he rail. Figure 6 hown he imulaion reul, included he curren, velociy, and he locaion of armaure. In figure 6, he fir figure how hahe dicharge ime of he capacior wa ~.5 m, he peak curren wa ~.8 MA. The econd figure how hahe maximum Lorenz force of armaure wa abou.65*5n. The hird figure hown ha he velociy of armaure reached he maximum afer he capacior dicharged. The fourh figure hown hahere wa a acceleraion proce of armaure during he capacior dicharging, and hen he armaure wa moving wih uniform velociie in raigh line. The barrel reidence ime of armaure wa 4.8m. A hown in figure 6, he imulaion reul did decribe he experimenal daa quie well. Figure 6. The imulaion reul of railgun v i() v Subyem Inegraor 3 Inegraor Gain -K- U x Inegraor / i() v x Subyem4 L x5 Produc Inegraor / Figure 7. Srucure diagram of manipulaor x x i() v R() x Subyem3 R Figure 5. Simulaion model for he circui x4 Produc 3 The elecric circui imulaion of he rail-gun wa carried ou by uing Simulink. Simulink i a componen of 3 Deign of manipulaor yem baed on he elecromagneic launching echnology Rail-gun need exremely high pule curren, and make ric demand on he power upply. Conidering he miniaure caliber rail-gun doen need high muzzle velociy and acceleraion of armaure compared wih he rail-gun for 3

4 ICMAA 7 8, 55 (7) DOI:.5/ maecconf/7855 miliary requiremen, hi paper uing he enhanced rail-gun and he enhanced armaure of high field magne. Be rericed by he fuure applicaion requiremen of manipulaor, he mehod of connecing puled power upply wih he muzzle and he breech repecively i applied o realize he reciprocae moion of armaure. Figure 7 how he rucure diagram. And he yem diagram of manipulaor i hown in Figure 8. The inducance gradien wa derived a.5μh/m. I can be known by many imulaion ha increaing volage and capaciive value can improve he bearing enion force of he miniaure rail-gun when he hape and he maerial of he rail-gun were deermined. However, he overize volage would caue overize curren, and he overize capaciance would caue over lowing energy uilizaion raio. In hi paper he ub-cale yem conied of 5 capacior, he charging volage of capacior wa eo 8.9V, and he capaciance of capacior wa eo 5mf, he reiance of capacior wa.6mω. The reiance force of armaure wa aumed o be.3n in order o reach he purpoe hahe armaure could move o muzzle in.econd. 3. Simulaion analyi Figure 8. Syem diagram of manipulaor The imulaion reul of reiance force exiing in he ub-cale railgun wa hown in Figure 9, including he curren, he reulan force, he velociy, and he locaion of armaure. 3. Parameer Calculaion The drive yem baed on rail-gun ha he imple conrol mechanim and conrol Sraegy for i only need o conrol he firing ime, and don need o keep accurae iming conrol ju like linear moor and coil-gun. The manipulaor rucure which i uiable for he fuure engineering applicaion ued he mehod, which parallel many manipulaor wih redundancy conrol, o compleed differen exenion angle and diplacemen of manipulaor wih differen meauremen range. By he aemen a above, we can find ouhahe manipulaor yem wih micro rail-gun ha advanage of imple rucure and imple conrol. In order o udy he feaibiliy of he rail-gun launching echnology applied o robo arm, hi paper derived he ub-cale rail-gun parameer baed on he caling mehod [8]. We obained for ubcale a -mm-long, 8-mm quare-bore gun wih rail dimenion of 8mm*mm* mm. The caled launch package ma wa.8g, he armaure reiance wa 3mΩ. The reiance of conducor wa.4mω/m, and he value of he pule-haping inducor wa μh. Baed on he equaion R' R/ L / S he reiance gradien wa derived a.5mω/m. In he cae of high frequency magneic field diribuion he calculaion formula of he inducance gradien of he elecromagneic launcher wih a recangular aperure can be wrien a (( ln( F))ln(F )) () F 3.397( w/ h).663( w/ h)( / h) () F ( / h).9( w/ h).637( w/ h)( / h) () Figure 9. Simulaion reul of he ub-cale A hown in he figure 9, (he fir figure how he dicharge ime of he capacior, he econd figure how he reulan force of armaure, he hird figure how he velociy of armaure, he fourh figure how he locaion of armaure).he dicharge ime of he ub-cale rail-gun wa ~., he peak curren wa ~55A, he maximum reulan force of armaure wa ~.8N, when he reulan force reduced o N, he velociy of armaure reached he maximum, which wa.m/-, he muzzle ime of armaure wa.338, i alo he ime for he velociy reduced o m/-. In hi imulaion, he peak curren wa abou 55A, i wa ill grea and may caue unafe problem. While he enion force of he miniaure rail-gun wa oo mall. Increaing inducance gradien and curren can improve he bearing Lorenz force of armaure wa known by he equaion (), in hi way he enion force of he miniaure rail-gun can increaed. The inducance gradien can be increaed by a change of he rail geomeric parameer. 4

5 ICMAA 7 8, 55 (7) DOI:.5/ maecconf/ Concluion The heoreical analyi and he reul of imulaion how ha he rail-gun launching echnology applied o robo arm i feaibiliy. Buhe hape and he maerial of he miniaure rail-gun hould be change. For he armaure can eaily ge larger Lorenz force from coil-gun, change he rail-gun o coil-gun may can alo uiable. Acknowledgmen Thi work i uppored by he Naional Naural Science Foundaion of China under Gran 547. Reference. H. D. Fair. Progre in Elecromagneic Launch Science and Technology. IEEE Tran Magn. 43,,93-98, (7). H. D. Fair. Advance in Elecromagneic Launch Science and Technology and i Applicaion. IEEE Tran Magn. 44,, 5-3, (9) 3. N. Pan, X. J. Han. Elecromagneic Railgun Circui Simulaion Modeling. Ship Science and Technology. 35,, -5, (3) 4. P. Z. Liu, X. J. Yu, J. Li and S. Z. Li. Energy Converion Efficiency of Elecromagneic Launcher wih Capacior-baed Puled Power Syem. IEEE T Plama SCI. 4, 5, 95-99, (3) 5. G. Q. Chen, H. Y. Zhang, Y. H. Wang, X. L. Wei and C. Z. Fang. The Circui Theory Analyi and Dynamic Aimulaion for he Capacior Drived Railgun. Elecric Machine and Conrol.,, 3-6, ( 6) 6. G. Q. Chen, Y. H. Wang, X. L. Wei and H. Y. Zhang. Compuer Simulaion of Elecromagneic Proce in he Capacior Drive Rail gun. Tranacion of China Elecroechnical Sociey., 4, 68-7, (7) 7. J. Yao and S. H. Ma. Simulink Simulaion and Modeling. Xi an: Xidian Univeriy pre. (7) 8. L. W. Jin, J. Li and B. Lei. Approximae Field Scaling of Railgun Launcher Under he Condiion of Maching Projecile Dynamic Parameer. IEEE T Plama SCI. 43, 9, , (5) 5