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In this paper, the potential possibilities of robust tuning of the Balance-Based Adaptive Controller (B-BAC) are discussed in terms of user-defined gain and phase margins. Considering the First Order + Dead Time (FOPDT) process to be controlled and starting from previously suggested simple B-BAC tuning method, the additional tuning parameter is introduced and its influence on the stability boundaries...
Multiple interconnected tanks supplied by more than one pump is a MIMO process which is quite common for industrial applications. Presently, Internal Model Control (IMC) technique is widely used in controlling industrial MIMO processes due to its sole tuning parameter. But, as the IMC technique is entirely based on the process model hence in case of any uncertainty in modeling, nonlinear interacting...
A flatness based decentralized Active Disturbance Rejection Control (ADRC) approach is here proposed as a means to deal with the fully nonlinear, exogenously perturbed, version, of the four-tank benchmark process problem under non-minimum phase behavior for the traditionally chosen system outputs. The liquid level control task, related to the two lower tanks, is transformed into a corresponding, indirect,...
In this paper we propose a multi-objective optimization approach for the tuning of one degree-of-freedom proportional-integral-derivative controllers where both the trade-off between the servo and regulation operation modes and the trade-off between performance and robustness are considered. After having quantified the loss of performance that occurs when robustness is taken into account in the optimal...
The paper proposes and implements a performance control structure as a answer to cascade reservoir processes. It is elaborated by relying on the combined decentralized/distributed - decoupled method specific to processes with multiple variables. In every important designing step for the structure parts, we show a few illustrative numerical examples. The intended means is set against the well-known...
The adaptive-robust control strategy, proposed in this paper, combines the advantages of robust and adaptive control, while minimizing the computational load. Usually, a lot of mathematical operations are necessary, which limit the real time applicability of such strategies. By developing a simple, yet useful rule, the number of operations needed to determine if a new controller is needed has been...
A robust fuzzy control design based on gain and phase margins specifications for nonlinear systems, with time delay, via multiobjective genetic algorithm, in the continuous time domain, is proposed. A Fuzzy C-Means (FCM) clustering algorithm estimates the antecedent parameters and the rule number of a Takagi-Sugeno fuzzy model, through from input and output data of the process, whereas the least squares...
Repetitive control (RC) is a widely used effective approach for periodic reference tracking and periodic disturbance rejection. In this paper, its use for periodic disturbance rejection and piecewise constant reference tracking is analyzed in a continuous-time framework. First, two previously proposed repetitive control structures, namely the basic repetitive controller and the current iteration repetitive...
The company NEXCIS has developed a 2-step process based on the electrodeposition (ED) of a metallic precursor subsequently annealed to produce Cu(In,Ga)(S,Se)2 absorbers (CIGS). The metallic precursor is electrodeposited on a highly conductive Mo-based back-contact on glass. It is subsequently reacted in an atmospheric pressure thermal treatment unit under chalcogens atmosphere to produce CIGS cells...
We present in this paper the analysis and the synthesis of robust iterative learning control RILC for linear continuous system based on H∞ approach. The two dimensional 2D systems are studied here to improve the monotonically convergence and to prove the efficiency of the proposed approach. Linear matrix inequality LMI techniques are also used to compute the P type RILC algorithm.
In this paper, new sliding mode control scheme is presented for control of nonlinear processes. The method is proposed for process control applications in spite of model uncertainties, nonlinear dynamics and external disturbances. Using nominal system and related bounds of uncertainties, tuning parameters are obtained from reachability condition. The effectiveness of proposed method is shown by simulations...
In this paper we designed a Fractional order controller for level control system. Based on experimental model of the process, the different tuning rules have been computed and compared in order to minimize the integral square error with a constraint on the maximum sensitivity. To assess the controller performance with achieved performance, we tested the robustness of the system for process model stability...
This paper reviews the use of linear matrix inequalities (LMIs) and bilinear matrix inequalities (BMIs) in the formulation of many important problems in process control such as: control structure selection, robust controller analysis and design, parameter estimation, and optimal design of experiments.
This paper analyzes the performance and robustness of some of the structures of dead-time compensators that have been proposed in literature. The analysis is made using the two most typical models of processes with delay that are found in the process industry. All the structures are compared to a simple two degree of freedom Smith predictor. The comparative analysis shows that for the cases studied...
An approach is presented to design a robust PI-controller from bounded noise measurement data of a first order process with and without time delay. This controller guarantees a known robust performance. It is shown that in the case without time delay, the conservatism of the robust approach can be reduced by consciously choosing the nominal plant. The theory is illustrated to a first-order process...
This paper presents the application of a Generalized Predictive Controller (gpc) to sludge density control in a sugar factory. The loop is controlled by a cascade strategy, where both the master and the slave controllers are predictive ones. The control law is extremely simple to compute and the tuning is straightforward since a method to implement GPC previously developed by the authors which is...
Actuator constraint handling is necessary for many cross-directional controllers. We discuss how optimal steady state performance can be guaranteed by modifying an internal model control structure with a non-linear element. For the simple dynamics associated with most web processes this also gives good closed-loop dynamic behaviour. Thus unconstrained control design techniques may be applied directly...
For first order plus dead time models, an optimal method for tuning PI controllers is presented using dimensional analysis and numerical optimisation techniques. Considering a step change in setpoint, optimal equations for determining PI parameters are obtained through minimising the integral of absolute error (IAE). The optimisation process is constrained to guarantee a minimum Gain margin (G.M.)...
The scale of the Software-Defined Network (SDN) Controller design problem has become apparent with the expansion of SDN deployments. Initial SDN deployments were small-scale, single controller environments for research and usecase testing. Today, enterprise deployments requiring multiple controllers are gathering momentum e.g. Google’s backbone network, Microsoft’s public cloud, and NTT’s edge gateway...
An automatic procedure for H∞ regulator tuning is proposed. Design parameters are calculated based on a few parameters of a simple plant model, which are obtained by an identification method. With this approach adequate performance and robustness are guaranteed, and it is available an automatic H∞ design method for the user. A fine-tuning of the controller can be made depending on two parameters,...
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