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A recently proposed method for the simplification of single variable systems having ordinary polynomial denominators has been extended to the multivariable case encompassing situations where the original or simplified model may have delays in their states. The performance index used for optimization is the integral of the time-weighted squared error between the responses of the original and simplified...
In present analysis, controllers based on different tuning techniques for a pure integral process with time delay are designed for different approximation of the time delay. The controllers are compared for the approximated process for the set point tracking capability. The set point tracking capability is determined on the basis of transient as well as the steady state analysis of a step response.
On the basis of IMC framework, this paper addresses PID tuning problem for optimal IAE performance of FOPDT process with stochastic time delay. It should be noted that the traditional deterministic tuning methods can not deal with such problem since they require the exact knowledge or effective estimation of process parameters. From probabilistic point of view, the key idea of the proposed tuning...
Fractional order calculus has been used intensively to control various types of processes. The main approaches towards fractional order controllers focus on the single-input-single-output systems. The general design procedure consists in a frequency domain specification of various performance criteria followed by optimization routines. The implementation issues regarding fractional order controllers...
This document presents a new Internal Multi-Model Command controller design method for a linear system with a limited uncertain time delay. This design method is based on the use of a models collection to approximate the system functioning using Padé approximations; these models are inversed and multiplied by low pass filters in order to obtain a set of controllers to calculate the command value through...
The proposed PID tuning method has similar approach to the recently published paper of Shamsuzzoha and Skogestad (2010). It is one step procedure to obtain the PI/PID setting which gives the better performance and robustness. The method requires one closed-loop step setpoint response experiment using a proportional only controller with gain Kc0. On the bases of simulations for a range of first-order...
In this paper a novel, easy-to-use, robust design method for stable time delay processes is proposed. The purpose is obtaining a desired phase margin at a known crossover frequency. The design methodology is based on complex order integration. Complex order controllers fall into fractional order controllers category. Complex order controllers are the extended version of fractional order controllers...
This paper proposes a nonlinear controller for the stabilization of input delayed plants as well as to prove the robustness property of the reduction method. The plants considered are all of Linear Time Invariant (LTI) plants with input delay, which usually appear in process control in the industry. The core of this paper cames from the Dissipativity concept of Functional Differential Equation (FDE)...
Present work provides a discussion for synthesizing PID from IMC controller for first order delay unstable process. Recently, Lee, et al. [1] has shown the effectiveness of using MacLaurin series for synthesizing PID controller tuning relation from IMC framework. In this paper, the desired closed loop response based on optimal performance for unit set point input and input disturbance are provided...
Industrial electrical furnaces present many challenging control problems due to their non-linear dynamic behavior, uncertain and time varying parameters. This work presents internal model control approach for electrical furnaces based on nonlinear process modeling. First, a procedure for developing an approximate nonlinear analytical model of the thermal dynamic behavior of electrical furnaces in...
In this paper, a servo control strategy for tuning of fractional order PI (FO-PI) controllers is proposed for fractional order system models with and without time delays. The proposed strategy is based on a reference model, whose open-loop transfer function is given by Bode's ideal transfer function, which provides an infinite gain margin and constant phase margin. To come up with satisfactory tuning...
Nowadays IMC-PID is widely used in industrial field, but time delay problem is an unavoidable problem existing in IMC-PID design. First order Pade approximation, second order symmetric Pade approximation and second asymmetric Pade approximation are usually adopted to approximate time delay item, but these three approximation methods may bring zero-points to the system during approximation, and bring...
In this paper, model output following control based on command generator tracker is designed and applied to networked aluminum plate thermal process. One of the most important problems on networked system is the time delay problem. An explorative technique is that time delay is approximated as high order rational transfer functions. Therefore, the approximated high order system must be analyzed. Model...
A novel method is proposed to design PID controllers for stable first order and high order systems with time delay. Using a first-order Pade approximation for the transport delay, this method is based on developing a certain relationship between the coefficients of corresponding powers of s in the numerator and those in the denominator of the closed loop transfer function for FOPTD processes. Such...
In many DSP applications (image and voice processing, baseband symbol decoding in high quality communication channels) several dBs of SNR loss can be tolerated without noticeable impact on system level performance. For power optimization in such applications, voltage overscaling can be used to operate the arithmetic circuitry slower than the critical circuit path delay while incurring tolerable SNR...
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