Some long time delay sliding mode control approaches (original) (raw)
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Sliding mode predictive control for chemical process with time delay
Proceedings of the 16th IFAC World Congress, 2005, 2005
A design of a novel model predictive controller is presented. The proposed Sliding Mode Predictive Control (SMPC) algorithm combines the design technique of Sliding-Mode Control (SMC) with Model based Predictive Control (MPC). The SMPC showed a considerable robustness improvement with respect to MPC in the presence of time delay, and showed an enhanced ability to handle set point changes in a nonlinear process. Its robustness was evaluated using a robustness plot, its performance was judged using a single input single output nonlinear mixing tank process with variable time delay.
A New Sliding Function for Discrete Predictive Sliding Mode Control of Time Delay Systems
International Journal of Automation and Computing, 2013
The control of time delay systems is still an open area for research. This paper proposes an enhanced model predictive discrete-time sliding mode control with a new sliding function for a linear system with state delay. Firstly, a new sliding function including a present value and a past value of the state, called dynamic surface, is designed by means of linear matrix inequalities (LMIs). Then, using this dynamic function and the rolling optimization method in the predictive control strategy, a discrete predictive sliding mode controller is synthesized. This new strategy is proposed to eliminate the undesirable effect of the delay term in the closed loop system. Also, the designed control strategy is more robust, and has a chattering reduction property and a faster convergence of the system s state. Finally, a numerical example is given to illustrate the effectiveness of the proposed control.
Predictive sliding mode control for perturbed discrete delay time systems: Robustness analysis
2013 International Conference on Electrical Engineering and Software Applications, 2013
This paper presents a control strategy for perturbed discrete system with time delay, using Sliding Mode Control (SMC) and Model based Predictive Control (MPC). A predictive sliding mode control strategy is proposed and a discrete-time reaching law is improved. By applying a predictive sliding surface and a reference trajectory, combining with the state feedback correction and rolling optimization method in the predictive control strategy, a predictive sliding mode controller, for perturbed discrete system with time delay, is synthesized. The combination of SMC and MPC improves the performance of these two control laws. A robustness analysis proves that the designed control strategy has stronger robustness and chattering reduction property. Finally, a numerical example is given to illustrate the effectiveness of the proposed theory.
An approach of dynamic sliding mode control for chemical processes
Journal of Process Control, 2020
The purpose of this paper is to develop a Dynamic Sliding Mode Controller (DSMC) based on the Iinoya and Altpeter approach and the Sliding Mode Control (SMC) design procedure. The proposed approach is applied to chemical processes of high order with long dead time, and with inverse response. A simulation of a nonlinear mixing tank with variable delay, and an implementation on an Arduino Temperature Control Lab are used to test the controller. A comparison of the proposed approach (DSMC), and the SMC based on Internal Model Control (IMC) is presented to evaluate advantages and disadvantages of the proposal. The results show that the approach of the DSMC presented in this work reduces the chattering, compensates the effect of external disturbances, and of the parametric uncertainties. To measure the controller's performance, the Integral Square Error index (ISE) and Total Variation index (TV) are used.
A predictive approach based-sliding mode control
Proceedings of the 15th IFAC World Congress, 2002, 2002
This Paper shows the synthesis of Sliding Mode Controller using model predictive structure of the process. The Smith predictor architecture is combined with the Sliding mode control theory. Two different linear models, with deadtime, are simulated and the performance of the controller is evaluated.
ChemEngineering
This paper presents a dynamic sliding mode control (DSMC) for open-loop unstable chemical or biochemical processes with a time delay. The controller is based on the sliding mode and internal model control concepts. The proposed DSMC has an internal P/PD controller to provide systems with disturbance rejection. An identification method approximates the open-loop unstable nonlinear process to a first-order delayed unstable process (FODUP). The reduced-order model(FODUP) is used to synthesize the new controller. The performance of the controller is stable and satisfactory despite nonlinearities in the operating conditions due to set-point and process disturbance changes. In addition, the performance analysis of the control schemes was evaluated based on various indices and transient characteristics, including the integral of squared error (ISE), the total variation of control effort (TVu), the maximum overshoot (Mp), and the settling time (ts). Finally, the process output and the contr...
A GPC-based Sliding Mode Controller or nonlinear chemical processes
This article presents a sliding mode controller that uses a generalized predictive controller in the reaching mode. The proposed predictive sliding mode controller is developed from a first-order-plus-deadtime model that represents a good approximation to many chemical processes. The predictive sliding mode controller has six tuning parameters and the tuning rules are given in the paper. Four simulation examples show the features of the proposed controller, which overcomes some of the disadvantages of sliding mode control and generalized predictive control strategies.
Design of an explicit constrained predictive sliding mode controller
IET Control Theory & Applications, 2010
ABSTRACT This article presents a generalised predictive controller with improved performance and robustness by means of a reaching law to force a pseudosliding dynamic behaviour. This work has been motivated first by the existence of many industrial non-linear processes that can be well approximated by first-order plus dead time models. Thus, an explicit control law can be obtained, which overcomes some of the disadvantages of traditional sliding mode control and generalised predictive control strategies. Moreover, the necessity of providing the operators with useful values for a controller first tuning computed from the modelled pole and delay is also satisfied. Some simulation examples show the good characteristics of the proposed controller, coping with modelling errors, constraints on the control variable and on the manipulated variable, and time-varying delays.
On the Design of Sliding-Mode Static-Output-Feedback Controllers for Systems With State Delay
IEEE Transactions on Industrial Electronics, 2000
This paper considers the development of sliding-5 mode-based output-feedback controllers for uncertain systems 6 which are subject to time-varying state delays. A novel method 7 is proposed for design of the switching surface. This method 8 is based on the descriptor approach and leads to a solution in 9 terms of linear matrix inequalities (LMIs). When compared to 10 existing methods (even for systems without delays), the proposed 11 method is efficient and less conservative than other results, giving 12 a feasible solution when the Kimura-Davison conditions are not 13 satisfied. No additional constraints are imposed on the dimensions 14 or structure of the reduced order triple associated with design of 15 the switching surface. The magnitude of the linear gain used to 16 construct the controller is also verified as an appropriate solution 17 to the reachability problem using LMIs. A stability analysis for 18 the full-order time-delay system with discontinuous right-hand 19 side is formulated. This paper facilitates the constructive design 20 of sliding-mode static-output-feedback controllers for a rather 21 general class of time-delay systems. A numerical example from the 22 literature illustrates the efficiency of the proposed method. 23 Index Terms-Linear matrix inequalities (LMIs), sliding-mode 24 control (SMC), static output feedback (SOF), time delay. 25 I. INTRODUCTION 26 S LIDING-MODE control (SMC) [1] is known for its com-27 plete robustness to so-called matched uncertainties (which 28 can include time delays that satisfy matching conditions) and 29 disturbances [2]-[4]. The control technique has been applied in 30 many industrial areas [5]-[7]. Many early theoretical develop-31 ments in SMC assume that all the system states are accessible. 32 In the case where only a subset of states are measurable, which 33 is relevant to a range of practical applications, either output 34 feedback control or the observer-based method are required. 35 Some work has considered implementation of SMC schemes 36 using observers [8]-[10]. In [11], a sliding-mode observer has 37 been shown to give a significant increase in performance in esti-38 mation of the unknown variables of a boost converter compared
Lecture Notes in Electrical Engineering, 2016
This paper shows comparison between the Predictive Sliding Mode Controller (PSMC) and the Sliding Mode Controller with Predictive Sliding Function (SMC-PSF). The proposed controllers combine the design of Sliding Mode Control (SMC) with Model Predictive Control (MPC). This combination improves the performance of these two control laws. In fact, using a non-minimum phase system, the performances of the (PSMC) and the (SMC-PSF), in terms of strong robustness to external disturbance, parameters variation, chattering elimination and fast convergence were judged better, in comparison with SMC and MPC. Comparing the two controllers PSMC and SMC-PSF , the simulation results show that the SMC-PSF is more able to eliminate oscillations at the phase of convergence and at the presence of hard parameters variation.