A new method of designing multi-loop pid controllers is presented in this paper. By using the generalized IMC-pid method for multi-loop systems, the optimization problem involved in finding the pid parameters is effic...
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A new method of designing multi-loop pid controllers is presented in this paper. By using the generalized IMC-pid method for multi-loop systems, the optimization problem involved in finding the pid parameters is efficiently simplified to find the optimum closed-loop time constant in a reduced search space. A weighted sum Mp criterion is proposed as a performance cost function to cope with both the performance and robustness of a multi-loop control system. Several illustrative examples are included to demonstrate the improved performance of the multi-loop pid controllers obtained by the proposed design method.
In order to identify those multivariable processes with integrating factors in their transfer function matrices, a simple yet robust decentralized identification method from closed-loop step tests is proposed. By the ...
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In order to identify those multivariable processes with integrating factors in their transfer function matrices, a simple yet robust decentralized identification method from closed-loop step tests is proposed. By the frequency response matrix computed from the closed-loop system data and the knowledge of the decentralized controller, the structural information of the multivariable integrating process is determined firstly and then the continuous parametric model with dead times is approximated similarly with the parameterization of the open-loop stable process. Computer simulations and an application to a 3 x 3 integrating multiple-tank water level system verify the validation of the proposed method even if the closed-loop system is affected by some stochastic noise sources. (c) 2007, ISA. Published by Elsevier Ltd. All rights reserved.
The cooperative control of both electrode remelting rate and position was applied in order to obtain optimal electro-slag remelting metallurgy effect and improve melting production efficiency. The nonlinear dynamic mo...
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ISBN:
(纸本)9781424417186
The cooperative control of both electrode remelting rate and position was applied in order to obtain optimal electro-slag remelting metallurgy effect and improve melting production efficiency. The nonlinear dynamic model of electro-slag remelting process was linearized. And the tineariztion model was analyzed including its stability, coupling property and variable matching strategy. The multi-loop pid controllers with cascade pidcontrollers were applied to the linearization model based on matching strategy. The dynamic performance was analyzed to electro-slag remelting control system. Study results show that linearizition model of electro-slag remelting process have characteristic of stability and weakly-coupled property. multi-looppid control system can realize stable control both electrode melting rate and electrode position. The control system has faster dynamic response and better anti-interference capability.
The Municipal solid wastes incineration (MSWI) process with complex mechanism and strong nonlinearity is an important part of resource cycle. It is a challenge to design its multivariable controlled object model and c...
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The Municipal solid wastes incineration (MSWI) process with complex mechanism and strong nonlinearity is an important part of resource cycle. It is a challenge to design its multivariable controlled object model and control strategy. To solve this problem, a multi-input multi-output (MIMO) data-driven model and a multi-loop pid controller are proposed in this paper. Firstly, a feature selection method based on Pearson correlation coefficient (PCC) and expert knowledge is used to analyze the relationship between the manipulated variable and the controlled variable of MSWI process. Secondly, a MIMO Takagi-Sugeno fuzzy neural network (TSFNN) based on multi-task learning (MTL) is designed to construct the multivariable controlled object model. Thirdly, a multi-loop pid controller based on quasi-diagonal recurrent neural network (QDRNN) is constructed, which has self-feedback channel and interconnection channel, and can adjust the control parameters automatically. Next, the stability of control strategy is proved by Lyapunov second method. Finally, the modeling effect and control performance are confirmed on the simulation experiments based on the real MSWI process data.
Despite the wide popularity of SISO tuning methods, the number of manual tuning methods for MIMO systems is limited. The MIMO control loops are usually tuned sequentially using scalar techniques. Often this is not eff...
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Despite the wide popularity of SISO tuning methods, the number of manual tuning methods for MIMO systems is limited. The MIMO control loops are usually tuned sequentially using scalar techniques. Often this is not effective since tuning one loop may detune other loops in the system. Sequential tuning methods are partially open loop, and this is not easily accepted by the plant operators. The objective of this paper is to review and compare the robustness of MIMO pid tuning methods. The study is based on a widely used model of a distillation column and simulation results are presented to demonstrate the performance of the tuning methods.
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