scholarly journals Development of Algorithms for Identifying Parameters of the Maritime Vessel Motion Model in Operating Conditions with Elements of Intellectual Analysis

2021 ◽  
Vol 9 (4) ◽  
pp. 418
Author(s):  
Nikolay Ivanovskii ◽  
Sergei G. Chernyi ◽  
Anton Zhilenkov ◽  
Vitalii Emelianov
Keyword(s):  
Control Systems ◽  
Field Tests ◽  
Operating Conditions ◽  
Random Parameters ◽  
Unknown Parameters ◽  
Motion Models ◽  
Real Time Scale ◽  
Ship Control ◽  
Measured Information ◽  
Vessel Motion

The article examines the synthesis of algorithms for the estimation of the random parameters of ship movement models, based on measured information in field tests. In addition, accuracy analysis of the synthesized algorithms is provided. The derived algorithms are relatively simple and allow highly precise unknown parameters for estimation of ship motion models at the non-real-time scale to be obtained using the measurements recorded in field tests. The results can be used in the construction of automated ship control systems, or in the development of navigation simulators and the creation of ship models.

Combining Physics-Based and Data-Driven Models for Estimation of WOB During Ultra-Deep Ocean Drilling

2018 ◽  
Author(s):  
Tatsuya Kaneko ◽  
Ryota Wada ◽  
Masahiko Ozaki ◽  
Tomoya Inoue
Keyword(s):  
Hybrid Model ◽  
Numerical Models ◽  
Drill String ◽  
Operating Conditions ◽  
Data Driven ◽  
High Frequency Oscillation ◽  
Lumped Mass ◽  
Unknown Parameters ◽  
Mass Model ◽  
Time Operation

Offshore drilling with drill string over 10,000m long has many technical challenges. Among them, the challenge to control the weight on bit (WOB) between a certain range is inevitable for the integrity of drill pipes and the efficiency of the drilling operation. Since WOB cannot be monitored directly during drilling, the tension at the top of the drill string is used as an indicator of the WOB. However, WOB and the surface measured tension are known to show different features. The deviation among the two is due to the dynamic longitudinal behavior of the drill string, which becomes stronger as the drill string gets longer and more elastic. One feature of the difference is related to the occurrence of high-frequency oscillation. We have analyzed the longitudinal behavior of drill string with lumped-mass model and captured the descriptive behavior of such phenomena. However, such physics-based models are not sufficient for real-time operation. There are many unknown parameters that need to be tuned to fit the actual operating conditions. In addition, the huge and complex drilling system will have non-linear behavior, especially near the drilling annulus. These features will only be captured in the data obtained during operation. The proposed hybrid model is a combination of physics-based models and data-driven models. The basic idea is to utilize data-driven techniques to integrate the obtained data during operation into the physics-based model. There are many options on how far we integrate the data-driven techniques to the physics-based model. For example, we have been successful in estimating the WOB from the surface measured tension and the displacement of the drill string top with only recurrent neural networks (RNNs), provided we have enough data of WOB. Lack of WOB measurement cannot be avoided, so the amount of data needs to be increased by utilizing results from physics-based numerical models. The aim of the research is to find a good combination of the two models. In this paper, we will discuss several hybrid model configurations and its performance.

Prevention of Low-Frequency Vibration of High-Capacity Steam Turbine Units

1997 ◽  
Author(s):  
H. Kanki ◽  
Y. Kaneko ◽  
M. Kurosawa ◽  
T. Yamamoto ◽  
Y. Yamamoto ◽  
...  
Keyword(s):  
High Pressure ◽  
High Capacity ◽  
Low Frequency ◽  
Field Tests ◽  
Operating Conditions ◽  
Squeeze Film ◽  
High Pressure Turbine ◽  
Solution Approach ◽  
Vibration Excitation ◽  
Low Frequency Vibration

Abstract The causes of low-frequency vibration (subsynchronous vibration) of a high pressure turbine were investigated analytically and also via vibration excitation tests on actual machines under operation. From the results, it was concluded that low-frequency vibrations may be caused by either the decrease of the rotor system damping or by external forces, such as flow disturbance in the control stage and the rubbing between the rotor and casing. After identifying the cause of the low-frequency vibration, appropriate countermeasures such as installation of a squeeze-film damper and modification of valve opening sequence were taken. Vibration measurements and vibration excitation tests for the high pressure turbine under actual operating conditions were carried out in order to verify the validity of the countermeasures. These field tests confirmed that the problems of low-frequency vibration can be solved completely by taking the appropriate countermeasure depending on the cause of the vibration. This paper presents some field experiences of low-frequency vibration and the effective solution approach.

Recent Technological Advances in the Control and Guidance of Ships

1994 ◽  
Vol 47 (2) ◽  
pp. 236-258 ◽  
Author(s):  
N. A. J. Witt ◽  
R. Sutton ◽  
K. M. Miller
Keyword(s):  
Control Systems ◽  
Intelligent Control ◽  
Adaptive Systems ◽  
Control Method ◽  
Control Strategies ◽  
The Past ◽  
Technological Advances ◽  
Ship Control ◽  
Made In ◽  
Modern Control

Over the past seventy years many advances have been made in the field of ship control. Early developments by Sperry and Minorsky on proportional controllers have led to today's modern control systems which have interfacing capabilities with position fixing equipment.This paper presents a brief historical summary of the methods employed in ship control from early proportional devices through the range of adaptive systems and concludes with details of a possible future control method known as intelligent control.Intelligent control consists of three methodologies: expert, fuzzy and neural. An investigation and comparison of the methodologies will present possible future control strategies.

scholarly journals Synthesis of random parameter identification algorithms and estimates of current vessel motion parameters

2020 ◽  
Vol 164 ◽  
pp. 03004
Author(s):  
Nikolay Ivanovskiy ◽  
Ivan Gorychev ◽  
Aleksandr Yashin ◽  
Sergey Bidenko
Keyword(s):  
Angular Velocity ◽  
Parameter Identification ◽  
Real Time ◽  
Angular Position ◽  
Random Parameter ◽  
Moment Of Inertia ◽  
Position Vector ◽  
Random Parameters ◽  
Motion Parameters ◽  
Vessel Motion

The paper considers the task of synthesis of algorithms for identifying random parameters of a vessel, such as attached masses, moment of inertia, and estimating the current parameters of the vessel's motion from real-time measurements of onboard sensors. The task of the synthesis of algorithms for identifying random parameters of the vessel and evaluating the characteristics of the vessel’s movement is to determine (evaluate) the current parameters (attached masses, moment of inertia) and the characteristics of the vessel’s motion (position vector, speed) from the measurements of the vessel’s motion, angular position and angular velocity of the vessel rotation).

A Hydroelectric Plant Simulation Model to Test the Performance of Actual Governor Control Systems

2008 ◽  
Author(s):  
Iva´n F. Galindo-Garci´a ◽  
Antonio Tavira-Mondrago´n ◽  
Sau´l Rodri´guez-Lozano
Keyword(s):  
Power Plant ◽  
Simulation Model ◽  
Control Systems ◽  
Real Time ◽  
Hydraulic System ◽  
Hydroelectric Plant ◽  
Field Tests ◽  
Hydroelectric Power Plant ◽  
Hydroelectric Power ◽  
Surge Tank

A simulation model of the hydraulic system of a hydroelectric power plant is developed and implemented in a real time simulator. The main purpose of the simulator is to test the performance of actual governor control systems using hardware-in-the-loop techniques, in which the actual governor control system is connected to a real time simulator instead of being connected to real equipment. This paper focuses on the modeling of the hydraulic system to be implemented in the simulator. The model consists of an unrestricted reservoir, conduits to transport water, and a turbine to convert the potential energy of the fluid into mechanical power. A nonlinear mathematical model for a non-elastic water column is implemented. Effects due to a surge tank and to various turbines connected to a common tunnel are included in the model by considering head and flow variations at the junction of the common tunnel and the individual penstocks. The model is evaluated by comparing results from simulations with field tests from a four-unit hydroelectric power plant (55 MW per unit). Comparisons show that the model reproduces the general behavior of the field tests. However some deviations are observed during the transient response, in particular the simulation results appear to respond faster than field data.

scholarly journals Hardware in the Loop Platform for Testing Photovoltaic System Control

2020 ◽  
Vol 10 (23) ◽  
pp. 8690
Author(s):  
Víctor Samano-Ortega ◽  
Alfredo Padilla-Medina ◽  
Micael Bravo-Sanchez ◽  
Elías Rodriguez-Segura ◽  
Alonso Jimenez-Garibay ◽  
...  
Keyword(s):  
Control Systems ◽  
Operating Conditions ◽  
Real System ◽  
Photovoltaic System ◽  
Hill Climbing ◽  
Integration Time ◽  
System Control ◽  
Hardware In The Loop ◽  
The Real ◽  
Point Tracking

The hardware in the loop (HIL) technique allows you to reproduce the behavior of a dynamic system or part of it in real time. This quality makes HIL a useful tool in the controller validation process and is widely used in multiple areas including photovoltaic systems (PVSs). This study presents the development of an HIL system to emulate the behavior of a PVS that includes a photovoltaic panel (PVP) and a DC-DC boost converter connected in series. The emulator was embedded into an NI-myRIO development board that operates with an integration time of 10 µs and reproduces the behavior of the real system with a mean percent error of 2.0478%, compared to simulation results. The implemented emulator is proposed as a platform for the validation of control systems. With it, the experimental stage is carried out on two controllers connected to the PVS without having the real system and allowing to emulate different operating conditions. The first controller is based on the Hill Climbing algorithm for the maximum power point tracking (MPPT), the second is a proportional integral (PI) controller for voltage control. Both controllers generate settling times of less than 3 s; the MPPT controller generates variations in the output in steady state inherent to the algorithm used. For both cases, the comparison of the experimental results with those obtained through software simulation show that the platform fulfills its usefulness when evaluating control systems.

scholarly journals Analysis of an Impact of Inertia Parameter in Active Disturbance Rejection Control Structures

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1801
Author(s):  
Dariusz Pazderski ◽  
Radosław Patelski ◽  
Bartłomiej Krysiak ◽  
Krzysztof Kozłowski
Keyword(s):  
Control Systems ◽  
Distributed Control ◽  
Disturbance Rejection ◽  
Theoretical Description ◽  
Operating Conditions ◽  
Control Structures ◽  
Main Research ◽  
Active Disturbance Rejection ◽  
Disturbance Rejection Control ◽  
Inertia Parameter

This paper is focused on a distributed control of fully actuated manipulators under operating conditions when dynamic couplings between their joints are insignificant. The main research aspect was to examine the influence of the inertia parameter on the tracking quality for control systems based on the active rejection paradigm. The theoretical description and preliminary hypothesis were supported by extensive simulation and experimental results. In particular, it is demonstrated that choosing the inertia parameter according to the real dynamics properties does not guarantee the best performance of the considered control structures.

scholarly journals Variable Geometry Fuel Injector for Low Emissions Gas Turbines

1999 ◽  
Author(s):  
K. Smith ◽  
R. Steele ◽  
J. Rogers
Keyword(s):  
Gas Turbines ◽  
Field Tests ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Variable Geometry ◽  
Fuel Injector ◽  
System Variable ◽  
Lean Premixed Combustion ◽  
Stable Operating ◽  
Lean Premixed

To extend the stable operating range of a lean premixed combustion system, variable geometry can be used to adjust the combustor air flow distribution as gas turbine operating conditions vary. This paper describes the design and preliminary testing of a lean premixed fuel injector that provides the variable geometry function. Test results from both rig and engine evaluations using natural gas are presented. The variable geometry injector has proven successful in the short-term testing conducted to date. Longer term field tests are planned to demonstrate durability.

Numerical Characterisation of Jet-Vane based Thrust Vector Control Systems

2015 ◽  
Vol 65 (4) ◽  
pp. 261 ◽  
Author(s):  
M.S.R. Chandra Murthy ◽  
Debasis Chakraborty
Keyword(s):  
Vector Control ◽  
Control Systems ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Static Tests ◽  
Thrust Vector Control ◽  
Thrust Vector

<p>Computational fluid dynamics methodology was used in characterising jet vane based thrust vector control systems of tactical missiles. Three-dimensional Reynolds Averaged Navier-Stokes equations were solved along with two-equation turbulence model for different operating conditions. Nonlinear regression analysis was applied to the detailed CFD database to evolve a mathematical model for the thrust vector control system. The developed model was validated with series of ground based 6-Component static tests. The proven methodology is applied toa new configuration.</p><p><strong>Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 261-264, DOI: http://dx.doi.org/10.14429/dsj.65.7960</strong></p>

Paper 8: The Dynamic Performance of Tractor–Implement Combinations

1969 ◽  
Vol 184 (17) ◽  
pp. 68-82
Author(s):  
M. J. Dwyer
Keyword(s):  
Control System ◽  
Control Systems ◽  
Dynamic Performance ◽  
Field Tests ◽  
Field Performance ◽  
Standard Test ◽  
Forward Speed ◽  
Response Characteristics ◽  
Sensing Systems ◽  
Significant Difference

The dynamic performance of tractor-implement combinations is considered theoretically in terms of the changes in load, weight transfer, and forward speed arising from variations in implement working depth. Two tractors, one having a top-link sensing control system and the other having a lower-link sensing control system, were modified so that the driving wheels ran eccentrically, imparting a sinusoidal variation in working depth to mounted implements and field tests were carried out using mouldboard and chisel ploughs. The draught and vertical forces between the tractors and implements were recorded continuously during the test runs, together with implement working depth, tractor engine speed, and forward speed. Measured variations in draught correlated well with the variations predicted from laboratory measurements of the tractor implement-control system characteristics. It is concluded, therefore, that field performance can be predicted from standard test data if such measurements are incorporated. The theoretical analysis is used to suggest optimum parameters for implement-control systems. With fully-mounted implements, no significant difference was found between top- and lower-link sensing systems which were otherwise similar. Chisel ploughs were shown to be more difficult to control than mouldboard ploughs. Higher sensititivies would be required to retain control at higher working speeds and also for operating semi-mounted implements with lower-link sensing systems. Semi-mounted chisel ploughs are likely to be more easily controlled than fully mounted ones, but semi-mounted mouldboard ploughs would be slightly more difficult to control than fully mounted ones. A small dead-band in the response characteristics of implement-control systems is shown to have negligible effect on performance, and current maximum rates of lift are likely to be adequate for control purposes.

Sign in / Sign up

Export Citation Format

Share Document