Proceedings of the 25th Chinese Control Conference 7-11 August, 2006, Harbin, Heilongjiang it ltStv'icsek+Pb m I'4"f + t TVWWKiZ1 , IY,> 100080 E-mail: Lguo@iss.ac.cn : *t:t ffAZ_f 2Jt_fVicsekf'TfOt, 2offl ffX W % tRbA' T,l AM Me8&< 9 7;ZZ i hi 1t1 bt < tK4- Fp ol Ah -/\- TA)~ H-1 P)T_ )A1f jff: $+8>T,WT Jf, _fIVicsekf*)TO Mr<f 4-- ltlW , lSA Laplace)JEPT, A ttR Convergence Analysis of Linearized Vicsek's Model Gongguo Tang, Lei Guo Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080 E-mail: Lguo@iss.ac.cn Abstract: In this paper, the linearized Vicsek's Model will be considered. A sufficient condition will be established to guarantee the convergence of the agents' fly headings in large probability when the number of agents in the model is sufficiently large. Key Words: multi-agent system, collective behavior, linearized Vicsek's Model, convergence in large probability, graph Laplacians , normalized algebraic connectivity 1 C1 F (Introduction) 1t[1, 2, 3, 4] 5iHEtK, #ff)V Ait[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11] o j T )fS 31tY + ,4 I* SPb-fl\l l* b Pr t, T.VicsekXg f3i ,tTAfTVcsek i diM"l1J½4§}+W zh0 Ua$$;'9i4tjJATz)j jII htL-YTii1987.tf, H t5 Ci.Reyn1ds 61 o t A7I - -XThIA iTh }U{H4X:L dX Th lR4l htL f t )Y-SX rl {a)) H138+ 1TH, #*HR,*X<i o~ A-7MA,~2M Vicsekt1327WI3JTOX1EBit1t)LI7W -4 "i ET 4 *if H IL, X W &T flffi "}% Th LJAG fltUiX #X9C4$ _H_ It o t TFA tnLI A 1) AJ kln X$XpV ff A a l4R\'tUAM(spontaneous It XJ #4UV, 9 fW1 -Wi x_ g S symmetry T.Vicsekf breaking)Afg ~T~ HY1 AL198Vf, C.Reynolds,>,ttA T+tf A, 2+t%if--O ff)V A ffM 1*1@4@8T aung 8B oidrJ-flt[7] B oid8%ftP9 a ff -Lt tt #n,ffV E in A +, t~~~~t T)KT _fid SII'1A@J, ;WA$4H4tb9tAXlJA@T I't iST IEEE Catalog Number: 06EX1310 6022130 ,6034f40A 60221301,60334040. , tLilJ Wf[L tA ffAr, tIA Aff AflbFJt YIt , i l1XA 4A INXIft f tl ], I 379 >QA.Jadbabaie%2003tEf {&;. X jt t[8].0 C H' X4Vicsekt1 t WPtLh 2[ ft9a []& -t t j_4-< LM )Fl pIrqtJ*, AM k- lT < iff n XIIJv IN *Ab9S k-,M T auqs "*-, , . Xk (t) = Xk (t Yk (t) = Yk (t -1) + Vn sin Ok (t -1) Fl n b 9 f- R)Y *I fl T1WT 1[T 4EfVicsek e k fy' o-- rtl LJtfHkV T cLtsz ttt-4-,ffl Zk(t) , fl~~ I~~iN~~ ± 4~~~V L iRIY/f14 IN fi 'A' t121* Vs:4 a1q 1 X914 F.Cucker4l S.Smalet-[ 1] ' 1: H'Pfl1 k < n} "I-,-] n}2i IBflG(n, rn ,t);G(t) N12]o rX49A[J G, -L dmin Ti)LITh{H flTh[X, iL, N j-X iLtL b-LH.JF a M L1, LibN1iL b932~~A ,, AiXlAMXj # ib9tH8 itLtn tTAnx4k4I4 'fri f i, X tA sI4L8 ,A11 X14 f At I fl, 14 A , 2 dmax - s T JVk(t) ={j (Xk(t) 4Hi,tM8g,rn > i' G(n, rnt arctan diag(dk)1<k<n k2,7JRk, Rmax = maxi k Rk o tF o - jcArk (t -1) max dk 1<k<n idEZ (t) =(Zl (t), Z2 (t), Zn ()T 0 (t) = (O 1(t) 02 (t) Olnt)T yt))2 < r} { #,V/k(t)o XSo;JJzyXlk 1 X4Thfu 4g £TZk (t) = Xk(t) + iyk(t) i fl VicsektfAy', iYL-4Th+V A k -t M N A ffOj7, VllJ* k 7if[4j bflt<A JA: Ok (t) = min dk 1<k<n TiPLEb ;l 4S4SV NXn, iXtL RJi mJ o n t = 0 H49 );Xt ) k-C, XT 4 rFl 6 b9A lJt <i&§Wit* yYJt +6 oA<>13 4 ?8 JX+2(t)= nk W X k(t), yk(t)±4LX AHt.fJ1B. SC id ki-fJ\ 2tJdk,k / Ak 9a70 < rn <1, 1 Th,k, i fThWK{Thk ={z (1Tn1n)rn < |Z-Zk(0)l (%<+Tn)rn< y- t))2 + (Yk (t) = P 41hN R t#A t b r (+ maxl<k<n-1 1 ffi-bn 1MvX 2)Sflh@,it$.4tJ, 2,.. , no n-'i}UJlWHF1W A LV X4AA itL tH J,q l 4b:MieIAEltbA x - (2) j A, Laplace){F [4 ) LL, +j [V ; 'ft 2KJLaplace .f; 4L = T-112LT-112, p T-1A. Lf n-/\r44TMk 0 = Ao K A1 K AnA 1 A ; R\);ALI Za ftLfl J4 Xfft;LI yt, L #ti'H~,, l-E kwd>A tid< Lt] QiLi(Problem Formulation) Vicsek&INO.fLt 1) iA'k (t- 1) riii = 4 V _,s lA %_X@,~v A11AIE9 V9st4 fiSY H 1) JE 1 'x' tO~ (7 :7)2 ill *H -4It b9f A;iQ2J gBA:J$9(1)fH (2)x-AA, tt1 J rKjU4At, tEni Y*tKLfl n'V, At3}NAr (t) 1*SH rp] -Sf f Wp )AiH *1 LAL2 ffiiJ 1 H flXThIX l rtIX bM IN n AQt d Nn t)-23Yi, [8 d nyu V, YKYJb K fl f V I N/fl IvL T 4L AHI , (1) f , P 4L W 0, n-i J l7 f{ zk (0), 1 < KY-M *fAH n4 413SzJy4Jf bf{Ok(0),1 < k < Jr! % t H4 AJ t t 7 - : 1) + Vn cos Ok (t -1 ) Zk(t -1) + vCeiOk(t- 1) nk (t W2~~~~~~~ TAAbfWt ~~~~FPyZ,t;s1W1 b X Y i LA -ThThh, T Ifflt. tUi ni1X8ff4$N ; = AF> )J --.: 44, dtt tVic sekf--V', t n, A f. AFI )Fl 1] 0 IL"Th VTb 1 k iA 4AtVXtlQSfl fl1X&bf+Tf1; Ok( 11t" 1)4- Xk(t Vn 1) + V 0(t) P(t- 1)0(t Z(t) Z(t -1) + = ft fei.(t)(.iOl(t) eiO2(t) ftb iE -X Sin Oj (t- 1) 380 o0/142(4k2J 1) () iO,(t))T ±IER(Main Results) 3 iB(Ol(t)) = +%'~~lgn =o(rnrn), max1js,n fOj(t) -min1ijn lOj(t). Rmax ' TtMM,13JJ stL{LVicsek1%½yk ]Th#ti8 fly< Xs 1+1W fl,Wi)iX t [13]@X32 jp0LfiB;A4 Sl-X I {G(t),t to} 0 0, {O(t), t > to}442bA O(t + 1) P(t) A 6(O(t)) <22N2 d P(t)O(t) m in {XD)t-to r5n-<C log n r5 - 0(o)~ 1iSS X1fI A11l Ri 1Xl Wf I +g11*LTH$>-b9 'x'P$ 0Ffib9%2fWT f2 k )T- 1 t Ak 4± itVicsekOi lt 2 A max {1-Aj~} 1{ 1-<_j-<nmax{fl-A1, |1-An-li} = = 1-n (I + o(l)) 144 F>[]Rmax o(dmin), -YtkJRT) 4f(1ogn)1 6 o(rn)llrn = o(), logn o(fnrn) 9/ O(dmin) 13R--2 ,/IK7J9t: 3) 5(0(1)) log 22 < 1 + 1+ 0 (1)I1 log(A + £3) 1 Tin =2X 2 1328 (A + £3) Vn6(O (1)) k G(n, rn,O) I dmin dmax 1- r2 2 nrr An-, 144 (1 + o(1)) < < 2(1 = 664/in, kLnn¾KkKt, log(A + ) log( + 0()) 20(1) /( log(A + 2)) ( log(1 K log < + log 2Vn/288 w 288 (1 o(1)) = 144 log ni (I 288( + 0())) + o(1)) n 288 1 A+ £3 I + 0 (1)) 127 (I Vn x 27 X 145 Al < 2rn (1 + O(1)) 381 A+ 23m0(1 l 0(1) 2log =ogn o(rn)>Trn o(l), )JQitP fLk Fi Kk&A < = 4log + o(1)) nwr(1 nwr 4 x 2( <log 1-n tATE$ tH MsF~~~~~tflt Xft k lr]~1 l ST bfIT$ o itL , 2 r1n rn 1 9f4WQ2A88+b,Aa W~~4V i44Ah £SJ1W TI 2 41Errni rn , X 144' I 1+2)Rmax/dmin, &nt'+-k 3 <1 A+ AL= mtnn dmin < dmax K 3dmin(I + o(l)) (9 + 43/ 4, d,,i -1 A 2) Lt3( O 83 R..o EQ G(n, rn: ° ) O'§1 1+ ++ +Y = Ad (nX¾JK) A9A t, A,Kt4Vicsek4,q t] )7- 4kB jjj)j tRTM%LtW2, W bS4 min tdmax, dmin, Ai5tG Rmax V)g -I=T 3 St;A4tVicseki%!, 4Xigrn"iA( 1On)1 6 4245ih'kc, ± o(rn)Xfrn = o(l), - (A t4p HocKAlg %[14, 15], LL fifi+T Jvvrfi JX4i K ,t >to, PAiLAP(t) < P )fF4t tQ G,0(to) P(t)-- [N G(t)f4Vtfi-G, +fM Ci\AP(t) iUAt, -9-1 = 47nT/nr2 (1 + o(1)) L'F G(n, in, O){LT Ovti'4t§ I = J41 r2 log ni r2 'n < rnT/n 9JiiI0nn34%±Ct, tW1 b9ffif$3)itriiR M o[13] L. HVt}@ v5 rn I ( 1 1n < x 27 2w1tt -27 145 X 1 2 x( 145 X Guo, X 1328 44 144 of W.H.Fleming, pp. 547-566, 1998. [15] F. Xue, P. R. Kumar, "The number of neighbors needed for connectivity of wireless networks," Wirel. Netw. vol. 10, no. 2, pp. 169-181,2004. < 4 ii 2&t Vicsekf-'t. )<fk F (Conclusion Remarks) tX472[IfLt4Vicsek1%Xt X~ l4iiYKt H X1Q IFS o f1AE2 3ee Systems- nectivity in wireless networks," Stochastic Analysis, Con- 1 vn r'% cugn r logn JA8t 0t, Stochastic Press, 1993. [14Technology [14] P. Gupta, P. R. Kumar, "Critical power for asymptotic con- 1 1 1 x(x x 144 log n 1328 2 "Time-Varying Stability,Estimation and Control," Jilin Science and q VU1Ldb l'1$ E %-RHrp t [1] E. Shaw, "Fish in schools", Natural History, vol. 84, no. 8, pp. 40-46, 1975. [2] B. L. Partridge, "The structure and function of fish schools", Sci. Amer., vol. 246, no. 6, pp. 114-123, 1982. [3] A. Okubo, "Dynamical aspects of animal grouping: Swarms, schools, flocks and herds," Adv. Biophys., vol. 22, pp. 1-94, 1986. [4] J. K. Parrish, S. V. Viscido, and D. Grunbaum, "Selforganized fish schools: An examination of emergent properties," Biol. Bull., vol. 202, pp. 296-305, 2002. [5] T. Vicsek, A. Czirok, E.Jacob, I. Cohen, and 0. Shochet, "Novel type of phase transition in a system of self-deriven particles," Phys. Rev. Lett., vol. 75, no. 6, pp. 1226-1229, 1995. [6] A. Czirok, A. Barabasi, T. Vicsek, "Collective Motion of Self Propelled Particles: Kinetic Phase Transition in One Dimension", Phys. Rev. Lett., vol. 82(1), pp. 209-212, 1999. [7] C. W. Reynolds, "Flocks, herds, and schools: A distributed behavioral model," in Comput. Graph. (ACM SIGGRAPH' 87 Conf. Proc.), vol. 21, pp. 25-34, Jul. 1987. [8] A. Jadbabaie, J. Lin, and A. S. Morse, "Coordination of groups of mobile agents using nearest neighbor rules," IEEE Trans. Autom. Control, vol. 48, no. 6, pp. 988-1001, Jun. 2003. [9] W. Ren and R. W. Beard, "Consensus seeking in multiagent systems under dynamically changing interaction topologies," IEEE Trans. Autom. Control, vol. 50, no. 5, pp. 655661, May 2005. [10] A. Jadbabaie, "On distributed coordination of mobile agents with changing nearest neighbors," Technical Report, University of Pennsylvania, Philadelphia, PA, 2003. [11] F Cucker and S. Smale, "Emergent behavior in flocks", Preliminary Version, http://www.tti- c.org/smale papers/flock.pdf [12] F R. K. Chung, "Spectral Graph Theory," Providence, RI:AMS, 2000. 382