American Journal of Computational Mathematics, 2013, 3, 56-61
doi:10.4236/ajcm.2013.33B010 Published Online September 2013 (http://www.scirp.org/journal/ajcm)
Differential Games of Pursung in the Systems with
Distributed Parameters and Geometrical Restrictions
M. Sh. Mamatov, E. B. Tashmanov, H. N. Alimov
Department “Geometry”, National University of Uzbekistan Named After M. Ulugbek, Tashkent, Uzbekistan
Email: mamatovmsh @ mail.ru
Received 2013
ABSTRACT
A problem of pursuit in the controlled systems of elliptic type without mixed derivativ es with variable coefficients was
considered. The model of the considered system is described by partial differential equations. The players (opponents)
control parameters occur on the right-hand side of the equation and are subjected to various constraints. The first
player’s goal is to bring the system from one state into another desired state; the second player’s goal is to prevent this
from happening. We represent new sufficient conditions for bringing the system from one state into another. The fi-
nite-difference method is used to solve this problem.
Keywords: Pursuit; Pursuer; Evader; Terminal Set; Pursuit Con trol; Evasion control
1. Introduction
Some problem formulations in the theory of differential
games may be illustrated by motion of two controlled
objects, pursuer and evader. Let in the course of motion
the objects continuously observe each other and at each
time instant correct their motions depending on the in-
formation about the adversary. Depending on the pur-
suer’s aim, the problem of pursuit is then formulated as
follows: using the information about the evader, at each
time instant t select a cont rol such that coincid enc e of the
objects’ spatial coordinates is reached as soon as possi-
ble.
The majority of studies consider the case where be-
havior of the lumped-parameter model described by a
system of ordinary differential equations. This scheme
encompasses many problems of differential games aris-
ing in diverse filed of the natural sciences. The mathe-
matical issues of the differential games describing the
lumped-parameter systems were developed in detail.
In many applications, however, the lumped-parameter
models describe phenomena inadequately. It often turns
out that a system which is optimal in the sense of a sim-
plified model does not use the additional designed-in
potentialities of control. The distributed-parameter mod-
els obeying the differential equ ations with partial deriva-
tives offer a better, more adequate description. Use of
these equations also gives rise to various game problems
of which one is the subject matter of the present paper. It
focuses only on the problem of pursuit. Therefore, we
make an assumption about the nature of information for
this problem.
2. Formulation of the Problem
The operated distributed system described by the elliptic
equations (see, for example, [1,2]) is considered
22 22
(,) /(,) /((,),(,))axy zxbxy zy fuxyxy
 , (1)
/(,)(,zxyzx)y

 , (,)xy
where (,)zzxy
– unknown function, ,
– continuous functions in
with border
(,)axy
):0 1,
x(,)bxy
0 1}
y {( ,xy
, (,)
x
y
– smooth function on
,
– external normal. It is supposed that there is a positive
constant
such that for any the inequal-
ity, (, )xy
(, )ybx
,(, )uuxy
, (,)
x
y
2()L
– operating func-
tions is executed from a class . The first (pursuing)
player, (pursued or escaping) the player, uP, Q
,
P and Q – nonempty compacts in disposes of
function
1
R
(, )
x
y
second of function . The ter-
minal set (, )uxy
1
1
M
R s allocated.
Definition 1. In a task (1) it is possible
– comple-
tion of (0)
prosecutions from “boundary” situation
(,)
, if exist function (,,)uxyP
, Q
,
(, )xy
, such that for any function 0(,)
x
yQ
,
(, )xy
0
((,),xy
the solution of a task (1) where
0
zx(,)t
,)xyu u
, 0(,)
x
y
, gets on a set 1
I
M
,
at some (, )
x
y
 , 01
(, ):(, )
x
yzxy
 
 IM
 where
(1I,1)
.
Decompose the Euclidean space of variables
2
R
(, )
x
y by the planes i
x
ih
, , and 1/hr0,1, ,i
j
yjl
, 1/l
, 0,1, 2,,j
into parallelepipeds
Copyright © 2013 SciRes. AJCM
M. Sh. MAMATOV ET AL. 57
(, ){(,) :(1),(1) }
ij i
x
yih xihjlyjl , and r
being some natural numbers. The points (, )
ij
x
y
hl
belonging to a set are the nodes of the grid
.
Each node has its neighbors. If all these neighbor nodes
also belong to the grid, then the node
hl
(, )
ij
x
y
is referred to as “internal”, otherwise,
(, )ihjl(, )
ij
x
y
2
1
(),h
22
(),
/,
,,, ,
, ,
ij
is called the “boundary” node. The set of all boundary
nodes is called as border of net area and is designated
through .
h
2
11
2
11
22 11
22 1
/(,)((,)(,))/2 (),
/(,)((, )(, ))/2(),
/ (,)((,)2(,)(,))/
/ (,)((,)2(,)(,))/
iji ji j
ij ijij
iji jijij
ijijij ij
zxxyzx yzx yhOh
z yxyzxyzxylOl
z xxyzxyzxyzxy
zyx yzx yzx yzx yl




 
 
 
 
,ij
z
,1
,,1,,,1 ,,1
(2)/ (2
0,1,,1; 0,1,,1.
ijijij ijijijijij
azz zhbzz z
irj
 


(, ):
i jij
Replace the internal nodes of the derivatives (1) dif-
ferential second-order accuracy of approximation ratios
with formulas
2
O
Ol
ij
f
,
ij ij
h
22
)l
,
Substituting these ratios in (1), having rejected an error
of approximation of derivatives, we will receive the dif-
ferential equations for unknown
(2)
where the following designations of values of coeffi-
cients and the right part in a hub
x
ya
,,
,
ij ij
b dc
g
f
,((,),(,)), (,)
ijijijijh
ffuxy xyxy
, for example are entered
l
,ij
z
,ij
z
1,0,0, 0,1,0,
,1,,1,, ,
,1,0,0 ,1,0,0
,,1 ,,,1,
()/()/2, (0,1,
()/()/2,
()/()/2, (0,1,2,
()/()/2
jj jjjj
rjr jrjrjrjrj
ii iiii
ii iiii
zz hzzj
zz hz z
zzl zzi
zz lzz
 






 
 
 
 
2(r

21)
1)r
Ratios (2) contains except unknown in internal
nodes also unknown on border of net area. For
boundary nodes we will write down a ratio
,,
,
)
(3)
Thus, we will receive system of r
,1i
z

,ij
z
,i
z
equa-
tions with the same number of unknown .
Using boundary conditions (3), we will express ,
through ,
,0i
z,1i
z
,1,0,0 ,0,0,0
,,,,1,
(2)/(2)2 (2
(2)/(2)2 (2
ii iii
iiiii
zl lzll
zl lzl

. Let's have
,
).
i
i
)
l


 

z z
(4)
Using these ratios, we will exclude in system (3) un-
known ,1i, ,i
. If to enter designation 2
/hl
2
1,00 ,0,11,0,0
1, ,1, ,11,,
1, 1,2,, 11, 1,
(2 2),
2(1)(1,2,, 2),
(2 2)
(0,1,2,,1),
iiiii
ij ijij ijijij
ii iii
zkzzz
zz zzzF
j
zz kzz
ir
 
 


 
 
 
, we will
receive system
1
i
i
F
F


 

(5)
where
22
,0 0,0,0,
2
,1 ,1,,
2/(2);
(1,2,, 2);
2(2).
ii iiiji
ii ii
,
j
F
hfllF hf
j
Fhf l l
 





 
(6)
This system can shortly be written down in a look
11
, (0,1,2,,1).
iiii i
zAzzFi r

  (7)
where
,0,1, 1,0,1, 1
(,,,); (,,,)
iiiii iii
zzzzFFF F



,0
,
2(1 )000
2(1 )00
02(1)00
000 2(1)
i
i
i
k
A
k
















(8)
Boundary conditions (3) and (5) can be copied in a
look
1,0,0,0,0,0,
0, 0,0,
1, , ,,, ,
,, ,
(2)/2(2 )/(2)
(0,1,2,,1)
(2 )/(2 )(2)/(2 )
(0,1,2,,1)
jjjjjj
jj j
r jrjrjrjrjrj
rjrjrj
zh hzhh
kz yj
zh hzhh
kz yj


 
 
 
 
(9)
where
0, 0, 0,0,0, 0,
,,,,,
(2)/(2) (2)/(2)
(2)/(2) (2)/(2).
jjjjjj
rjrjrj rjrjrj
khhyh h
khhyh h
,

 
 
 
;;
(10)
Having put
00,00,1 0,1,0,1,1
0,0
0,1
0
0, 1
,0
,1
1
,1
(,,,); (,,,).
000 0
0000
;
000 0
000 0
0000
,
000 0
rrr r
r
r
r
yyyyyyy y
k
k
X
k
k
k
X
k













 
 
(11)
it is possible to write down systems (9) in such look:
1000
11
,.
rr
zXzy
zXzy


r
(12)
Finally we have the following system of the equations:
1000
11
11
(1,2,,1)
iiiii
rrr
zXzy
zAzzF ir
zXzy

 

(13)
Instead of game (13) we will consider more the gen-
eral game described by system of the equations
0001 0
11
1
(,) 11
nnnnnnn nn
NNNN N
Cz Bzf
AzCzBzfunN
AzCz f


 

,,
(14)
where m
n
zR
, 0,nN, ,,
nnn
A
CB constant
square matrixes, mm
,
nn
u
– operating parameters,
n
u
Copyright © 2013 SciRes. AJCM
M. Sh. MAMATOV ET AL.
58
prosecution parameter, n
– beanie parameter, nn
uP
p
R, q
nn
QR
 , n and – nonempty sets; n
Pn
Q
f
– the set function displaying
p
q
RR in . Besides, in
the terminal set is
m
R
m
R
M
allocated.
Definition 2. We shall say that from “boundary” situa-
tion 0
(, )
N
f
f it is possible to complete pursuit for
steps if from any sequence N
12 1N
,,,

of the values of
evasion controls it is possible to construct a sequence
121
of values of the pursuit control values such
that the solution
,, ,
N
u
uu
012
,z1
{,,,, }
NN
zzz z
of the equation
00
11
1
nn
NN
B
z


010
(,) 11
nnnnn nn
NN N
Czzf
AzCzBf u
AzCz f

 
,,
.
n N (15)
Gets on :i
M
zM for some . Thus for finding of
value i
n
u it is allowed to use values n
and n
z.
Note that the type of systems (14) is difference schemes
for elliptic equations of second order with variable coef-
ficients in any field of any number of dim ensions [3-14].
Solution of problem (14) will be sought in the form
11 , 1, 0,
nnn
zz nN
1n2, ,N



(16)
where 1n
mm
– uncertain while a square matrix of the
sizes , and 1n
– a vector of dimension m.
From a formula (16) and the equations of system (14) for
there are recurrent ratios for calculation of
matrixes
11nN 
n
and vectors n
. Really from a formula
nn
z
(16) 1n
z
n

 substituting it in (14) we will receive
].
nn
1
1
11
() ,),
11;
()(, ;
()(),)
nnn nn nnnn
nnnn nnnn
nnnnn nnnn
AzzBz f
nN
CA zzfu
zCABz CAfA
 

1
n
n n
n
C
B
(
)
[(
n
n
nn
u
A
u


 

 

1
()
()
1, 2,
nn
n
2,,
)
nn
N
A
Equating now the right parts of the last and (16) equali-
ties we will receive
1
1
1
, 1,
[(,
, .
nn n
nnnnnn
CAB n
CA fu
nN
1;
],


 
 
Further from (16) and the equations (14) for 0,nN
,
there are the initial values 1
, 1
and , allowing
beginning the account on recurrent ratios. From (14) and
(16) for we will have
N
z
11
,
0n
11
1
00
zC
00 00
, zCBfzz1



10
CB

0
And, therefore
11
1
00
, .Cf



In the same way for we have
n
N
N
()
NNNNN N
A
zCzf


N
A

N
or
1
()(
NN NNN
zC fA).


Uniting, we will write out final formulas
1
1
11
0
(), 1,2,,,
nnnnn
CAB nNCB
0

  (17)
1
1
1
10
0
()((,)
1,2,,1. ,
nnnnnnnnn
CA fuA
nNCf
),

 
 (18)
11 1
1
(, ),
1,2,,0,
nnn nnn
NN
zzu
nN Nz



  (19)
It is clear, that if in game (17), (18), (19) n
zM
that
in game (14) too game comes to the end. Therefore fur-
ther instead of game (14) we will consider discrete game
described by system of th e equations (17), (18), (19).
Before giving determination of stability of algorithm
(17), (18), (19), we will provide some data from linear
algebra.
Let A – any square matrix and ||
mm||m
x
be norm
of a vector in , then the norm A is defined by equal-
ity
m
R
0
||||sup||||/|||| .
mm
x
A
Ax x
For a case of Euclidean norms in we have
m
R
|| ||A
, where
– maximum on the module own
value of a matrix
A
A
.
Without the proof we will give the following known
lemma (see [15]).
Lemma 1. Let for some matrix norm the square matrix
meet a condition || ||1
A
q
. Then there is a matrix
1
()EA
and || 1
)|| 1/(1EA
( )q
.
Let's say that the algorithm is steady if the assessment
|||| 1
j
for 1jN
is carried out.
Lemma 2. If
j
C for 0jN
– no degenerate ma-
trixes and
j
A
and
j
B – nonzero matrixes for 1j
1N
also are satisfied conditions
11
0
0
11
||||1, ||||1,
||||||||1, 11.
NN
jj jj
CB CA
CA CBjN



And at least in one of inequalities the strict inequality
takes place, there are return to the .
j
jj
CA
matrix and
|||| 1
j
, here 1
10
0
СB
,
1
1(), 1
jjjjj
CA BjN1.

Proof. 1
10
0
|||| |||| 1CB
, suppose, that |||| 1
j
also
we will show 1
|||| 1
j
. After a course the proof of this
fact we will receive existence of a matrix 1
()
jjj
CA
.
Really from conditions of a lemma we will have
11 11
||||||||||||||||1 ||||1.
jjj jjj jjjj
CACACA CB
 
 
As 1
j
jj
CA
square matrix that owing to a lemma 1
there are return to 1
j
jj
ECA
and
j
jj
CA
matrixes
and 1
||)|| 1
1/|| ||(
j
jjj j
CBECA

. From here and from (17)
we will receive
111
1
111
|||| ||()||
||()|| ||||1.
jjjjj
jjjjj
ECA CB
ECA CB
j



The proof of the lemma is complete.
Copyright © 2013 SciRes. AJCM
M. Sh. MAMATOV ET AL. 59
3. Main Results
Everywhere further it is supposed that 01
M
MM ,
where 0
M
– linear subspace , 1
m
R
M
– a subset a
subspace, – orthogonal complement of 0
L
M
in .
Denote we will designate a matrix of orthogonal
design from on .
n
R
m
RL
Let ,
(0){0}W
1
1
0
11
()( ,)
()(), 1.
NkiNki
k
N
kNki NkiNkiNki
iQ
Wk P
WkWkkN
 
 
 
 
(20)
Theorem 1. Let N be the smallest of the numbers k,
such that
1().
NkNkN N
zWk
1



(21)
Then from “boundar y” situation 0
(, )
N
f
f it is possible
to complete pursuit for N steps.
Let now ,
21
(0)WM
11
11
22 11
22 111
(1)[(0)(,)],
()[ (1)(,)]
Nk Nk
NN
Nk NkNk
Q
Nk NkNNNN
Q
WWP
Wk WkP

 
 


 


1
(22)
Theorem 2. If N be smallest of those numbers,
for each of which takes place inclusion
k
()
1
zW
k
NkNkNN 2


 (23)
that of “boundary” situation 0
(, )
N
f
f it is possible to
complete pursuit for N steps.
Let

1
01 10
(),,,:0,1
k
kki
i

 
i
],
and
1
11
0
313
()
(())
(,)
0,
(0), ()(()), 0.
Nki Mki
k
k
k
iNkNki NkiNkiNki
iQ
k
W
MP
kN
WMWkW kN
 





(24)
Theorem 3. If 1
M
– a convex set and N be small-
est of those numbers . For each of which inclusion
takes place k
1().
NkNkN N
zWk
3


(25)
That of “boundary” situation 0
(, )
N
f
f it is possible to
complete pursuit for N steps.
It is easy to be convinced [15] that the solution of
differential task (2) meets to the solu tion ,ij
z
z
of an initial
task (1), the following assessment of speed of conver-
gence takes place
2
,12
||( )||,
hl
hli j
zz KhKl
2
 (26)
where – values of the exact decision a task (1) in
grid functions,
()
hl
z
hl
– spaces of net functions, || ||hl
is its norm and, 1
K
and 2
K
constants.
Theorem 4. Let in an inequality (26) 22
12
Kh Kl
,
and in game (13) from a “boundary” situation 0
(, )
N
f
f
0
(, )
N
yy
/(zx
completion of prosecution that is definitions 2
be possible. Then in game (1) fro m “boundary” situation
,)(,yzx)y

 , it is possible to
complete pursuit that are definitions 1.
(, )xy
4. Proof of Theorem
Proof of Theorem 1. Let 12 1
,,,
N

, i
Qi
,
1iN1
 – any sequence. Instead of inclusion (21) we
will consider other inclusion equivalent to it
11
11
111
(1)
(,
NN
NkNkN N
Nk NkNNNN
Q
zWk
P
1
)




 

Means, exists 1N
a
11
111
(, )
NN
NNkNkNNN
Q
aP
11
.
N



Such that
11
(1) .
NkNkN NN
zWk a
1

 

(27)
Now control of the pursuing player 1N
u, the relevant
control of the escaping player 1N
, we will construct as
the solution of the following control
1111
(, )
Nk NkNNNNN
ua
1
.

 
It is clear, that the equation has the decision. From
here owing to (27) we have
1
111
(1)(,)
NkNkN N
Nk NkNNNN
z
Wk u
 
 

11
 

We write down this inclusion in other look.
11 111
[(,)](1)
NkNkNNNNNN
zu Wk.

 

(28)
As a result from equalities (18) and (28) we will re-
ceive
1111
(1)
Nk NkNN
zWk



(29)
Done above a reasoning allow us to construct on the
set control 1N
providing inclusion (29). If now the
control 2N
becomes known that, we above can receive
in the stated way control 1N
u providing inclusion
1221
(2).
Nk NkNN
zWk



Repeating this process, further we can construct step
by step control i
u, proceeding from becoming known
controls i
, therefore, that in any step inclusion takes
place
111
(0).
Nk
zW


It means that
Copyright © 2013 SciRes. AJCM
M. Sh. MAMATOV ET AL.
60
1Nk
z
As we set out to prove.
Proof of Theorem 2. Let 121
,,,
N

, ii
Q
,
– any sequence. For concrete
1iN 11N
owing to
(22) and (23) we will receive inclusion
12
111
(1)
(, )
NkNkN N
Nk NkNNNN
zWk
P
 
1


 

(30)
Now as 1N
u we take that element from 1N
P
for
which inclusion (30) remained. Then we will receive
12
111
(1)
(, )
NkNkN N
Nk NkNNNN
zWk
u
 
1


 

From this it follows that
11 112
[(,)](
NkNkNN NNNN
zu Wk1).




And therefore, owing to (19) we have
1112
(1).
Nk NkNN
zWk



If now the control 1N
becomes the stated way
known that we above us can constru ct control 1N
u
pro-
viding inclusion
1222
(2).
Nk NkNN
zWk



Further arguing similarly in any step we will receive
12 1
(0) ,
Nk
zW


that is
1.
Nk
z

The theorem is proved completely.
Proof of Theorem 3. Instead of inclusion (25) mean-
ing (24) we will consider inclusion equiv a lent to it
1(()).
NkNkN N
zW
 


Existence
1
01 10
(),,,,0,1
k
kii
i
 
 
follows
from (24). From here follows
11
2
10
11
1111 1
[(,
[(,)
Nki Nki
NN
k
NkNkN N
iQ
iNkNki NkiNkiNki
kNkNNNN
Q
z
P
P
 










)]
].
(31)
Let now 12 1
,,,
N

, ii
Q
, – any se-
quence. Owing to (31) exists such that
1iN 
1N
a
1
11
111 11
2
10
11
[
[(
NN
Nki Nki
NkNkNNN
Q
k
NkNkN N
iQ
iNkNki NkiNkiNkiN
P
z
Pa

 








 
1
1
(,)],
,)]
N
(32)
Therefore, controls 1N
u we will construct as the so-
lution of the following equation
111111 1,11
(,), .
kNkNNNNNk
muam


 
Further owi n g t o (32) we have
2
10
11
11111,1
[(
(, ).
Nki Nki
k
NkNkN N
iQ
iNkNki NkiNkiNki
NkNN NNkk
z
P
um
 









,)]
It is equivalent to the fo llowing
11 1111,1
2
11
0
[(,)]
[(
Nki Nki
NkNkNN NNNNkk
k
iNkNki NkiNkiNki
Q
i
zu m
P
 


 
,)
 



Therefore owing to (32) we have
11111,1
2
11
0[(
Nki Nki
Nk NkNNkk
k
iNkNki NkiNkiNki
Q
i
zm
P
 



 


,)].
In the same way, if the control 2N
becomes the
stated way known that we above us can construct con-
trols 2N
u
providing inclusion
3
1 221122
0
11
[(,
NkiNki
k
Nk NkNNkkkkQ
i
iNkNki NkiNkiNki
zmm
P
 

)]






etc. Thus, we will receive
3
1 221122
0
11
[(,
NkiNki
k
Nk NkNNkkkk
Q
i
iNkNki NkiNkiNki
zmm
P
 

)]






from here we receive
1.
Nk
z

The theorem is proved completely.
Proof of Theorem 4. Let in game (13) one be able to
complete the pursuit from “boundary” situation
0
(, )
N
ff
0
(, )
N
yy
 in steps. Then, it follows from Defini-
tion 2 that from any sequence
N
01
, ,...,1
, ,
Nk
Q

0kN1,

of the evasion control it is possible to con-
struct a sequence 01 1
, ,...,,,
Nk
uuuu P
of
pursuit control such that the solution 01kN,
01 1
( ,,...,,)
NN
zzz z
of the equation 100
zXzy
0
, ,
11nnn
zzF

1n
nn
zA
1N
, 11
z
N
zX
NN
y
, for some hits dN:d
M
z
M
. Let now in game (2) (,),(, )xy Q xy

 
2()
, be
an arbitrary control of an evader from the class L
.
With the knowledge of the evader control (, )
x
y
, it
is possible to determine ,ik
as the values of this func-
tion at the node points of the grid , that is,
hl
1, 2,1,
( ,,...,).
kkk krk
 
Whence it follows that in virtue of Theorem 4 we can
construct the pursuer control in game (13) providing
completion of pursuit
1, 2,1,
( ,,...,).
kkkkrk
uu uuu
Now in game (2) we construct the pursuer control
(, )uuxy
as follows: ,,
(, ){:(1),
iki ki
uxyuuih xih
0,1,...,1,(1) ,0,1,...,1}irklyklk
 
uP
.
Obviously,
and 2
(, )()uxy L. By substituting
(,)
x
y
and (, )yuux
in (2), we obtain a differen-
Copyright © 2013 SciRes. AJCM
M. Sh. MAMATOV ET AL.
Copyright © 2013 SciRes. AJCM
61
[2] O. A. Ladyzhenskaya, V. A. Solonnikov and N. N.
Ural’tseva, “Lineinye I Kvazilineinye Uravneniya
Parabolicheskogo Tipa,” (Linear and Quasi linear Func-
tions of Parabolic Type), Moscow, Nauka, 1967.
tial equation. Similarly, by substitu ting ,ik
and ,ik
u in
(3), we obtain a grid equation approximating equation
(2).
Let ()
hl
z be the value of the exact solution corre-
sponding to the controls (, )
x
y
and (, )uuxy of
problem (2) at the nodes of the grid,
,
hli k
z be the solu-
tion corresponding to the controls ,ik
and ,ik
u of the
difference problem (3). Then, we obtain from (13) and
the condition of Theorem 4 that
[3] V. A. Il’in, “Boundary Control of String Oscillations at
One End with Other End Fixed, Provided that Finite En-
ergy Exists,” Dokl. Ross. Akad. Nauk, Vol. 378, No. 6,
2001, pp. 743-747.
[4] V. A. Il’in and V. V. Tikhomirov, “Wave Equation with
Boundary Control at Two Ends and Problem of Complate
Oscillation Damping ,” Diff. Uravn., Vol. 35, No. 5, 1999,
pp. 692-704.
2
,12
() .
hl
hli k
zz KlKh

From this fact and ,ik
zM1
, we obtain ,
() ,
hli k
zz S
,
() ,()
hli khl
zSzzSM

 [5] Yu. S. Osipov and S. P. Okhezin, “On the Theory of Dif-
ferential Games in Parabolic Systems,” Dokl. Akad. Nauk
SSSR, Vol. 226, No. 6, 1976, pp. 1267-1270.
1
n
, which proves the theorem.
5. Conclusions [6] F. L. Chernous’ko, “Bounded Controls in Distrib-
uted-parameter Systems,” Prikl. Mat. Mekh., Vol. 56, No.
5, 1992, pp. 810-826.
Thus, to solve the game problem of pursu it in th e fo r m (1)
we pass to the discrete game (13) or (14), and Theorems
1-3 establish the sufficient condition for such problems.
Theorem 4 establishes the sufficient conditions for solv-
ing the problem of pursuit (1). Here, the difference
(see Section 3) plays the main part in the solu-
tion of problem and implies that the solutions of the grid
equation (2) are stable.
,
()
hli j
zz
[7] N. Satimov and M. Sh. Mamatov, “On a Class of Linear
Differential and Discrete Games between Groups of Pur-
suers and Evaders,” Diff. Uravn., Vol. 26, No. 9, 1990, pp.
1541-1551.
[8] N. Satimov and M. Tukhtasinov, “On some Game Prob-
lems in the Distributed Controlled Systems,” Prikl. Mat.
Mekh., Vol. 69, No. 6, 2005, pp. 997-1003.
The problem of stability of the grid equation (2) lies in
determining the conditions under which the numerical
error tends to zero with growing j uni-
formly in all , or at least remains bounded.
,
()
ijhl ij
pz z
,0i
,
i
[9] N. Satimov and M. Tukhtasinov, “On some Game Prob-
lems in Controlled First-order Evolutionary Equations,”
Diff. Uravn., Vol. 41, No. 8, 2005, pp. 1114 -1121.
[10] M. Sh. Mamatov, “On the Theory of Differential Pursuit
Games in Distributed Parameter Systems,” Automatic
Control and Computer Sciences, Vol. 43, No. 1, 2009, pp.
1-8. doi:10.3103/S0146411609010015
Equation (2) is called stable if the round off errors
generated in the course of calculations have tendency to
decrease or at least not to increase. Otherwise, the accu-
mulated errors may reach a value such that the numerical
solution has nothing in common with the exact
solution of the grid problem (2). It goes without saying
that such unstable grid equations cannot be used for nu-
merical solution of the differential games.
()
hl
z
[11] M. Sh. Mamatov, “About Application of a Method of
Final Differences to the Decision a Prosecution Problem
in Systems with the Distributed Parameters,” Automation
and Remote Control, Vol. 70, No. 8, 2009, pp. 1376-1384.
doi:10.1134/S0005117909080104
[12] M. Tukhtasinov and M. Sh. Mamatov, “On Pursuit Prob-
lems in Controlled Distributed Systems,” Mathematical
notes, Vol. 84, No. 2, 2008, pp. 273-280.
Theorems 1-4 are easily generalized to a wider class of
differential games, for example, when
2
1212 12
2
1(,,...,)(( ,,...,),(,,...,))
n
nn
z
axxxfuxxx xxx
x
n
[13] M. Tukhtasinov and M. Sh. Mamatov, “About Transition
Problems in Operated Systems,” Diff. Uravn., Vol. 45,
No.3, 2009, pp. 1-6.
with discontinuous coefficients. [14] M. Sh. Mamatov and M. Tukhtasinov, “Pursuit Problem
in Distributed Control Systems,” Cybernetics and Systems
Analysis, Vol. 45, No. 2, 2009, pp. 297-302.
doi:10.1007/s10559-009-9100-x
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