scholarly journals Self-Oscillations of The Free Turbine Speed in Testing Turboshaft Engine with Hydraulic Dynamometer

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 114
Author(s):  
Oleksandr Lytviak ◽  
Vasyl Loginov ◽  
Sergii Komar ◽  
Yevhen Martseniuk
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Control Laws ◽  
Automatic Control Systems ◽  
First Case ◽  
Calculation Results ◽  
Nonlinear Features ◽  
Turbine Speed ◽  
Turboshaft Engine ◽  
Helicopter Main Rotor

Self-oscillations are one of the common problems in the complex automatic system, that can occur due to the features of the workflow and the design of the governor. The development of digital control systems has made it possible to damp self-oscillations by applying complex control laws. However, for hydromechanical systems, such way is unacceptable due to the design complexity and the governor cost. The objective of this work is to determine the parameters of the hydromechanical free turbine speed controller, ensuring the absence of self-oscillations during ground tests of the turboshaft engine with a hydraulic dynamometer. The TV3-117VM engine (Ukraine) with the NR-3VM regulator pump (Ukraine) was selected as the object of the study. However, self-oscillations can also occur in any modifications of the TV3-117 engine with any NR-3 regulator pump. The results of the research may be of interest to engineers and scientists who investigate the dynamics of automatic control systems for similar engines. The paper analyses the nonlinear features of the empirical characteristics of the FTSC leading to self-oscillations of the engine speed. The authors propose the mathematical model of the automatic control system dynamics, which takes into account all the features of the engine and regulator pump. It is shown that the load characteristics of the water brake and the helicopter main rotor can differ significantly. Research of the dynamic characteristics of the TV3-117VM engine was carried out. The analysis showed a good agreement between the calculation results and the field test results, and made it possible to determine the parameters of the controller, which lead to self-oscillations during test. Two cases are considered. The first case includes ground tests of the engine with a water brake; the second case—flight tests of the engine as part of the helicopter’s power plant. The data obtained make it possible to develop recommendations for adjusting the hydromechanical governor without testing it on the engine.

scholarly journals ALGORITHM FOR SYNTHESIZING PARAMETERS OF CONTROL LAWS OF TECHNICAL SYSTEMS UNDER POLYNOMIAL APPROXIMATION OF NONLINEARITIES

2018 ◽  
pp. 97-102
Author(s):  
V. F. Shishlakov ◽  
E. Yu. Vataeva ◽  
I. G. Krivolapchuk ◽  
N. V. Reshetnikova
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Polynomial Approximation ◽  
Nonlinear Characteristics ◽  
Control Laws ◽  
Software Complex ◽  
Automatic Control Systems ◽  
New Class ◽  
Advantages And Disadvantages ◽  
Direct Variational Method

The paper considers the algorithm for solving the problem of synthesis of automatic control systems (ACS) with nonlinear characteristics for polynomial approximation. As a mathematical apparatus, the inversion of the direct variational method of analysis, Galerkin generalized method, is applied to the solution of the problem. Recurrence relations are obtained that make it possible to extend this method to a new class of dynamical systems with nonlinear elements whose characteristics are approximated polynomially. The advantages and disadvantages of various methods of approximation of automatic control systems with nonlinear characteristics are analyzed. The presented algorithm of the software complex is universal and allows solving the synthesis problem for control systems of different classes and structures from unified mathematical, methodological and algorithmic positions.

COMPARISON OF CYBER CRIME AWARENESS AMONG SCIENCE AND SOCIAL SCIENCE PERSPECTIVE TEACHERS

2017 ◽  
Vol 4 (36) ◽  
Author(s):  
Anupam Bansal
Keyword(s):  
Social Science ◽  
Automatic Control ◽  
Control Systems ◽  
Child Pornography ◽  
Cyber Crime ◽  
Computer Data ◽  
Automatic Control Systems ◽  
Living Things ◽  
Wide Range

“Cyber crime” has been used to describe a wide range of offences, including offences against computer data and systems (such as “Hacking”), computer related forgery and fraud (such as “phishing”), content offences (such as disseminating child pornography), and copyright offences (such as the dissemination of pirated content). The word “Cyber Crime” has been derived from the words “Cybernetic” which means the science of communication and automatic control systems in both machines and living things.

Automatic Control Systems for Construction Machinery

1988 ◽  
Author(s):  
Makoto Kakuzen ◽  
Hirokazu Araya ◽  
Nobuo Kimura ◽  
Isao Sawamura
Keyword(s):  
Automatic Control ◽  
Control Systems ◽  
Construction Machinery ◽  
Automatic Control Systems
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