scholarly journals COURSE-KEEPING CONTROL FOR DIRECTIONALLY UNSTABLE LARGE TANKERS USING THE MIRROR-MAPPING TECHNIQUE

Brodogradnja ◽  
2020 ◽  
Vol 71 (4) ◽  
pp. 67-80
Author(s):  
Bai Chunjiang ◽  
◽  
Wang Hui ◽  
Ju Tingting ◽  
Shi Hanwen

This study examines the course-keeping control of directionally unstable large oil tankers involving a pole in the right half plane. Treated as an unstable plant in control engineering, tankers are theoretically and experimentally investigated during the controller design process. First, the unstable plant is mirror-mapped to its corresponding stable minimum phase plant using the mirror-mapping technique, which enables an easy controller design. Then, a linear proportional-differential and a first-order filter controller is designed based on the closed-loop gain shaping algorithm, which requires only one controller parameter to be properly selected based on the system’s characteristics. Numerical simulation results confirmed that the designed controller can successfully stabilise an unstable plant subjected to external wind and wave disturbances. The controller designed with the proposed method is suitable for course-keeping control of directionally unstable large tankers. The controller design method is simple with an uncomplicated structure that can easily be implemented in engineering endeavours. Moreover, the rudder motion is small and soft.

2015 ◽  
Vol 798 ◽  
pp. 261-265
Author(s):  
Miao Yu ◽  
Chao Lu

Identification and control are important problems of power system based on ambient signals. In order to avoid the model error influence of the controller design, a new iterative identification and control method is proposed in this paper. This method can solve model set and controller design of closed-loop power system. First, an uncertain model of power system is established. Then, according to the stability margin of power system, stability theorem is put forward. And then controller design method and the whole algorithm procedure are given. Simulation results show the effective performance of the proposed method based on the four-machine-two-region system.


2018 ◽  
Vol 69 (2) ◽  
pp. 117-127
Author(s):  
Štefan Bucz ◽  
Alena Kozáková ◽  
Vojtech Veselý

AbstractThe paper presents a new original robust PID design method for non-minimum phase plants to achieve closed-loop performance prescribed by the process technologist in terms of settling time and maximum overshoot, respectively. The proposed design procedure has two steps: first, the uncertain system is identified using external harmonic excitation signal with frequency, second, the controller of the nominal system is designed for specified gain margin. A couple of parameters is obtained from the time domain performance specification using quadratic regression curves, the so-called performance Bparabolas so, as to simultaneously satisfy robust closed-loop stability conditions. The main benefits of the proposed method are universal applicability for systems with both fast and slow dominant dynamics as well as performance specification using time domain criteria. The proposed PID design method has been verified on a set of benchmark systems.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 437 ◽  
Author(s):  
Sangmin Suh

This note presents an optimal design method to enhance image quality in optical image stabilization (OIS) systems. First of all, performance limitations of conventional methods are shown and secondly, a new design framework based on convex optimization is proposed. The resulting controller essentially stabilizes the closed loop systems because the proposed method is derived from Lyapunov stability. From the test results, it is confirmed that this method reduces the effect of hand vibrations and makes images sharp. Additionally, it is shown that the proposed method is also effective in robot vision and recognition rate of deep neural network (DNN) based traffic signs and pedestrians detection in automotive applications. This note has three main contributions. First, performance limitations of the conventional method are shown. Second, from the relation between sensitivity and complementary sensitivity functions, an indirect design method for performance improvement is proposed, and finally, stability guaranteed optimal design is proposed. Unlike conventional methods, the proposed method does not require addition filters to suppress resonances of the plant and this note highlights phases of the closed loop systems on removing external vibrations.


1999 ◽  
Vol 122 (3) ◽  
pp. 393-401 ◽  
Author(s):  
MingQing Xiao ◽  
Tamer Bas¸ar

The paper studies the behavior of multi-mode systems of the Moore-Greitzer model. Its main result is the existence of a parameterized nonlinear state feedback controller which stabilizes the system to the right of the peak of the compressor characteristic. In this process, a rotating stall envelope surface is discovered, and it is shown that the controller design achieves the tasks of preventing the closed-loop system from entering either rotating stall or surge, and making the closed-loop pressure rise coefficient be able to approach its maximum. Numerical simulations of the open-loop and closed-loop models are presented to illustrate the analysis and the results. [S0022-0434(00)00803-0]


Author(s):  
Zhizheng Wu ◽  
Azhar Iqbal ◽  
Foued Ben Amara

In this paper, a decentralized robust PID controller design method is proposed for multi-input multi-output systems. The system model is first decoupled in the low frequency range, and only the diagonal entries in the DC-decoupled plant model are retained. To deal with the resulting unmodeled high frequency dynamics, a decentralized robust PID controller design method is proposed, where the robust stability and transient response performance of the resulting closed loop system are formulated as a multi-objective H∞/H2 static output feedback problem. The desired parameters of the PID controller are determined by solving a static output feedback problem using linear matrix inequalities (LMIs). Finally, the performance of the proposed control algorithm is experimentally evaluated on the adaptive optics system involving a prototype magnetic fluid deformable mirror (MFDM). The experimental results illustrate the effectiveness of the proposed control algorithm for the MFDM surface shape tracking in the closed loop adaptive optics system.


1998 ◽  
Vol 122 (3) ◽  
pp. 560-566 ◽  
Author(s):  
Reed D. Hanson ◽  
Tsu-Chin Tsao

This paper addresses discrete-time, repetitive control for linear, periodic, time-varying systems. A periodic, repetitive control design method based on gain scheduling is proposed and the necessary and sufficient condition for closed-loop stability is presented. Utilizing the special structure of the repetitive controller, an efficient method for evaluating the closed-loop stability is developed. The algorithm is applied to the control of a piezoelectric fast-tool stage for variable spindle speed noncircular turning process. The tool performs dynamic variable depth of cut machining to generate noncircular workpiece profiles while the spindle carrying the workpiece rotates at a variable speed to inhibit machining instability (chatter). Experimental machining results are presented that demostrate the tracking performance of the period, time-varying controller design proposed, as well as the ability to increase machining stability using this approach. [S0022-0434(00)02402-3]


1997 ◽  
Vol 119 (2) ◽  
pp. 200-207 ◽  
Author(s):  
G. J. Sheu ◽  
S. M. Yang ◽  
C. D. Yang

A new design methodology for the vibration control of rotor systems with a magnetic bearing is developed in this paper. The methodology combines the experimental design method in quality control engineering and the conventional PD control technique such that their advantages in implementation feasibility and performance-robustness can be integrated together. A quality loss index defined by the summation of the infinity norm of unbalanced vibration is used to characterize the system dynamics. By using the location of the magnetic bearing and PD feedback gains as design parameters, the controller can be determined by a small number of matrix experiments to achieve the best system performance. In addition, it is robust to the vibration modes within a desired speed range. A rotor system consisting of 4 rigid disks, 3 isotropic bearings, and 1 magnetic bearing is applied to illustrate the feasibility and effectiveness of the experiment-aided controller design.


2014 ◽  
Vol 24 (3) ◽  
pp. 333-349 ◽  
Author(s):  
Vojtech Veselý ◽  
Jakub Osuský ◽  
Ivan Sekaj

Abstract This paper presents a gain scheduled controller design for MIMO and SISO systems in the frequency domain using the genetic algorithms approach. The proposed method is derived from the M-delta structure of closed loop MIMO (SISO) systems and the small gain theory is exploited to obtain the stability condition. An example of real system illustrates the effectiveness of the proposed output feedback gain scheduled controller design method and also the possibility to improve its performance using the genetic algorithm


2013 ◽  
Vol 421 ◽  
pp. 16-22
Author(s):  
Shan Shan Wu ◽  
Wei Huo

A new stabilization control method for underactuated linear mechanical systems is presented in this paper. By proper setting the desired closed-loop system, the matching condition for controller design is reduced to one equation and an adjustable parameter (damping coefficient) is introduced to the controller. Stability of the closed-loop system is proved based on passivity. As an application example, stabilization control of 2-DOF Pendubot is studied. The system is linearized at its equilibrium point and the proposed controller design method is applied to the linearized system. The procedure of solving matching condition and design controller for the Pendubot is provided. The simulation results verify feasibility of the proposed method.


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