The prime aim of this paper is to embed a predictive control (MPC) algorithm with constraint handling capabilities into a programmable logic controller (PLC). In order to achieve it, this paper develops parametric app...
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The prime aim of this paper is to embed a predictive control (MPC) algorithm with constraint handling capabilities into a programmable logic controller (PLC). In order to achieve it, this paper develops parametric approaches to MPC but differs from more conventional approaches in that it predefines the complexity of the solution rather than the allowable suboptimality. The paper proposes a novel parameterisation of the parametric regions which allows efficiency of definition, effective spanning of the feasible region and also highly efficient search algorithms. Despite the suboptimality, the algorithm retains guaranteed stability, in the nominal case. A laboratory test was carried out to demonstrate the code on real hardware and the effectiveness of the solution. (C) 2011 Elsevier Ltd. All rights reserved.
Abstract The paper addresses the problem of numerical issues and degeneracies in the parametricquadraticprogramming (pQP) algorithm, used for computing partitions of explicit model predictive controllers (eMPC) with...
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Abstract The paper addresses the problem of numerical issues and degeneracies in the parametricquadraticprogramming (pQP) algorithm, used for computing partitions of explicit model predictive controllers (eMPC) with the multi-parametric Toolbox (MPT). We summarise the pQP problem setup and the basic algorithm, analyse its implementation in MPT, expose the numerical issues and suggest a series of improvements for more reliable operation, which are relevant also for other pQP solvers.
In order to deal with random communication time delay in Networked Control Systems(NCS), an explicit model predictive control (eMPC) method is presented in this paper. The algorithm is based on multi-parametric quadra...
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ISBN:
(纸本)9781424487363
In order to deal with random communication time delay in Networked Control Systems(NCS), an explicit model predictive control (eMPC) method is presented in this paper. The algorithm is based on multi-parametric quadratic programming to get a state feedback control law which is explicit to the states. And based on this control law, the piecewise affine model of the closed-loop model predictive control system is established. We show that the control law is piecewise linear and continuous for the finite horizon problem. Thus, the on-line control computation reduces to the simple evaluation of a piecewise affine model. Since the algorithm does not require repeated online optimization, it improves the on-line calculation speed of the controller, making the system better in real-time. The algorithm deals with the random communication time delay well. Simulation results show the effectiveness of the proposed method.
An efficient algorithm is proposed for computing the solution to the constrained finite time optimal control (CFTOC) problem for discrete-time piecewise affine (PWA) systems with a quadratic performance index. The...
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An efficient algorithm is proposed for computing the solution to the constrained finite time optimal control (CFTOC) problem for discrete-time piecewise affine (PWA) systems with a quadratic performance index. The maximal positively invariant terminal set, which is feasible and invariant with respect to a feedback control law, is computed as terminal target set and an associated Lyapunov function is chosen as terminal cost. The combination of these two components guarantees constraint satisfaction and closed-loop stability for all time. The proposed algorithm combines a dynamic programming strategy with a multi-parametric quadratic programming solver and basic polyhedral manipulation. A numerical example shows that a larger stabilizable set of states can be obtained by the proposed algorithm than precious work.
multi-parametric quadratic programming (mp-QP) is an alternative means of implementing conventional predictive control algorithms whereby one transfers much of the computational load to offline calculations. However, ...
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ISBN:
(纸本)9781424474264
multi-parametric quadratic programming (mp-QP) is an alternative means of implementing conventional predictive control algorithms whereby one transfers much of the computational load to offline calculations. However, coding and implementation of this solution may be more burdensome than simply solving the original QP. This paper shows how Laguerre functions can be used in conjunction with mp-QP to achieve a large decrease in both the online computations and data storage requirements while increasing the feasible region of the optimization problem. Extensive simulation results are given to back this claim.
Abstract This paper presents a novel control design technique in order to obtain a Guaranteed Cost Fuzzy Controller subject to constraints on the input channel. This Guaranteed cost control law is obtained via multi-p...
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Abstract This paper presents a novel control design technique in order to obtain a Guaranteed Cost Fuzzy Controller subject to constraints on the input channel. This Guaranteed cost control law is obtained via multi-parametric quadratic programming. The result is a piecewise fuzzy control law where the state partition is defined by fuzzy inequalities. The parameters of the Lyapunov function can be obtained previously using linear matrix inequalities optimization.
Solutions to constrained linear model predictive control (MPC) problems can be pre-computed off-line in an explicit form as a piecewise linear (PWL) state feedback defined on a polyhedral partition of the state space....
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Solutions to constrained linear model predictive control (MPC) problems can be pre-computed off-line in an explicit form as a piecewise linear (PWL) state feedback defined on a polyhedral partition of the state space. This admits implementation at high sampling frequencies in real-time systems with high reliability and low software complexity. Recently, algorithms that determine an approximate explicit PWL state feedback solution by imposing an orthogonal search tree structure on the partition, have been developed, and it has been shown that they may offer computational advantages. This paper considers the application of an approximate approach to the design of an explicit model predictive controller for a two-input two-output laboratory gas-liquid separation plant, including experimental evaluation. The approximate explicit MPC controller achieves performance close to that of the conventional MPC, but requires only a fraction of the real-time computational machinery, thus leading to fast and reliable computations. (C) 2004 Elsevier Ltd. All rights reserved.
This paper presents a review of the explicit approaches to constrained model predictive control. The main motivation behind the explicit solution is that it avoids the need for real-time optimization, and thus allows ...
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This paper presents a review of the explicit approaches to constrained model predictive control. The main motivation behind the explicit solution is that it avoids the need for real-time optimization, and thus allows implementation at high sampling frequencies in real-time systems with high reliability and low software complexity. The paper is organized as follows. Section I includes formulation of the constrained linear quadratic regulation (LQR) problem, summary of the implicit approaches, and the basics of the model predictive control (MPC). Sections 2 and 3 consider respectively the exact and the approximate approaches to explicit solution of constrained MPC problems, together with several examples.
This paper proposes a reference management technique of an original reference for closed-loop systems with state and control constraints. The management rule is represented in the form of a piecewise state affine func...
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ISBN:
(纸本)0780383524
This paper proposes a reference management technique of an original reference for closed-loop systems with state and control constraints. The management rule is represented in the form of a piecewise state affine function obtained from an explicit solution to a multi-parametric quadratic programming problem which explicitly considers not only a constraint fulfillment but also a tracking performance. Furthermore, effectiveness of the proposed approach is shown by simulation. It is more important to also perform the experimental evaluation to demonstrate its effectiveness using a, real position servomechanism.
In this paper, model predictive control (MPC) based optimization problems with a quadratic performance criterion and linear constraints are formulated as multi-parametricquadratic programs (mp-QP), where the input an...
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In this paper, model predictive control (MPC) based optimization problems with a quadratic performance criterion and linear constraints are formulated as multi-parametricquadratic programs (mp-QP), where the input and state variables, corresponding to a plant model, are treated as optimization variables and parameters, respectively. The solution of such problems is given by (i) a complete set of profiles of all the optimal inputs to the plant as a function of state variables, and (ii) the regions in the space of state variables where these functions remain optimal. It is shown that these profiles are linear and the corresponding regions are described by linear inequalities. An algorithm for obtaining these profiles and corresponding regions of optimality is also presented. The key feature of the proposed approach is that the on-line optimization problem is solved off-line via parametricprogramming techniques. Hence (i) no optimization solver is called on-line, and (ii) only simple function evaluations are required, to obtain the optimal inputs to the plant for the current state of the plant. (C) 2002 Elsevier Science Ltd. All rights reserved.
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