State estimation of distributed-parametersystem is a prerequisite of optimal control for systems of this kind. In chemical industry, a number of reactors belong to distributed-parametersystem, among which the fixed-...
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State estimation of distributed-parametersystem is a prerequisite of optimal control for systems of this kind. In chemical industry, a number of reactors belong to distributed-parametersystem, among which the fixed-bed reactor is a typical one. Nevertheless, only very much limited state variable measurements are allowed in industrial practice. In addition, time delay of the determination is commonly inevitable. The goal of state estimation for a dynamic system is focused on a quick and accurate approach to the
The variable structure control problems of distributed parameter system are in vestrigated in this *** the conditions more general than in[1],[2],the equivalent, control theorem is ***,as an application to system of ...
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The variable structure control problems of distributed parameter system are in vestrigated in this *** the conditions more general than in[1],[2],the equivalent, control theorem is ***,as an application to system of heat process,we give some conditons for sliding model such that the solution of system of heat process is exonentially stable unde the variable structure control.
A simple procedure for the design of a controller for diffusion processes is presented, based on the decoupled state space model reduced by the finite Fourier transform technique. A Kalman filter is used to estimate t...
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The relationship between two distributed parameter systems can be linked by a homeomorphic mapping, and the core is to study the minimizer of the functional to measure the degree of their similarity. We prove the exis...
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The relationship between two distributed parameter systems can be linked by a homeomorphic mapping, and the core is to study the minimizer of the functional to measure the degree of their similarity. We prove the existence and the necessary conditions (a maximum principle) for the minimizer. The similarity degree between two distributed parameter systems is thus defined by the functional, which extends the conjugacy in dynamical systems. As applications, we consider parabolic systems that satisfy different similarities. We prove a Hartman-Grobman theorem for general parabolic systems. We also demonstrate asymptotic similarity for the general quasilinear parabolic systems, indicating the Clausius statement of the second law of thermodynamics. (c) 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Many thermal processes, described by distributed parameter systems (DPSs), work in a large-scale operation region. In each region, it has special nonlinear dynamics due to specific relative position with heat sources....
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Many thermal processes, described by distributed parameter systems (DPSs), work in a large-scale operation region. In each region, it has special nonlinear dynamics due to specific relative position with heat sources. Achieving a global dynamic model of this kind of processes is extremely difficult due to different local dynamic features. Here, a spatial graphic relation-based spatiotemporal fuzzy modeling method is proposed to reconstruct the model of the large-region DPSs. First, a spectral clustering strategy is developed for region division, where the large-scale spatiotemporal region is divided into several local regions. For each local region, the spatial basis functions (SBFs) are extracted to represent the energy exchange on space. To reflect the global spatial feature, an incremental fuzzy fusion approach is designed and integrates these SBFs to form a global spatial function. Then, the temporal dynamics is obtained by projecting the spatiotemporal data on this global spatial function and characterized by a fuzzy model. Integrating the global spatial function and temporal model, the spatiotemporal model is constructed for the process with large-scale operation region. Using theoretical analysis and experiment, modeling ability of the proposed model is demonstrated effectively.
Complex distributed parameter systems (DPSs) are prevalent in numerous industrial processes. However, the nonlinear spatiotemporal dynamics inherent in DPS present significant challenges for accurate modeling. In this...
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Complex distributed parameter systems (DPSs) are prevalent in numerous industrial processes. However, the nonlinear spatiotemporal dynamics inherent in DPS present significant challenges for accurate modeling. In this paper, an innovative online three-dimensional (3D) fuzzy multi-output support vector regression learning method is proposed for DPS modeling. The proposed method employs spatial fuzzy basis functions from the 3D fuzzy model as kernel functions, enabling direct construction of a comprehensive fuzzy rule base. parameters C and epsilon in the 3D fuzzy model adaptively adjust according to data sequence variations, effectively responding to system dynamics. Furthermore, a stochastic gradient descent algorithm has been implemented for real-time updating of learning parameters and bias terms. The proposed method was validated through two typical DPS and an actual rotary hearth furnace industrial system. The experimental results show the effectiveness of the proposed modeling method.
During the operation of a distributed parameter system (DPS), its working conditions typically undergo dynamic changes. Although online learning methods can enable models to adapt to new working conditions to some ext...
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During the operation of a distributed parameter system (DPS), its working conditions typically undergo dynamic changes. Although online learning methods can enable models to adapt to new working conditions to some extent, they often confront the "catastrophic forgetting" problem, where the updated model forgets historical working conditions. On the other hand, only a few new samples can be collected during online operation, and the sparse samples make it difficult to establish accurate models for new working conditions. Therefore, achieving precise control under full working conditions remains a challenging problem. To address these challenges, this paper proposes an adaptive predictive control method based on continuous learning that achieves stable control under full working conditions by continuously identifying working conditions and triggering adaptive model updates in real time. Specifically, a spatial-temporal feature-based working condition identification method is first proposed to identify changes in working conditions automatically. Then, to address the challenge of limited data for model updating, a parameter transfer method is proposed. Simultaneously, to ensure that the updated model retains the ability to characterize historical working conditions, an Elastic Weight Consolidation (EWC) constraint is incorporated into the loss function, thus overcoming the catastrophic forgetting problem, and ensuring the updated model can represent both the historical and new working conditions. Finally, by incorporating this condition identification mechanism and adaptive predictive model into the model predictive control framework, continuous precise control of DPS can be achieved. To demonstrate the superiority of the proposed method, extensive experiments are designed. Experimental results show that the proposed method can accurately identify new working conditions and learn new condition models with only a few online samples while overcoming model mismatch of his
The present paper is devoted to sampled-data control design of a PDE-PDE cascade system. These PDEs are governed by heat equations with different reaction coefficients. In order to stabilize the cascaded heat-heat sys...
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The present paper is devoted to sampled-data control design of a PDE-PDE cascade system. These PDEs are governed by heat equations with different reaction coefficients. In order to stabilize the cascaded heat-heat system, we start with the design of continuous-time feedback control law. Then sampled-data control is further proposed for practical reasons. Sufficient conditions are derived for guaranteeing the exponential stability and well-posedness of the corresponding closed-loop system via Lyapunov method and modal decomposition method. Numerical examples illustrate the efficiency of the proposed method. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
This article mainly investigates the problem of vibration suppression and angle cooperative tracking control of a multiple flexible manipulators described by partial differential equations (PDEs) with input quantizati...
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This article mainly investigates the problem of vibration suppression and angle cooperative tracking control of a multiple flexible manipulators described by partial differential equations (PDEs) with input quantization, actuator failures, and unmodeled system dynamics. An intermediate control law is designed, and a smooth function with a positive integrable time-varying function is introduced. Besides, a new smooth function is constructed in the control law to handle the influence of quantization and actuator faults. Under the designed controller, the angles of all flexible manipulators can reach consensus through mutual communication, and the elastic deformation of each flexible manipulator can also be suppressed. Furthermore, the asymptotic stability of a closed-loop system is realized based on the Lyapunov function. Finally, numerical simulation validates the effectiveness of the method.
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