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PRACTICAL WORK №3

THE ACTIVITIES OF HUMAN-OPERATOR

1 OUTCOMES
Become familiar with the peculiarities of the system “Human – Machine”
and learn to identify its basic parameters

2 DURATION OF CLASS
The class duration is four academic hours

3 BASIC THEORY
One of the parameters that characterize the interaction of an operator with a
machine is determined by the time, which is necessary for receiving, processing
and transmitting of the information. The time that an operator spent for the search
of the desired object can be found through the formulation:
n
t i .s .   t f i  t m i  , (3.1)
і  1
where n – number of eyesight fixations in the search;
t – time of visual fixations during the search, s;
f i
t – time to i-th moving of eyesight, s;
m і
The time of signal delay by an operator is given by:
m
k
k

,
t
Т о    n i    n i   t m i n i t id (3.2)
i
i
1  і 1  і 1  і
where k – number of devices;
Δt – time for assessment of device showings, s;
і
Δτ – time of transference of a look from one device to another, s;
і
t – duration of involuntary distraction of the operator, s;
id
t – time required to perform actions related to controlling the machine, s;
mі
m – number of regulators;
i
n – number of observations or switchings.
i
If the queue of signals is available the operator does not immediately begin
processing the signal. In this case, the time of expectation for service of the signal
is the time t , and the speed of operator is characterized by the time of stay of
ex.
information during servicing t stay :
t stay  t pr  t ex , (3.3)
where t – time, which is required for signal processing.
pr
The required speed is determined by the duration of the cycle management
(T ):
c
n
,
t
Т c   і  t stay (3.4)
і  1
where t – signal delay time by i-th machine mechanism.
і

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