*109489*

 

Yunicheva N.R., Yunicheva R.R

Institute  of Informatics and Control Problems, Kazakhstan

Al-Farabi Kazakh National University

The formal type of solving  parametrical synthesis task of  inexact data objects control

 

In article [1] it has been shown, that a task of parametrical synthesis of control by objects with inexact data it is reduced to resolvability of interval system of the linear algebraic equations. On the other hand, well-known, that the finding of the decision of such interval systems is NP – difficult task.

The review of references under the applied interval analysis reveals existing types of solving of similar systems.

The concept of "solving" of interval system of inclusions demands special specification since interval uncertainty of the data of system can be treated doubly, according to dual understanding of intervals [2].

In the first case, the interval  is set of all material numbers from  up to , and in the second - to contain in itself even one value between  and .

From the point of view of mathematics, this distinction is expressed by the use of quantifiers of universality  and quantifier of existence : in the first case enters the name , and in the second .

As to parameters of system of the linear interval equations about which the belonging to some intervals basic distinction between two types of interval uncertainty is shown as distinction between parameters which can change within the limits of the intervals specified by it as investigation of external unpredictable indignations and parameters with which we can vary within the limits of the set intervals at the will is known only i.e. to operate them.

In the interval analysis there are following various definitions of concepts of solving of interval system of the algebraic interval equations [2]:

The united solution set ,

,                          (1)

which is formed by decisions of all systems  with  and .

 The task of construction of set of a kind (2) can be named a task of identification.

Tolerlable solution set

,                                   (2)

which is formed by all such vectors , that product  gets in  for anyone .

The task of construction of set of a kind (2) refers to as a linear tolerance task. That fact is curious, that the initial motivation of introduction and studying äîïóñêîâûõ decisions has come from a task of designing of the elevating crane and a task of calculation of interbranch economic balance at the inexact data [2].

Controllable solution set

         ,                            (3)

educated by such vectors , that for anyone desirable  it is possible to pick up corresponding  satisfying .

The task of construction of set of a kind (3) is a task of control. Controllable solution set for the first time have been entered by Shary [2].

Formal decisions (them still name "algebraic") for the first time have been entered in [3]. The description and calculation of formal decisions of interval linear systems rather difficult process, however dot formal decisions are deprived similar difficulties.

In article the formal type of the decision of the above-stated interval systems is considered. The computing algorithm is developed.

 As it has been marked, the task in view is shown to resolvability of system of linear interval algebraic inclusions:

 

                                                                 (4)

 

where - the interval matrix made of elements of a matrix  and a vector  of object of management;  - the interval vector made of factors at the corresponding degree  of a characteristic polynom of object of management;  - the interval vector made of factors at the corresponding degree  of a desirable characteristic polynom of the closed control system [4].

The interval vector refers to as the formal decision of system if his substitution in this system and performance of all operations by rules of interval mathematics results in true equality.

Further we shall allocate the dot formal decision which satisfies to the following equation:

                                                 (5)

 

Let's prove, that the vector is the dot formal decision of system in only case when it satisfies to system of the following kind:

 

                                          ,                                                   (6)

where ,  medial matrixes; ,

 

                                             ,                                                  (7)

where  always a non-negative matrix of radiuses ;  always a non-negative vector of radiuses .

Under the offer [5] system (2) is equivalent to below-mentioned system.

 

,                            (8)

 

That attracts (6), (7). However, on the other hand, from system (6), (7) follows (8) and therefore, follows (5).

According to the theorem from [5] vector is the dot formal decision of system in only case when it is as äîïóñêîâûì, and its controlled decision. If the matrix  is nonexceptional the system  has the dot formal decision in only case when  these data satisfy to the following system

                                                    (9)

 

and in this case the vector  is unique such decision.

 

References

1.      Yunicheva N.R. Questions of the analysis and synthesis of control systems by objects in  uncertainty conditions. Almaty, Printing house «Ñlassics». 2011. –95p.

2.      Shary S.P. Solving the linear interval tolerance problem // Math.Comput. Simulation. 1995. V.39.–P.53-85.

3.      Jolen  L., Kiefer Ì., Didri Î. Walter E.. The applied interval analysis. M.: Institute of computer researches. 2007. – 467p.

4.      Khlebalin N.A. Modal Control of Plants with Uncertain Interval Parameters, in: Proc. Intern. Workshop «Control System Syntesis: Theory and Application», Novosibirsk, 1991. -P. 168-173.

5.      Fiedler M., Nedoma J, Ramik J., Rohn J., Zimmerman K. Linear optimization problems with inexact data M.: Institute of computer researches. 2008. – 288p.