NII-Electronic Library Service
MsMo:Rs or S"AMI
tserrmr- eT TIeemvoLoGT
Vel 22,No. 1,19S8
On
Chaosand
Related
Phenomena
from
aCircuit
Containing
aHysteresis
Resistor
Family
ToshimiehiSAITO"
ABSTRACT: This article discusses chaos and relatecl phenemena from a circuit familyconsisting of
R, L, C,-R
(linear
negative resistor), and one hysteresis resistor. This circuit famity isdescribedby a canonical form of n-dimensional piecewise-linear equation containing a small parameter E. If
e issuMciently small the analysis isreturned intoa hystereticconnecting !inear systems. On this simplified system, follewingresults are shown:
(1)
For three dimensionalcase, a chaos generatingcondition {inLasota & Yorke's sense) isrigerously derived.
(2)
For a fourdimensionalexample, twodimensionalPoincar6 map isrigorously formulatedand an interestinghysteretictransitionalphenomenon
between torus and chaos isdemonstrated.
1.
Introduction
This
articlediscusses
chaos and relatedphenomena
frorn
a circuitfamily
consisting ofR,L,C,-R
(linear
negative resistor), and onehysteresis
resistor.We
propose ann-dimen-sional canonical
form
equation for the circuitfamily.
It
is
piecewise-linear and contains asmall
parameter
e.In
the case whereeissufficiently small the mathematical treatment
is
simplified andfollowing
results are shown:
For
a threedimensionai
case,Poincar6
re-turn map
is
defined
as an one dimensionalmapping,
hence
a chaos generating conditienis
rigorouslyderived.
The
rneaning of chaosis
that the mappinghas
an absolutelyconti-nuous
invariant
measure[1].
For
afour
dlmensional
example, a rigorousformulation
of a twodimensional
Poincar6
map
is
given and some numerical results areshown.
Especially,
aninteresting
hysteretic
transitional phenomenon
between
torus andchaos is
demonstrated.
In
addition, someIaboratory
experimental results are shown."Chaos in electric circuit"
have
been
stu-died
withgreat
interests.There
are someexcellent analytic works such as "Double
Scroll
Farnily
[2]"
and "ForcedJosephson
Junction
circuit[3]".
However,
variouspro-blems
shouldbe
considered toclevelop
thestudy.
For
example,1)
Construct
sorne general theories.Pre-sent works mainly
depend
on some exampleclrcults.
2)
Consider
higher
order systems.We
can certainly
discover
newinteresting
phe-nomena even
for
four
dimensional
auto-nomous circuits.
This
article gives some impact for theseproblems:
Then-dimenslonalcanonical
form
seems to
be
a starting stepfor
theconstruc-tion of a general theory.
The
"hysteretictransitional phenomena"
in
thefour
dimen-sional example suggests the great
interests
of
higher
order systems.And
rigorous prooffor
the threedimensional
case seems tobe
developed
to more generalized one.* ptx=#a man
vafn62 rp 11 A 8 HMN
2.
Canonical
Form
Fig.
1(a)shows the circuitfamily
defined
as below.
A)
NR
is
a current-controlled nonlinearresistor which
is
characterized byFig.
1(c):
.,..f<,,,=l";(,S-2Efr)・(i.E./r,.
,,,
k
r(i,+2E!r),i,f{-E/r
B) Lo isa small inductor and itis
assum--,13
re
ecrees
\re
et
Loi ilNR>v,5v Alinearnetwork iconsis.tingef -R,R,LC e HN,-(a) N rlrl . + (b) -']1Vl r= Vl2E''tr N r N ']]-'''-2E ±2E (c) (d)Fig. 1. (a)The circuit family,
(b)
A realizationof IVR,
(c)
Characteristicof NR,(d)
acteristic of the hysteresis resistor as Lois
shorted.
ed that
NR
operates as ahysteresis
resistorof
Fig.
1(d)if
L,
is
shorted.
C>
N
is
alinear
network consisting ofR,
L,
C,
and -R.
D)
In
thegraph
of the circuit family,there are no
C-only
cutset and noL-only
tleset.
Applying the
general
theory of stateequa-tions
[4],
the
state equation of the circuitfarnily
is
givenby
theform:
,d,
(?i)-B
(i)-J'ti
(,)
d
it=V-f<ii)
,Lo
dt
where v,=(v,i,・・.,v,.)T
is
abranch
voltagevector of capacitor
branches
in
N,
iL=:(i",...,
iL.)
is
abranch
current vector ofinductor
branches
in
JIV;B
is
a coeMcient matrixde・
termined
by
the structure ofN,
and J=(1,O,
・-・,o)r.
ca
22 ig M1e
Next,
via the rescalings:xiis v/E , xi+i =- v,t/E , xj+.+i =-riJfE ,
z=ri,!E,
<x=(xi,・・・,xpt)',
IV'==1+n+m,
i--1,・
1=1,.・・,m),
r=-tl(rC), e=-L,1(r2C)the equation
(2)
is
transformedinto
(e2==xi-h(z)
be=Ax-J(z-x,)
,
where
.d
X-d,X, h(2)=2+lz-11-lz+1].
Moreover,
we try to transform thetion
(4)
into
a cannonicalferm.
Define
notations:
t,:'E".;fti'.';
£
,xi'f'l
1sl-Al==sN+aN-isN"i+・・.+cris+aoJ
and define the transforrnation:
M.8L&i&
1,
O, ・-・O al atA : . a,AN-t X=(Xl, xiX2X3: .X4(X=
T・x, ・・・,XN)T)
By
using this transformation withHamilton's
theorem, the equation(4)
formed
into
theform:
I/:i2
'-Xh-(.);
e(z-J<),
whereHere,
it
tions
of all simplifiedif
T
is
notO
1
O----O
10 'o
'・ 1 -cro,-al, ''''',-crN-1 e=(2, e,,・・・,e.) =2・V
is
remarkable that allelements
in
the
into
theform
of thesingular.
Namely,
. ..,nt(3)(4)
equa-some(5)
(6)
Cayley-.Istrans-(7)
state equa-circuitfamily
is
equation(7),
solving(7)
is
.-NII-Electronic Library Service
On enaos and Relatedllhenomena
from
a arcuit fumilyXi X,=h(Z) b1 . N s. J ss-e oNs 2Z N -t s. -1a
Fig. 2. Vectorfieldfors-O.
suMcient to clarify the complete
dynamics
of the circuit
family.
The
equation(7)
is
the
N+1
dimensional
piecewise-linearequa-tion containing a small parameter E,
i.e.
apiecewise-linear version of so-called
"Con-strained equation"
[5].
For
the case whereNR
operatesasahy-steresis resistor, the mathernatical treatment
issimplified
dramatically.
Namely,
this caseis
equivalent to thefollowing:
In
the case of where s issmall enough, zrnoves
far
faster
thanX
and alrnost allsolu-tions are constrained on stable
parts
of themanifold given
by
Xl==h(z):
(see
Fig. 2)
S.={X]
a1Xl!)-1,
Xl=z-2}
,or
Srv={Xz1
Xlsg1,Xl==z+2}
The
dynamics
onS.
orS-
aredescribed
by
X=A(X-P), for XES.
(8-a)
X=A(X+P),
for
l!CES-
(8-b)
wherer
P=
(P,,
2,e,,・・・,e...,),
1
Pi=-
(eN+crN-LeN-i+・・・+a2e2+2ai)
ao
In
addition,if
a solution onS.
exceeds thethreshold
Xl=-1,
then itjumps
ontoS-,
holding
X==const.
andif
a solution onS-exceeds the threshold
X=1,
thenit
jumps
onto
S.,
holding
X=const.
(In
following
parts, we ornit z).
That
is,transitionsbe-tween
S+
andS-
is
asfollows:
g::gl
[Ig
gl-N,[gib.li
ll
i
il
g::ggg:
ri}
(9)
Thus,
the equation(7)
is
simplifiedinto
thetwo syrnmetric linear equations
(8-a)
and(8-b)
withthe
hysteretic
transition(9).
Wecall
thissimplifiedsystemas"Idealsystem". This
system
is
not correctin
the rigorousmathe-rnatical sence but well explains the actual
dynamics
of the circuit.In
addition, thejustifiability
of "Ideal system"is
analyticallyexplained in an engineering sense for N=2
[6],
Next,
we show some resultsfor
thissystem.
3. The Three Dimensional Case
F.or
N=2,
"IdealSystem"
is
(ilf')=(-e
21)(XiLPi), for(x;y)es.
.(i')==(-9
2:)(Xy++P2i),for
(10)
with the transitional condition
(9),
where
1
v==cro, -2a=-ai,
Pi-
(4a-02).
v
For
a simplicity, pararneters are assumed tobe
Pi=1,
a>O, v>a2(di=-Vv-o2).
(11)
In
this case, eigenvalues are a±j'toNandPi=1
implies
that equilibrium points are on linesX==-1 or X=1.
Next,
define
some objectson
S,,
for
the definition of the Poincar6re-turn map
(see
Fig.
3).
Li{X
Y[X=1,
Y}l-2}
,-1Y, lr.s.s. Y MsN 21!r1xL,X 2 --x}o-1N!1-/-xLl[L72----DO-p1 s'-DL!1.-X
/Y,
-r2--1'o Lt-)rJ2-ie -MFig. 3. Trajectories on S+ and S-.
-reecr* Jk\re pt
za
22 if M 1 e LF (Yo)MT(D)L--r i l-T--'-: 1 -LD-2 L, Lz:
---e-.V-: 1. .,.;i..4 -11 1 , 2-D lx LLiI/- -1---LZ--d x F--;----, (-2) xe,- 1' ,l Lt11t 1 v-- 1-d -M.' --1 dL;L' ,L,L, -M -D2-2D rvI
Fig. 4. An outline of Poincar6
Yomap.
M:
The
point
onL
such that thetory started
frorn
it
passes(1,
-2).
D:
The
point
onL
such that thetory started from ithits
(-1,
2),where
D>-2
is
assumed.
L,i{X
YIX=1,
DE{
Y<M}
,
L,!{X;
Y'[X=1,
-2"<Y<D}
.And
define
syrnmetric objects onS-.
L,={X,
YIX=-1,
Y:f{l2}
,L,,={X; YIX=-1, -M<
Ys-D}
,
L,,={X]
YlX=-1, -D<Yf{2}
.Consider
trajectories startedtrom
L,ULt
atr=O. A trajectory started
from
a pointYh
on
Li
intersects
L
at r:=n/w(Let
Yl
be
thisintersected point).
Also,
a trajectory startedfrom
a pointYh
onL2
hits
the thresholdX=-1
(Let
}1 be thishit
point),and at thismornent,
it
jumps
onto a pointYl
onL.
Hence
it
follows
that we candefine
the nextone
dimensional
mapping:
T:
(L,UL,)-(LUL,),
YhHY,.
(12)
Since
the vector fieldonS-
is
symmetric tothat on
S.,
we can alsodefine
the mapping:T:
(L!uL,,)
-(LuL,)
, Y6b Yl .
(13)
Hereby
behaviors
of trajectories aresimpli-fied
into
thefollowing
onedimensienal
Poincar6
map whose outlineis
shownin
Fig.
4:
IZ
q
z
8
ii
Uilii
11
1liiiii
'tli・t
l
' 'I'
6 .es.1.15.2Fig. 5. Chaos generating region.
T:
(L,uL,uLIuL,r)->(LuLt),
YheM.
(14)
This
rnapping can be formulated rigorouslyhence
thefellewing
resultis
obtained.
[THEOREM]
Let
2 aq='
v-iJ-
, 6=v-iJ'
,(g*Etan-i-2-
, to=tw)
.4
e:(g--PD<q< 21a ,-Zcot-(ii,2.e2)
(15)
e2-.Vg'He-:=
<1
is
satisfied,then
there
exists a setJ
andits
subset
i
(lcJ)
in
thedomain
of
T such -thatT(I)cL
Tes(Yh)e4for
allYh
in
L
fbr
aayinteger
n, and thenIDT(Yb)[>1
for
almostall
Y6
in
L
whereDT
is
thedt:ffbrential
coelf-ficient
of
T,
This
theorem meansthat
T:
IL>l
is
stable,is
expanding(DTI(Yb)1>1),
andhas
anab-solutely continuous
invariant
measure[1].
Hence
almost all orbits of T are chaotic.Proof
ofthis
theoremis
shownin
[6].
The
condltion
(15)
is
satisfiedin
the shadedre-gion
in
Fig.
5.
We
have
actually observed-16-NII-Electronic Library Service
this
Le-OiL
On Chaos and Related Rhenomena
from
aNclv,v,rcx
Fig. 6. An
chaotic
-g
example circuit forIV=3.
attractor
from
somecircuit
[6].
4. A Four
In
this section,four
dimensiona1
circuitdynamics
(i):-C
i・ eth=x-h(w) whereh(w)==w+lw-11-1w+11.
Moreover,
by using the transformation:
(ilil)=-(,,),l
0
21
-iXi),the equation
(17)
is
transformed
into
thecanonical
form:
(
X
9=(,[2agi),
-2(2'
-6), 2s2i)(ll)L
where .f<・)describes
andis
given x-v,IE, y=v,IE r!t/(rC) ,The
equation DimensionalExample
we consider an example ofcircuit
(see
Fig. 6).The
is
described
by
dv,
・・c
=-t-11dt
dv!
. C ==gv2+1dt
(16)
diL
=Vt-V2dt
di,
=Vi-jC<ii) ,Lo
dt
the characteristic ofNR
by
(1).
Next,
via a rescalings:, z=ri/E, w!riilE, 26=- rg , pii!r2c!L , E=-
L,f(r2C)
,(16)
is
transformedinto
2i
ij,
-g・xi)-(g)(w-.,
Circuitthmily-( ITL I
Ip
)
(w-x)
eto==X-h(w)(18)
Ifsis
small enough, "Idealsystem" of this
equation
is
glven
by
X=A(X-P),
for
XES.
(19-a)
X=A(X+P),
for
XeS-
(19-b>
where
Ar=(X,
Y;Z)', and.--..(g
,i
?)
Np(2E-1),
-2(p-6),26-11,
2
P=-ip,,
2, -2),Pi=26-1
and the transitionalcondition
is
(9).
For
a simplicity, eigenvalues ofA
is
as-sumed to
be
s=2,a ±]'w
(ca=
Vp-ff2),
wherea>O, v>o2, 2>2a.
In
this case, a, p, and v are given explicitlyby
2
and a:26==A+2a+1, p=(262+-22a.)A , ,=2+22ap
Fig. 7.
-z
Vector fieldson S+ with some objects.
-17-相模工業 大 学 紀 要 第 22 巻 第 1 号 コ 」 r 、 「 こ (a ) ユ 臼一 1 ● ワ 」 5 z 日
2v
ロ エ2v
つ 」 ! 尸 二 (b
) 1 ド−・ !「 丶 { ’・t \ s. \ 」 図L
−_ −1 記 5 z 日 3Y2 (c )1
払 − 臼 一 , , 辱 曾 ・ ● , 「 孕 1 2 5 Z 8 ヨ Y2(
d
) ユ 2 −1
2 5 Z 8Fig .8. Some attractors by numerical and laboratery experiment for p=12.(a): Periodic attractor
forδ= .7
, (b):Torus attractor for δ
= .8,(c):Periodic attractor forδ=.905, and (d): Chaotic
attractor for δ= .92.
Consider
the vectorfield
in
S
+.Let
E γ bethe eigenspace corresponding to the real eigen
value and
let
Ee
be
the eigenspace correspond −ing
to the cQmplex eigenvalues .They
aregiven
by
E
『 ≡ {X
,】r
,Zl
(Z
十2) = 1(y
−2
):R2
(X
−P1
)}Er
≡ {X
,Y
,Zl
(Z
+2
)− 2σ(Y
− 2)+レ(X
−A
)=0
} (20
).NII-Electronic Library Service
On Chaos and RelatedPilenomena
from
a crrcuitFlamilyhl" L! tL・/.g :-/.ti.. 1 ; ]) 2 e .99 .9
Fig. 9.
(a):
Bifurcqtion.'diagram for increasing6
(p=12).
In
addition,define
some objectsin
S.
(see
Fig.
7):B+={X,
Y;
ZIX=
1},B-={X;
Y,
ZIX=-1},
B.i{X,
Y
ZIX=1,
(Z+
2)
-2a(Y- 2)+vT(1 -Pi) <O} ,B.i{X
Y,
Z
1X=1Y>
-2},
B'n={X;
Y;Z
[X=ml,
Y<2}.
(21).
Consider
a trajectory startedfrom
a point(1,
Yli,Zli)eB'.
Such
a trajectory musthits
Bk
at sometpositive
time T,, since theex-ponential component of
X
is
negative andsince
X<O
onBS.
Let
(-1,
Yl,Z,)GBS
bethis
hit
point.At
this moment, itjumps
onto the
point
(-1,
Yl,Z,)
in
S-.
Here
itisremarkable that the trajectory started
from
(-1,
Yl,
Zi)
in
S-
is
symmetric to thetrajec-tory started from
(1,-Y,,-Zi)
in
S..
Hence
.9t fi
(p==12),
{b):
I l/ .".(a) (b) D e 'S2Bifurcationdiagram fer decreasing
it
follows
thatbehaviors
of trajectories aresimplified into orbits of two dimensional
Poincar6
map:T:
B.-B.,
(Yh,ZD)->(-Yl,-Zl)
via(Z,Z,)
(22).
Since
the equation(19-a)
is
linear,
an implicitforrnulation
of this rnappingis
easilyobtain-ed as
below:
Yl=
oa.
F(T,
Y6,
Zo)ir-tt+2
,
(23)
02
Zi=
e.2
F(T,Yli,
Zh)rt-ri-2
,whereF(rY6,
Z6)=exp(oT)(A
cos toT+B sin tor)
+Cexp(aT)
c=(Zh+2)-2a(Yh-2)+v(1-P,)
22-2o2+v '
-19-Npt=*
lt\resiva 228
ca
1e 3Y2Ol(
"-L
s9Y2
2T5
ze@i
a.-tAJ
s
zT
x・
:sp.
Y:2?sa 1 ":tt
.--.fig・
T
, , 'Observable phenomena are O-@-@-@-O, for inereasingoj
and @-,@.(Fig.8,{c))--@-@.O, fordecreasinge. 5Z8@
s
-,se2
2Ts
zs -t 3Yz 1B-tz
i . . . .T5
z8l
2T
s2,
::t
E・@
Y2 "x8 zso
: fi==.895,@
&@:
sx,i
sg・
T
Fig.IQ. Hysteretictransitional phenomena,
(!)
ti=.913,
@:
6=.915, and p= 12.A=1-P,-C
and 1 ,B=
to(Y6-2-aA-2C) ,(24)
T,
is
the solution of the equation:
F(T,,
Yb,
4)+P,+1=O
(2s)
. -1S
Z Y2 SZ8T
-t Z 5 6=,8975, (D: Z8 fi=.899,@
&@:
In
actual calculations, we solve thisequationby
usingNewton-Raphson
method.Fig.
8
shows some example attractors of
T
withcorresponding
laboratory
experimental results.In
thisexperiment, wehave
verified thatNR
NII-Electronic Library Service
On Chaes and RelatedPhenemena
Here
we would liketo
demonstrate
aninteresting
hysteretic
transitionbetween
torusand chaos.
Fig.
9
(a)
shows abifurcation
diagram
whichis
obtained by plottingY
co-ordinates of attractors
for
increasing
6
andfor
p=12. At each step of a,thelast
pointof the old step
is
used as theinitial
point ofthe new step and transient states are omitted.
On
the otherhand,
Fig. 9(b)
shows thedia-gram
for
decreasing
6
whichis
obtainedby
contrary rnanner.
As
showninthese
figures,different
attractors are observedin
intervels
A
andB.
It
irnplies
that at least twoat-tractors exist
in
A andB,
and that ahy-steretic transitionoccur.
Fig.
10shows sometypical attractors observed at points
O
to@
in
Fig.
9.
Consider
the case of increasing a(Fig.
9(a)).From
6:=.89 to fi=:a,there exists one torusattractor as
Fig.
10
(iD.
At
j=a,
the newperiodic attractor as
Fig.
10@
is
born,
but
observable attractor
is
Torus
of@
in
inter-val
A.
In
thisinterval,
thishidden
newat-tractor grows to "Periodic
Torus
likeat-tractor" as
Fig.
10
@.
At6=:b,
the old torusattractor
dies,
thus "PeriodicTorus
likeat-tractor"
is
observed.After
it,
this attractorfades
to 11-periodicattractor asFig.
8
(c)
orFig.
10
@.
These
trans'i`tionsnearA
areschematically indicated
by
down-ward
arrowin
Fig.
10.
The
transitions nearinterval
B
aresome-what similar to
it.
Namely,
at O=c, thenew
8-periodic
attractor asFig.
10@
is
born,
but
observable attractoris
the old 11-periodicattractor as
Fig.
10
@.
And
at 6=d, the oldattractor
dies
thus the 8-periodicattractor isobservecl.
Finally,
this periodic attractorgrows to chaotic attractor
(Fig.
10@->Fig.8
(d)).
On
the otherhand,
the case of decreasing6
canbe
explainedby
contrary manner.It
is
indicated by up-ward arrow in Fig. 10,frem
a CVrcuit Fizmdywhere "birth and "growth" of up-ward arrow
correspond to "death" and "fading" of
down-ward arrow, and so on.
These
explanationis
a conjecture.Now
we are trying to give some theoretical
con-firmation
for
it.
However,
these resultssug-gest the great interests
in
higher
ordersystems.
5.
Conclusion
We
have defined a circuitfamily
contain-ing one
hysteresis
resistor andhave
proposeda canonical
form
equation whichdscribes
it.
The
equationis
simplifiedinto
"Idea1System",
a chaos
generating
conditionis
rigorouslyderived
for
threedimensional
case, and aninterestinghysteretic transitional phenomena
is
demonstrated
for
a fourdimensional
ex-ample.
The
major present problemis
togivesome theoretical confirmation
for
the fourdimensional
exarnple.Acknowledgement
The author deeply appreciates the
sugges-tions frorn
Prof.
S.
Mori
ofKeio
universityand
Prof.
M.
Hasler ofSwiss
Federal
Insti-tute of
Technology.
References
[1]
A. Lasota andJ.A.
Yorke, Trans. Amer.Math. Soc,, 186 (1973),481.
[2]
L.O. Chua, M. Komuro and T. Matsumoto,IEEE Trans. Circuits Systs.,CAS-33, 11
(1986),
1073.[3]
F.M.A. Salam and S.S. Sastry, IEEE Trans.CircuitsSysts.,CAS-32, 8
(1985),
784.[4]
Y. Kajitaniand S.Shinoda, "Networklysis",
Japan
Science& Tech. Press, 1979.[5]
H. Oka and H. Kokubu, Tech. Rep. IECE