The application of a new PID autotuning method for the steam/water loop in large scale ships

In large scale ships, the most used controllers for the steam/water loop are still the proportional-integral-derivative (PID) controllers. However, the tuning rules for the PID parameters are based on empirical knowledge and the performance for the loops is not satisfying. In order to improve the control performance of the steam/water loop, the application of a recently developed PID autotuning method is studied. Firstly, a 'forbidden region' on the Nyquist plane can be obtained based on user-defined performance requirements such as robustness or gain margin and phase margin. Secondly, the dynamic of the system can be obtained with a sine test around the operation point. Finally, the PID controller's parameters can be obtained by locating the frequency response of the controlled system at the edge of the 'forbidden region'. To verify the effectiveness of the new PID autotuning method, comparisons are presented with other PID autotuning methods, as well as the model predictive control. The results show the superiority of the new PID autotuning method

Disturbance Observer-based Robust Control and Its Applications: 35th Anniversary Overview

Disturbance Observer has been one of the most widely used robust control tools since it was proposed in 1983. This paper introduces the origins of Disturbance Observer and presents a survey of the major results on Disturbance Observer-based robust control in the last thirty-five years. Furthermore, it explains the analysis and synthesis techniques of Disturbance Observer-based robust control for linear and nonlinear systems by using a unified framework. In the last section, this paper presents concluding remarks on Disturbance Observer-based robust control and its engineering applications.Comment: 12 pages, 4 figure

Sliding mode control of a three-DOF robotic system driven by DC motors

U ovom radu, predloženo je upravljanje u kliznom režimu kretanjem robotskog sistema sa 3 stepena slobode pogonjen jednosmernim motorima. Prvenstveno je projektovan kontroler u kliznom režimu i koji je baziran na PD kliznoj površi. Numeričke simulacije su sprovedene sa ciljem ilustrovanja osobina robusnosti predloženog sistema upravljanja kao i značaja smanjenja izlaznih oscilacija chattering-free datog robotskog sistema. Konačno, simulacioni primer pokazuje izvodljivost i efikasnost predloženog pristupa.This paper proposes a sliding mode control of a 3-DOF robotic system driven by DC motors. Primarily, a conventional sliding mode controller based on a pd sliding surface is designed. Numerical simulations have been carried out to show the proposed control system's robustness properties as well as the significance of the proposed control which resulted in reducing output oscillations (chattering-free) of the given robot. Finally, a simulation example shows the feasibility and effectiveness of the proposed approach

Sliding mode control of a three-DOF robotic system driven by DC motors

U ovom radu, predloženo je upravljanje u kliznom režimu kretanjem robotskog sistema sa 3 stepena slobode pogonjen jednosmernim motorima. Prvenstveno je projektovan kontroler u kliznom režimu i koji je baziran na PD kliznoj površi. Numeričke simulacije su sprovedene sa ciljem ilustrovanja osobina robusnosti predloženog sistema upravljanja kao i značaja smanjenja izlaznih oscilacija chattering-free datog robotskog sistema. Konačno, simulacioni primer pokazuje izvodljivost i efikasnost predloženog pristupa.This paper proposes a sliding mode control of a 3-DOF robotic system driven by DC motors. Primarily, a conventional sliding mode controller based on a pd sliding surface is designed. Numerical simulations have been carried out to show the proposed control system's robustness properties as well as the significance of the proposed control which resulted in reducing output oscillations (chattering-free) of the given robot. Finally, a simulation example shows the feasibility and effectiveness of the proposed approach

Robust fractional-order fast terminal sliding mode control with fixed-time reaching law for high-performance nanopositioning

Open Access via the Wiley Agreement ACKNOWLEDGEMENTS This work is supported by the China Scholarship Council under Grant No. 201908410107 and by the National Natural Science Foundation of China under Grant No. 51505133. The authors also thank the anonymous reviewers for their insightful and constructive comments.Peer reviewedPublisher PD

Fuzzy control turns 50: 10 years later

In 2015, we celebrate the 50th anniversary of Fuzzy Sets, ten years after the main milestones regarding its applications in fuzzy control in their 40th birthday were reviewed in FSS, see [1]. Ten years is at the same time a long period and short time thinking to the inner dynamics of research. This paper, presented for these 50 years of Fuzzy Sets is taking into account both thoughts. A first part presents a quick recap of the history of fuzzy control: from model-free design, based on human reasoning to quasi-LPV (Linear Parameter Varying) model-based control design via some milestones, and key applications. The second part shows where we arrived and what the improvements are since the milestone of the first 40 years. A last part is devoted to discussion and possible future research topics.Guerra, T.; Sala, A.; Tanaka, K. (2015). Fuzzy control turns 50: 10 years later. Fuzzy Sets and Systems. 281:162-182. doi:10.1016/j.fss.2015.05.005S16218228

Design of a model reference adaptive PID control algorithm for a tank system

This paper describes the design of an adaptive controller based on model reference adaptive PID control (MRAPIDC) to stabilize a two-tank process when large variations of parameters and external disturbances affect the closed-loop system. To achieve that, an innovative structure of the adaptive PID controller is defined, an additional PI is designed to make sure that the reference model produces stable output signals and three adaptive gains are included to guarantee stability and robustness of the closed-loop system. Then, the performance of the model reference adaptive PID controller on the behaviour of the closed-loop system is compared to a PI controller designed on MATLAB when both closed-loop systems are under various conditions. The results demonstrate that the MRAPIDC performs significantly better than the conventional PI controller