Design of PID Controllers Integrator System with Time Delay and Double Integrating Processes

AbstractThe processes which contain at least one pole at the origin are known as integrating systems. The process output varies continuously with time at certain speed when they are disturbed from the equilibrium operating point by any environment disturbance/change in input conditions and thus they are considered as non-self-regulating. In most occasions this phenomenon is very disadvantageous and dangerous. Therefore it is always a challenging task to efficient control such kind of processes. Depending upon the number of poles present at the origin and also on the location of other poles in transfer function different types of integrating systems exist. Stable first order plus time delay systems with an integrator (FOPTDI), unstable first order plus time delay systems with an integrator (UFOPTDI), pure integrating plus time delay (PIPTD) systems and double integrating plus time delay (DIPTD) systems are the classifications of integrating systems. By using a well-controlled positioning stage the advances in micro and nano metrology are inevitable in order satisfy the need to maintain the product quality of miniaturized components. As proportional-integral-derivative (PID) controllers are very simple to tune, easy to understand and robust in control they are widely implemented in many of the chemical process industries. In industries this PID control is the most common control algorithm used and also this has been universally accepted in industrial control. In a wide range of operating conditions the popularity of PID controllers can be attributed partly to their robust performance and partly to their functional simplicity which allows engineers to operate them in a simple, straight forward manner. One of the accepted control algorithms by the process industries is the PID control. However, in order to accomplish high precision positioning performance and to build a robust controller tuning of the key parameters in a PID controller is most inevitable. Therefore, for PID controllers many tuning methods are proposed. the main factors that lead to lifetime reduction in gain loss of PID parameters are described in This paper and also the main methods used for gain tuning based on optimization approach analysis is reviewed. The advantages and disadvantages of each one are outlined and some future directions for research are analyzed.

Download Full-text

A time delay dynamical model for outbreak of 2019-nCoV and the parameter identification

Journal of Inverse and Ill-Posed Problems ◽

10.1515/jiip-2020-0010 ◽

2020 ◽

Vol 28 (2) ◽

pp. 243-250 ◽

Cited By ~ 29

Author(s):

Yu Chen ◽

Jin Cheng ◽

Yu Jiang ◽

Keji Liu

Keyword(s):

Dynamical System ◽

Time Delay ◽

Parameter Identification ◽

Typical Feature ◽

The Novel ◽

Isolation Rate ◽

High Isolation ◽

The Government ◽

System With Time Delay ◽

Official Data

AbstractIn this paper, we propose a novel dynamical system with time delay to describe the outbreak of 2019-nCoV in China. One typical feature of this epidemic is that it can spread in the latent period, which can therefore be described by time delay process in the differential equations. The accumulated numbers of classified populations are employed as variables, which is consistent with the official data and facilitates the parameter identification. The numerical methods for the prediction of the outbreak of 2019-nCoV and parameter identification are provided, and the numerical results show that the novel dynamic system can well predict the outbreak trend so far. Based on the numerical simulations, we suggest that the transmission of individuals should be greatly controlled with high isolation rate by the government.

Download Full-text

Stability and Stabilization of the Fractional-order Power System with Time Delay

IEEE Transactions on Circuits & Systems II Express Briefs ◽

10.1109/tcsii.2021.3069323 ◽

2021 ◽

pp. 1-1

Author(s):

Zhongming Yu ◽

Yue Sun ◽

Xin Dai

Keyword(s):

Time Delay ◽

Power System ◽

Fractional Order ◽

Stability And Stabilization ◽

System With Time Delay

Download Full-text

Nonlinear vibrations and time delay control of an extensible slowly rotating beam

Nonlinear Dynamics ◽

10.1007/s11071-020-06079-3 ◽

2020 ◽

Author(s):

Jerzy Warminski ◽

Lukasz Kloda ◽

Jaroslaw Latalski ◽

Andrzej Mitura ◽

Marcin Kowalczuk

Keyword(s):

Time Delay ◽

Control Strategies ◽

Vibration Reduction ◽

Least Action ◽

Active Elements ◽

Principle Of Least Action ◽

Second Mode ◽

Delay Control ◽

Speed Range ◽

System With Time Delay

AbstractNonlinear dynamics of a rotating flexible slender beam with embedded active elements is studied in the paper. Mathematical model of the structure considers possible moderate oscillations thus the motion is governed by the extended Euler–Bernoulli model that incorporates a nonlinear curvature and coupled transversal–longitudinal deformations. The Hamilton’s principle of least action is applied to derive a system of nonlinear coupled partial differential equations (PDEs) of motion. The embedded active elements are used to control or reduce beam oscillations for various dynamical conditions and rotational speed range. The control inputs generated by active elements are represented in boundary conditions as non-homogenous terms. Classical linear proportional (P) control and nonlinear cubic (C) control as well as mixed ($$P-C$$ P - C ) control strategies with time delay are analyzed for vibration reduction. Dynamics of the complete system with time delay is determined analytically solving directly the PDEs by the multiple timescale method. Natural and forced vibrations around the first and the second mode resonances demonstrating hardening and softening phenomena are studied. An impact of time delay linear and nonlinear control methods on vibration reduction for different angular speeds is presented.

Download Full-text