This work extends the current results of SISO (single-input-single-output) case H-infinity PID Controller synthesis in finite frequency domain to the subject of multivariable decentralized control. Sufficient conditions for the existence of such a decentralized PID controller are derived in terms of linear matrix inequalities (LMIs). A numerical example is given that establishes the efficacy of...

Control of a magnetic bearing device is addressed by parameter varying control. Within the structure of decentralized PID controllers we compare linear interpolation and switching strategies with and without hysteresis. Piecewise LPV decentralized PID controllers are found to be an interesting alternative. Our method exploits the possibility to pre-compute for every parameter value an H∞ optima...

In this paper, we propose a PID control design method for decentralized control systems from the inverse linear quadratic problem viewpoint by using the structure of controllers obtained by the ILQ(Inverse Linear Quadratic) design method. First, we show an optimal decentralized PID design method for systems with relative degree no more than 2 and block diagonal decoupling matrix. Then, we deriv...

A class of stabilizing decentralized proportional integral derivative (PID) controllers for an n-link robot manipulator system is proposed. The range of decentralized PID controller parameters for an n-link robot manipulator is obtained using Kharitonov theorem and stability boundary equations. Basically, the proposed design technique is based on the gain-phase margin tester and Kharitonov’s th...

The interactions between input/output in multivariable processes represent a major challenge in the design of decentralized controllers. In this paper, a simple method for the design of decentralized PID controller is proposed. It consists to combine the conventional PID controller with the static decoupler approach. For each single loop, the individual controller is independently designed by a...

The decentralized PID control design of multivariable processes is an appealing approach due to its practical applicability and the existence of a good theoretical basis. However, although industrial processes may be modeled using simple first order and second order models, in decentralized control, the models increase their complexity due to loop interaction, compromising the applicability of ...

PID control is well known and widely applied in industry and many design algorithms are readily available in the literature. However, systematic design of multi-loop or decentralized PID control for multivariable processes to meet certain objectives simultaneously is still a challenging task. Designing multi-loop PID controllers such that the process variables satisfy the generalized covariance...

Multivariable liquid level control is essential in process industries to ensure quality of the product and safety of the equipment. However, the significant problems of the control system include excessive time consumption and percentage overshoot, which result from ineffective performance of the tuning methods of the PID controllers used for the system. In this paper, fuzzy logic was used to t...