An enhanced nonlinear PID (EN-PID) controller that exhibits the improved performance than the conventional linear fixed-gain PID controller is proposed in this paper, by incorporating a sector-bounded nonlinear gain in cascade with a conventional PID control architecture. To achieve the high robustness against noise, two nonlinear tracking differentiators are used to select high-quality differe...

It is unclear to what extent the endothelium-derived hyperpolarizing factor (EDHF) contributes to the control of microcirculatory blood flow in vivo. We analyzed, by intravital microscopy in hamster muscles, the potential role of EDHF along the vascular tree under stimulated (ACh) or basal conditions. Experiments were performed in conscious as well as anesthetized (pentobarbital, urethan) anima...

It is difficult to control the movement of the robot arm due to its nonlinear structure. PID controller is still in the world because of its simplicity in designing this controller as the main controller. The nonlinear control technique is very complicated, and this is not very interesting in the controller. While fuzzy control has a better performance, it incorporates a fuzzy control with ...

We present a simple global asymptotic stability analysis, by using passivity theory for a class of nonlinear PID regulators for robot manipulators. Nonlinear control structures based on the classical PID controller, which assure global asymptotic stability of the closed-loop system, have emerged. Some works that deal with global nonlinear PID regulators based on Lyapunov theory have been report...

Industry applications mainly use linear PID algorithms might deliver an insufficient performance dealing with nonlinear operating systems. A fuzzy PID controller results in a nonlinear control surface which can be adjusted to a controlled plant by rule based modification, nonlinear membership function application and inference rule selection. The tuning process is one of the most difficult step...

Since fuzzy controllers are nonlinear, it is more difficult to set the controller gains compared to proportional-integral-derivative (PID) controllers. This research paper proposes a design procedure and a tuning procedure that carries tuning rules from the PID domain over to fuzzy single-loop controllers. The idea is to start with a tuned, conventional PID controller, replace it with an equiva...

PID controllers are designed and optimized in this paper for wood-berry distillation column using simulated annealing algorithm and particle swarm optimization method. PID controllers are the common instruments used in control applications. Construction of PID controllers is smooth and easy. It furnishes more stability and malleable while governing the processes. Thousands of PID loops strive t...

Nonlinear PID design is difficult if one approaches the problem from a global design perspective. In this paper, we propose coalescing the adaptive local linear modeling approach with traditional linear PID controller design techniques to arrive at a principled, intuitive, and simple nonlinear PID controller design methodology. The paper, in particular, discusses two local linear modeling appro...

This paper introduces a new class oj simple nonlinear PID-type controllers comprised of a sector-bounded nonlinear gain in cascade with a linear fixed-gain P, PD, PI, or PID controller. Three simple nonlinear gains are proposed: the sigmoidal function, the hyperbolic function, and the piecewise-linear function. The systems to be controlled are assumed to be modeled or approximated by second-ord...

PID controllers have been widely employed for industrial processes. Although most process systems have nonlinear properties, the effective PID parameters tuning method for nonlinear systems have not been established yet. Therefore, in this paper, a new tuning method of PID parameters is proposed for nonlinear systems using the idea of a data-based modeling method. According to the proposed meth...