Proportional Control

In this paper, a new method for the calculation of all stabilizing PI controllers is given. The proposed method is based on plotting the stability boundary locus in the (kp, ki)-plane and then computing the stabilizing values of the parameters of a PI controller. The technique presented does not require sweeping over the parameters and also does not need linear programming to solve a set of inequalities. Thus it offers several important advantages over existing results obtained in this direction. Beyond stabilization, the method is used to shift all poles to a shifted half plane that guarantees a specified settling time of response. Computation of stabilizing PI controllers which achieve user specified gain and phase margins is studied. It is shown via an example that the stabilizing region in the (kp, ki)-plane is not always a convex set. The proposed method is also used to design PID controllers. The limiting values of a PID controller which stabilize a given system are obtained in the (kp, ki)-plane, (kp, kd)-plane and (ki, kd)-plane. Furthermore, the proposed method is used to compute all the parameters of a PI controller which stabilize a control system with an interval plant family. Examples are given to show the benefits of the method presented.

We study the stability of two queueing delay-based congestion control algorithms, the (p, 1)-proportionally fair algorithm and the global optimization algorithm. We linearize the systems around the intended operating point and show that these algorithms are stable within a range of feedback delay. Based on these linearized systems we study the impact of various (cascade) compensators on the system. We

— Controllers find wide applications in the field of engineering. Ordinary control system is the type of control system encountered most commonly in industrial processes and particularly in chemical processes. But it not only the one used in industries. There exists a situation where ordinary action is insufficient to produce the desired response of a given process. The type of control depends upon the type of control action used. Proportional, Derivative, integral or their combinations are generally used as control actions. Each control action has its own advantages and disadvantages. In this paper each control action has been analyzed mathematically and their merits and demerits have been compared.

Abstract Nominal characteristic trajectory following (NCTF) controller had been proposed as a practical control method of point-to-point (PTP) positioning systems. Basically the NCTF controller composes of two elements namely nominal characteristic trajectory (NCT) and a compensator. As the NCTF controller is designed based on a simple open loop response of the controlled-object, it leads to the ease of controller design and simplicity of the controller structure for practical application. Moreover, the NCTF controller also has capability to ...

... Jose Alvarez-Ramirez, Ilse Cervantes, Gerardo Espinosa-Perez, Paul Maya, and America Morales ... namely, d = 0h 01 [0 + ( 01 o 0 01 c )e]. Unfortunately, this con-trol function is not practical because the modeling error signal (t) (y(t); q(t); d(t)) is not available for feedback. ...