RESEARCH ARTICLE

Scenario approach to the engineering of informationmodels, designed to enable the activities of operator

in automated control systems

M.A. Pavlenko, A.I. Tymochko, V.N. Rudenko, P.G. Berdnyk, A.S.Shevchenko

Automated control systems department, Kharkov university of Air Forces,Kharkov, Ukraine

Email: M.A. Pavlenko bpgpma@list.ru 77/79 Sumskaya str., Kharkov,Ukraine

Scenario approach to the engineering of information models, designed to enable the activities of operator in automated control systems

The article deals with the problems of designing and development ofinformation models system for data support of activities of air

traffic operator in automated control system. The generalized analysisof operator’s activities is conducted, the assessment of time

expenditure for the fulfillment of different actions, concerned withthe analysis of information models, is described, and the set of

standard actions under different conditions of current air environmentis selected. The selection of standard actions of the operator allowsto form the algorithms or scenerios of his behavior, what, in its

turn, serves as a basis for the engineering of information models. Theapplication of intellectual information technologies enables to solvethe task of current situation recognition and implement the synthesisand control procedure of information models. The use of operator’s

behavior scenario can improve the quality of data support engineeringand provide the increase of operator’s activities efficiency.

Key words: operator; information model; control; ergonomicengineering; operator’s activities; decision making; scenarioengineering.

Introduction. In order to understand clearly notions anddefinitions used in the article, the notion “information model”is to be specified in the context introduced in the article.Information model (IM) is semantic or syntax description

performed in the view of images. The description reflectsproperties, specifics and relations of the object observed (orthe process, feature, system, situation, etc.). The informationmodel is realized by means of display devices complex, whichincludes a complex of data displaying technical equipment aswell as software implementation of information processingalgorithms. The information model is a constituent of theinformation system in automated control systems (ACS). Let’s study the process of air traffic control on the grounds

of dispatcher’s behavior (hereinafter referred to as “operator”)in airway traffic control center.Operator’s behavior model while solving the task of air object

(AO) location definition, numerical strength, flight line, speedand altitude envelope can be represented by the following graph(Figure 1) [1, 10].

*Email: M.A. Pavlenko ergonomal@gmail.ru

Points of the presented graph correspond to the certain events(for instance “information, presented by display devices, isacquired”, “input of commands into ACS is fulfilled”, meanwhilegraph edges are the probabilities of transition from one event

Figure 1. Operator’s behavior model while analyzing air environment.

to another, as well as time, spent for such transition. Thecontent of the present graph points as well as the meaning andsequence of transitions between those points are shown in Tables1, 2.

Table 1. Events Event content

1 Start of operator’s work with control panel 2,3 Operator’s interaction with other people in the shift

4 Analysis of information, presented on a large screen, is acquired

5 Analysis of general information, presented on automatedworking station screen, is acquired

6 Analysis of summarized information on automated workingstation screen is acquired

7 Analysis of information presented by IM is acquired8 Information input from keyboard is done9 Information input using mouse pointing device is done

10 Additional information from tablets and display panels is accepted

11 Assessment of the information about air environment is fulfilled

12 No decision13 Decision is made14 Confirmation button is pressed 15 Task is solved

Table 2. Transitio

nsOperator’s behavior while transiting from one event to another

4,1 5,1 6,1, ,w w w Sensing by the operator of the information on a large screen and automated working station screen

10,1wSensing by the operator of the information presented with the help of tablets and display panels

11,12 11,13,w w Decision making13,14w Confirmation of decision making command 14,15w Finishing of task solving

The model studied can be technically set as follows [1]:

ijP p (1)

ijT t (2)

where P - transitions probability matrix between events ij ;T - matrix of time, spent for the operation, while transitingfrom event i to event j ;

ijp - transition probability from event i to event j ;ijt - time, spent for transition from event i to event j ;

i j N - and corresponds to the quantity of positions that canbe possessed by the operator.

ijp and ijt values are set as

ijw , where ,ij ij ijw p t in Figure 1.

The analysis of the present model using simulation tools [1]allows to define time expenditure for execution of certainoperations, time expenditure for execution of the complex ofoperations concerned with different aspects of operator’sbehavior (work with automated working station (AWS), commandsentry, etc.) as well as to conduct the analysis of hisactivities depending on used IM.

The researches of operator’s behavior reveal that thestructure and the properties of used IMs significantly influencethe quality and the efficiency of operator’s activities [2 - 6].Present influence becomes greater when operator’s behavior isstudied in different substandard situations. Such situations canbe as follows: flight procedures violation, intruding aircrafts,flight of unidentified object, etc.

Thus, the conduction of further researches on the improvementof IM considering the peculiarities of operator’s behavior indifferent conditions of the environment is immensely needed.

Literature review. A wide range of works [1, 2 - 6] isdedicated to the investigation of methods of IM development andcontrol during the arrangement of data support of controlproblems solving. Provided that, different types of informationmodels and methods of their development are described. The basicof them are the following:

1. Text IMs [2, 3] are used for displaying the staticalinformation. A principal mission of such ordinary informationmodels is to display statical text data necessary within the

process of operator’s activities. Instruction manuals, operatingprocedures, active tasks lists, etc., which are represented tothe operator in a form of text documents, can be deemed as anexample of such IMs.

2. Algorithmic methods of IM development and control [3, 4]allow to form models, which display the algorithm of operator’sactivities. They can be divided into information-logical andcommand-data ones. These models are applied to control onecompound object, e.g. power-generating unit, nuclear reactor,etc.

3. After the manner of information displaying and appliedmethod of IM control can be distinguished [4-6] the next ones:graphic approach to data displaying with no concern ofoperator’s behavior algorithm and graphic approach to datadisplaying with constrained concern of operator’s behavioralgorithm. The disadvantages of the first method are: IMdisplays the information necessary for solving of only one ortwo control tasks; displayed information does not correspond tothe logic of operator’s behavior; the analysis of the modelrequires considerable time loses.

4. IM control method, based on a graphic approach to datadisplaying with constrained concern of operator’s behavioralgorithm [2-6], allows to develop more advanced IMs. Thedisadvantages of the method are: restricted number of IM controlprograms; the lack of realization of immediate situationdetection support; the lack of possibility of IM displayingparameters adaptable control; operator’s behavior support isfulfilled with constrained set of control-problem algorithms.

Thus, issues, concerned with the buildup of IMs developmentand control methods, that could make possible the control of IMwith taking into account the current situation and in accordancewith tasks, solved by the operator while implementing airtraffic control, are incompletely studied and described in theliterature and require the further researches. The developmentof IM control methods with consideration of the statedrequirements is possible if using intelligent method ofinformational criteria choice and modifying IM data items inaccordance with the current environment and tasks, solved by theoperator.

Main body. The analysis of the literature enables to take upthe position that the further prospect of IM development andcontrol methods elaboration is the use of intelligent methods.

However, the implementation of such an approach is possible interms of immediate identification task solving of the situationsoccurring in the air area. Currently, there is one approach,which allows to solve this task [7-9], is described. Still, it’suse causes the necessity to develop the multitude of IMs anddata items, which could help to represent the variety ofsituations occurring in the air area and their peculiarities.

Mathematically such task can be formulated as follows. Thereis a multitude of informational criteria (IC) iu , describing apotential situation, which is to be represented in a view of Umultitude. This IC multitude can be introduced as:

ii

u U . (1)

Herewith, the variety of different situations, occurring inthe air area n Lk А can be singled out. A definite nU multitudeif IC criteria, characterizing the situation, can be assigned toevery situation of that kind:

i ni n

u ku U

, n

nU U . (2)

To every situation nk can be assigned onП multitude, defining

IC oju :

,oj n

o o oj n n n

u ku П П U

. (3)

There are IC, characterizing nk in detail and indicating one oranother their peculiarities, assigned to each from nk situations(except o

ju ) in multitude U. Let’s call such IC as additional[9] and denote them by д

ju . To nk can be assigned д

nП multitude ofдju informational criteria:

д

д д,j n

дj n n n

u ku U

(4)

During the ergonomic engineering of IMs and their fragmentsalong with informational criteria д

nП it is necessary to definemissing IC. These IC are formed on the grounds of source dataprocessing. Let’s denote such IC by *

ju . Thereafter, *nП multitude

is to be figured:

*

* * *,j n

j n j nu k

u u U

. (5)

Thus, the structure of IC, representing the current situation,can be proposed as follows:

*o дn n n nП П П U . (6)

The list of tasks, solved by the operator in a definitesituation, must also be taken into account in order to form IMsituation evaluation. Z-multitude of all mz tasks during thesituation evaluation can be presented in the following view:

mm

z Z . (7)

Then, nk multitude of situation evaluation tasks can be shownas:

,m n

m n nz k

z Z Z Z

. (8)

The analysis of situation evaluation tasks allows to definethe appropriate structure of IC for solving the present tasks.The multitude W of necessary mz

gW IC for solving mz tasks:

,m m

g m

z zg g g

w zw W W W

. (9)

Herewith, it should be noted that there is a probability ofoccurrence of the situation when mz

gW will contain IC from

multitudes *, ,o дn n nП П П :

* mzo дn n n gП П П W . (10)

This causes the necessity to search (obtain) for theadditional information as well as to make provision for presentfactor while engineering the IM in such a way, that operator’sintellectual activity with self-sufficient defining of missingIC (on the basis of information, displayed in IM) will beprovided.Formalistic specifying of appropriate IC selection procedures

for IM development can be shown as a set of morphisms,formalizing the procedures of their selection.

Let’s extract the set of situations to which can be

defined as the multitude of solved by the operator tasks ( nZ ) inthe current situation nk by virtue of situation recognitionprocedures analysis [9]:

1:m n

n nz kk Z

. (11)

Considering the obtained list of solved tasks evaluation nZlet’s find the multitude of IC, which provide their solving:

1: n

i n

Zgu Z

f U W . (12)

Hereafter, it is required to choose defining oju , additional д

ju, and

auxiliary *

ju IC needed to solve tasks

nZ . Technically

these procedures are to be set as:

2: nZo nj g

o oj Z

u Wf u П

; (13)3: nZд nj g

д дj Z

u Wf u П

; (14)*

* *4: nZnj g

j Zu W

f u П

. (15)

Lots of general IC, providing the background, where can beseen the rest of IC, is separated in order to solve

nZ tasks.

For that purpose must be distinguished the set of statical IC1 2{ , ,..., },d dS s s s s U :

dd

s Us S

. (16)

Then, to solve nZ tasks it is necessary to separate themultitude nZ

nS of IC ds , providing their solving:

5: n

d

Zd ns S

f s S

. (17)

Therefore, IM, providing data support of nZ task solving under

conditions of nk , can be presented in a form of the following IMn

multitude:

* nn n n

Zo дZ Z Z n nП П П S ИМ . (18)

Four groups of IM are distinguished to form IM: defining group: represents specific characteristics of the

situation and allow to fulfill the assessment in whole, definesits belongment to a definite class;

additional group: characterizes the details of thesituation, presents it’s peculiarities for solving specifictasks in the current conditions;

auxiliary group: displays the information about the IC, whosedata are received on the grounds of supplementary analysis andconversion, defining auxiliary IC as well as those IC, thatcan’t be obtained clearly;

static group: characterizes the static data, assisting whilesolving specific task of the current situation assessment. Thedevelopment of IM structure is to be conducted on the basis ofIC choice stages, stated above. Not all the available IC are used during the formation of base

IM, but only those that possess minimum combination and providethe understanding of the current situation by the operator.

After the modification of n

oZП

enacts the modification of IM

from base IM (BIM) to BIM1.This process can be displayed in a form of the graph, whose

points are the type of reflected IM and branches are thetransitions from one IM to another (pic. 2).After defining the character and IC change scope the final

structure of IM is formed. The example of IM structure ispresented in Figure 2.

Figure 2. The example of IM structure.

However, such quite a general approach to the process of IMdevelopment and control possesses one substantial disadvantage.It can be characterized as uncontrollable growth of possible IMnumber and the absence of adequate information richness controlfacilities of such IMs. The present approach does not allow toassert the fact of ability to get the IMs, which aresatisfactory for the situations and peculiarities of operator’sbehavior.

What can be the factor, holding down the growth of IMsquantity? The answer for this question is hidden in the operatorhimself and the nature of his activities. The operator’sbehavior on air traffic control is proceduralized by the greatnumber of documents. To these documents belong the followingones: airspace management law, guidelines, rules, etc. Thecontrol process is also influenced by the type andcharacteristics of air objects as well as the conditions of thecurrent situation.

Thus, it is necessary to reconsider the approach to therealization of IM synthesis and control process in order to keepa check on the current air environment. Herewith, the currentsituation is to be a key determinant for all actions of theoperator. In this case his behavior won’t be disordered; indeedit will conform to the rules and algorithms, specific to thegiven situation. For instance, in case when it is need toprevent aircrafts collision the operator is going to solve thetask in restricted area of environment and he will not supervisethose objects which possess no threat.

Consequently, it is reasonable to assume that the operatormust act on the grounds of pre-arranged scenario (algorithm),formulated for all possible situations. In this case, the wholeprocess of his activities can be presented in a form of the setof scenerios and transitions between them.

So, considering Figure 2 and the singled out scenerios, thequantity of IMs can be restricted, and their relations can beidentified in accordance with possible situations. The exampleof suchlike set of scenerios, possible transitions and used IMsis represented in Figure 3.

Figure 3. The structure of IMs, providing data support of operator’s behavior.

Thus, a new approach to the designing of data support systemof operator’s behavior on air traffic control is offered in thearticle. We shall call the present approach as scenarioengineering of operator’s behavior data support system. The

BIM(Standard situation)

BIM +Violation of airspace

managementrules

BIM + Frontier

infringement

BIM +Flying over

forbidden zones

BIM + Approach to forbidden

objects

scenario engineering of operator’s behavior data support system should beunderstood as the process of the development of operator’sbehavior data support systems, which is based on scenariosanalysis results of his activities in current environment(situations).

Each situation should be described by own informationcriteria, which will characterize it uniquely. This will help toavoid user’s information overloading, simplify the process of IMdynamic synthesis and control.

To solve the task of IM control and prevention of operator’sinformation overloading, the mandatory requirement of successfulfunctioning of such system is the development of currentsituations recognition system.

Certainly, the question “what should be done if thesituation, which doesn’t conform to any of described in thesystem, appears?” can arise. This question always arises in caseof intellectual systems use. The conducted researches with theuse of situations recognition system reveal [7-9], that theabsence of new situation description in knowledge base leads tothe error of identification. But in practice such situation israrely appears unexpectedly. It comes up during the transformingfrom already known situations and rarely can disorientate theoperator.

The other side of the question is that the operator hasn’tgot well-defined protocol of actions in such conditions, so theIM control system switches to a mode of general IM displaying.This mode corresponds to a base information model. Thecorresponding report emerges in supplementary display devices orthe parts of the screen, designated for displaying of additionalinformation, to show the data on features of the situation orappearing threats.

Conclusions. The approach to the development of informationmodels system for the information support of operator’sactivities on air traffic control is suggested in the article.Main features, taken as a basis of the offered approach, are:

(1) Use of intellectual technologies of IM synthesis andcontrol; (2) Accommodation of background research and modeling ofoperator’s behavior;(3) Revelation of specific scenerios of operator’sactivities; (4) Comparison of behavior situations and scenerios;

(5) Engineering of IMs, which correspond to operator’sbehavior scenerios.

Such an approach to IM engineering is caused by the fact thatoperators of air traffic control are obliged to work inconditions of dynamic change of the current situation.Environment change dynamics can be characterized as high andvery high. It is also should be noted that the air trafficcontrol system is an open-end system and can be affected by lotsof factors: from technical to political. Under such conditionsthe use of mature methodologies for IM development can lead touncontrollable information overloads and lowering of theeffectiveness of operator’s activities. Application of theproposed method allows to restrict the number of IMs, conducttheir setting and adjustment as well as to provide the operatorwith the supplementary information in case of unpredictablechange of the current situation. The use of intellectualtechnologies can help to realize mechanisms of the best practiceaccumulation and relatively easily modify synthesis and controlsystem without the necessity to rework system in whole.

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