Many chemical processes have multi-timescale dynamics. This paper proposes a data-based control approach for these processes based on the behavioral systems theory. A data re-sampling method and an innovative multi-op...
详细信息
ISBN:
(数字)9781665471749
ISBN:
(纸本)9781665471749
Many chemical processes have multi-timescale dynamics. This paper proposes a data-based control approach for these processes based on the behavioral systems theory. A data re-sampling method and an innovative multi-optimization horizon data predictive control design are developed to deal with different timescales. The optimization horizons with small to large time intervals are used to predict and optimize future steps from near to distant future and deal with the dynamics of different timescales. The time intervals in different optimization horizons are aligned and the control action based on the dynamics of different timescales are optimized simultaneously. An illustrative example is included to demonstrate the proposed approach.
This article proposes a data-based Adaptive Predictive control (DBAPC) scheme for a set of unknown nonlinear dynamical systems featuring Input and Output (I/O) saturations. In the beginning, a new dynamic model is pro...
详细信息
ISBN:
(纸本)9781665454520
This article proposes a data-based Adaptive Predictive control (DBAPC) scheme for a set of unknown nonlinear dynamical systems featuring Input and Output (I/O) saturations. In the beginning, a new dynamic model is provided for a discrete-time unknown nonlinear system by considering I/O saturated data. Furthermore, according to the developed model, a predictive control method is designed for stabilizing the system. Hence, Input and Output saturations are common physical constraints in industrial procedures;the stability analysis and proving the boundedness of the tracking error are provided in the presence of the limitations mentioned above. Proving the stability of the proposed controller in the presence of I/O saturations makes it more applicable than conventional methods of model free adaptive based predictive control. Simulation studies on the Load Frequency control (LFC) problem of an interconnected three-area power system and one numerical example reveal the advantage and applicability of the proposed controller.
In this paper, we present a data-driven distributed model predictive control (MPC) scheme to stabilise the origin of dynamically coupled discrete-time linear systems subject to decoupled input constraints. The local o...
详细信息
In this paper, we present a data-driven distributed model predictive control (MPC) scheme to stabilise the origin of dynamically coupled discrete-time linear systems subject to decoupled input constraints. The local optimisation problems solved by the subsystems rely on a distributed adaptation of the Fundamental Lemma by Willems et al., allowing to parametrise system trajectories using only measured input-output data without explicit model knowledge. For the local predictions, the subsystems rely on communicated assumed trajectories of neighbours. Each subsystem guarantees a small deviation from these trajectories via a consistency constraint. We provide a theoretical analysis of the resulting non-iterative distributed MPC scheme, including proofs of recursive feasibility and (practical) stability. Finally, the approach is successfully applied to a numerical example. Copyright (C) 2022 The Authors.
This paper introduces a sequential design method for multi-loop PID controllers under the Virtual Reference Feedback Tuning (VRFT) methodology. Simulation studies are presented to illustrate the effect of different re...
详细信息
This paper introduces a sequential design method for multi-loop PID controllers under the Virtual Reference Feedback Tuning (VRFT) methodology. Simulation studies are presented to illustrate the effect of different reference models on the proposed design for two-input two-output (TITO) systems. Lastly, the proposed design is compared with benchmark designs for well-known multivariable processes. Copyright (c) 2022 The Authors. This is an open access article under the CC BY-NC-ND license (https://creativecommonsmrg/licenses/by-nc-nd 4,0)
The Koopman operator allows for handling nonlinear systems through a globally linear representation. In general, the operator is infinite-dimensional - necessitating finite approximations - for which there is no overa...
详细信息
The Koopman operator allows for handling nonlinear systems through a globally linear representation. In general, the operator is infinite-dimensional - necessitating finite approximations - for which there is no overarching framework. Although there are principled ways of learning such finite approximations, they are in many instances overlooked in favor of, often ill-posed and unstructured methods. Also, Koopman operator theory has long-standing connections to known system-theoretic and dynamical system notions that are not universally recognized. Given the former and latter realities, this work aims to bridge the gap between various concepts regarding both theory and tractable realizations. Firstly, we review data-driven representations (both unstructured and structured) for Koopman operator dynamical models, categorizing various existing methodologies and highlighting their differences. Furthermore, we provide concise insight into the paradigm's relation to system-theoretic notions and analyze the prospect of using the paradigm for modeling control systems. Additionally, we outline the current challenges and comment on future perspectives.
This paper presents a Three-Degree-of-Freedom Model Predictive control (3DoF MPC) framework based on Multi-Input-Multi-Output (MIMO) “Model-on-Demand” (MoD) estimation. MoD is a data-centric weighted regression algo...
详细信息
This paper presents a Three-Degree-of-Freedom Model Predictive control (3DoF MPC) framework based on Multi-Input-Multi-Output (MIMO) “Model-on-Demand” (MoD) estimation. MoD is a data-centric weighted regression algorithm that generates local models over adaptively varying neighborhoods of changing operating conditions. The 3DoF formulation enables individualized tuning of parameters relating to setpoint tracking and measured and unmeasured disturbance rejection. Online estimation of system dynamics using MIMO MoD and augmentation with the 3DoF MPC structure allows the generation of control laws based on efficient locally linear approximations of system nonlinearities. This paper evaluates the framework through a case study involving a nonlinear MIMO Continuous Stirred Tank Reactor (CSTR) model. The MIMO CSTR system is highly interactive, making data-driven estimation and control notably more challenging than its SISO counterpart. The generation of an informative database using modified “zippered” multisines is presented. The paper concludes with a case study demonstrating the effectiveness of 3DoF MoD MPC in achieving constrained MIMO control of reactor concentration and temperature in the presence of disturbances through a flexible and intuitive approach.
We consider the safe control problem of designing a robustly invariant set using only a finite set of data collected from an unknown input-affine polynomial system in continuous time. We consider input/state/state der...
详细信息
We consider the safe control problem of designing a robustly invariant set using only a finite set of data collected from an unknown input-affine polynomial system in continuous time. We consider input/state/state derivative data that are noisy, i.e., are corrupted by an unknown -but -bounded disturbance. We derive a data -dependent sum -of -squares program that enforces robust invariance of a set and also optimizes the size of that set while keeping it within a set of user -defined safety constraints;the solution of this program, obtained by alternation of the decision variables, directly provides a polynomial robustly invariant set and a state -feedback controller. We numerically test the design on a system of two platooning vehicles.
A data-based predictive controller is proposed, offering both robust stability guarantees and online learning capabilities. To merge these two properties in a single controller, a double-prediction approach is taken. ...
详细信息
A data-based predictive controller is proposed, offering both robust stability guarantees and online learning capabilities. To merge these two properties in a single controller, a double-prediction approach is taken. On the one hand, a safe prediction is computed using Lipschitz interpolation on the basis of an offline identification dataset, which guarantees safety of the controlled system. On the other hand, the controller also benefits from the use of a second online learning-based prediction as measurements incrementally become available over time. Sufficient conditions for robust stability and constraint satisfaction are given. Illustrations of the approach are provided in a simulated case study.
Scalability is crucial for reconfigurable manufacturing systems (RMS), allowing throughput capacity adjustments based on market demand shifts. This research applies control theory to assess scalability’s impact on RM...
详细信息
Scalability is crucial for reconfigurable manufacturing systems (RMS), allowing throughput capacity adjustments based on market demand shifts. This research applies control theory to assess scalability’s impact on RMS, understanding dynamic responses to production demand variations. Strategies are explored to efficiently manage changes, maximizing manufacturing process effectiveness. Using a discrete transfer function, the study employs virtual reference feedback tuning (VRFT) with a proportional-integral-derivative (PID) control strategy. This sophisticated, data-driven approach analyzes system responses, identifying opportunities for optimization. Integrating VRFT-PID offers a nuanced perspective, enhancing understanding of RMS behavior and refining control strategies to optimize throughput capacity in response to market dynamics.
A novel big data-predictive control approach for nonlinear multi-timescale processes is presented in this paper. Multiple Dynamical Latent Variable Autoencoders (DLVAEs) are employed to approximate multi-timescale dyn...
详细信息
A novel big data-predictive control approach for nonlinear multi-timescale processes is presented in this paper. Multiple Dynamical Latent Variable Autoencoders (DLVAEs) are employed to approximate multi-timescale dynamics, utilizing timescale-based low-pass filtering and resampling of historical input-output data. The encoder in each DLVAE projects the nonlinear physical variable space onto a linear latent variable space, represented by a kernel space in behavioral system theory. During training, we not only impose kernel spaces and reconstruct data but also establish connections among latent variables from different DLVAEs at matching time-steps. Collectively, these multi-level latent variables span a wide prediction time horizon with limited (non-uniformly spaced) steps encompassing the current, near, and distant future. In online tracking control, we guide the latent variables from each DLVAE to their respective setpoints (derived from physical variable setpoints) while maintaining consistent physical variable values at matching time-steps, all within a linear framework.
暂无评论