In this paper, a method of modeling the dynamics of electronic discussions is proposed based on the so called FOPDT model (First Order Plus Dead Time) known from the process control. Knowledge of the model points to possibility of estimating dynamic movements in discussions as well as understanding and designing their maintaining and guidance. Real discussions are processed.

This paper compares the frequency domain performance criterion (Jv) of PI, fractional PI, and PID controllers when a step load disturbance is applied at the plant input. Process information is available in form of first-order plus dead-time (FOPDT) model. In addition, the controllers were compared using the H∞–norm of the sensitivity function as a measure of robustness, and some comments on ind...

In this paper we discuss the use of a noncausal approach for the improvement of PID control, according to a method presented in (Piazzi and Visioli, 2004). In particular we verify that, despite the proposed methodology is based on an estimated first-order plus dead time (FOPDT) model of the process, different identification procedure can be employed for this purpose yielding in any case to a go...

Load-balancing problem, which covers a large area in engineering fields where several parallel entities share the same load on the systems, is studied. A control technique for solving such problem, called differences control technique (DsCT), is investigated. Two types of systems whose parallel entities can be approximated respectively as an integral and a first-order-plus-dead-time (FOPDT) mod...

This paper presents a delay-type PID controller (shortened as dPID) or a PID controller which is implemented using two delay elements. The gains are analytically tuned; one of the delay is optimally tuned and the other one is chosen to be equal to the sampling time. The poles of the discrete version of the dPID controller lies inside the unit circle and far away from the point . Hence, it is st...

In this paper, describing functions (DF) of relay with hysteresis is used for identification of systems. Describing function analysis is widely adopted in relay feedback-based identification methods because of the ease of computation involved and the general usefulness of the method. In process control systems, the noises come from measuring devices, control valves or the process itself. Dur in...

In many industrial processes, the first order plus time delay (FOPDT) is still being widely used. FOPDT systems are also called “KLT systems (gain, delay, and time constant).” Considering uncertainties in the time delay, this paper attempts to answer this research question: “Will a fractional order controller help and do better?” In this paper, we first focus on fractional order proportional an...

Most of the proportional-integral-derivative (PID) controller tuning methods reported in literature are based on the approximate plant models (FOPDT or SOPDT models) derived from the step response of the plant. In this paper, a new method of designing PID controllers using ‘impulse response’ instead of ‘step response’ of the plant is presented. Treating the impulse response of the plant as a st...

In this work, an auto-tuning procedure for PID controllers is presented. This autotuning procedure identifies a FOPDT model for a given process and uses an evolutionary algorithm to solve a constrained non-convex optimization problem to adjust the parameters of a PID controller with derivative filter. The auto-tuning procedure is validated with a set of process with different characteristics. P...