CSITA AUTOMATION
ISSN 2414-9055
© Computer science, information technology, automation. 2018. Volume 4, issue 3
27
UDC 681.5:622.2 https://doi.org/10.31721/2414-9055.2018.4.3.27
ADAPTIVE CONTROL AND IDENTIFICATION OF DRILLING SYSTEM
WITH CONSIDERING THE TYPE OF DRILLED ORE MATERIAL
Morkun V.S., ScD, Professor,
Tron V.V., PhD, Associate Professor,
Paranyuk D.I., MS
Kryvyi Rih National University
Abstract: The object is to investigate methods for forming a model for the system of adaptive control over drilling with the con-
trol object identifier.
The following methods have been used in the course of the research: analysis of domestic and foreign experience,
systematization of available approaches and methods, methods of numerical simulation for synthesis and analysis of mathematical
model, methods of mathematical statistics and probability theory for processing the results of experiments, methods of analytical
design and computer simulation in the synthesis and analysis of control system, methods of system analysis in the development of
control algorithms.
The scientific novelty consists in determining optimal parameters – number of membership functions, membership function type,
inputs number - for neuro-fuzzy subsystem of drilling control system with considering the type of drilled ore material.
The practical significance of the studies is a structure of adaptive control and identification of drilling system with considering
the type of drilled ore material including model of geological structure.
The results of the research investigate a strategy of the two-level adaptive control of borehole drilling under rapidly changing
conditions which implies simultaneous drilling investigation and control. The subsystem of prediction is implemented on the basis of an
adaptive neuro-fuzzy system. The applied neuro-fuzzy system realizes the Sugeno fuzzy inference in the form of a five-layer neural
network of signal feedforward, the first layer of which contains the terms of input variables (the current signal value and its delayed
values). It should be noted that the membership function type did not influence much on the prediction result. While processing and
analyzing the current information about the latest characteristics of drilling and while forming the adaptive control it is reasonable to
apply neurofuzzy structures with Gaussian membership functions.
Key words: drilling automation, neuro-fuzzy model, adaptive control.
Introduction. The creation of control for an
object with uncertain parameters is an important
problem of the automatic control theory.
Nonstationary and uncertain parameters of control
objects cause the necessity to create regulators
with adaptable parameters ensuring the
unchanged accuracy and quality of a system. The
creation of the adaptive system with an identifier
is aimed at forming a model-identifier of a control
object on the basis of fuzzy and incomplete
information [1].
Materials and methods
1. Analysis of research and publications
The quality of automatic control over
technological processes on various stages of iron
ore mining and processing can be improved by
using the latest information about the
technological process while controlling it [2-6, 12-
15]. In this case, the information on the
technological process development can be
obtained both by its direct measurement and by
using a mathematical model [2].
As drilling characteristics are random and
non-stationary it is reasonable to apply the
methods of adaptive control with an identifier of
an object model while synthesizing this process
control. The research is aimed at investigating the
methods of forming a model for the system of
adaptive control over drilling with the control
object identifier [7]. In general, when forming the
adaptive control of drilling rocks one should
consider the fact that the control object is under
the influence of the following input impacts:
driving X
*
(t), controlling U(t) and disturbing Z(t).
The object’s behaviour characterized by the output
variables Y(t) depends on a set of unknown
parameters ξ with the given set of admissible
values Ξ among which one should distinguish
physical and mechanical characteristics of rock
types. In this case, it is necessary to form the
control that would ensure the given indices of
drilling quality under all admissible values of the
unknown parameters ξ.