Due to simplicity and robustness, classical PID and SMC have been still widely used in practical applications. Performance of these controllers (PID and SMC) depends upon the value of some of the constant controller parameters. To avoid the most commonly used tedious trial and error method, this paper proposes an improved PSO based method for getting the optimized value of these parameters. For...

This paper proposes two novel fuzzy fractional PID structures. The tuning of the fuzzy fractional controllers is based on the prior knowledge of fractional-order control tuning rules. The digital implementation of these controllers is also investigated. The effectiveness and robustness of the proposed tuning methodology is illustrated through its application on a fractional-order plant. The sim...

This paper presents a way that fuzzy logic can be used in high level control functions. Specifically, we examine the use of fuzzy logic in supervisory control, for selecting discrete control actions, identifying the operating environment and evaluating controller performance. Proportional integral derivative (PID) controllers are widely used in excitation control of power systems, they exh ibit...

In this paper a new evolutionary computing method based on imperialist competitive algorithm (ICA) is used for tuning the parameters of a PID controller which is applied in a load frequency control system (LFC) in a multi area electric power system. If a large power imbalance is suddenly happened in a multi area power electric system, generation units and also consumer sides will be affected by...

Turbo-expanders are used in industries for cooling, liquefaction and also power generation. An important part of these turbines is the variable angle nozzle causing a nonlinear behavior that is not well recognized among the prime movers of the dispersed generators. In this paper, at first, the turbo expander system is evaluated in details and its nonlinear behavior is investigated. Then, the sy...

In the paper, using some MATLAB fuzzy logic toolbox Demos, in which the fuzzy controllers are compared with the classical PID ones, it is shown that the well tuned classical PID are significantly better than those fuzzy presented in the Demos. It is shown, that using fuzzy approach, it is very difficult to shape the input-output nonlinearity, describing the so called fuzzy block of the fuzzy co...

The main objectives of vehicle motion control on an automated highway system are stable and safe automatic longitudinal and/or lateral path following in a platoon of vehicles. Various controllers can be used to satisfy the same objectives, but they may require different variables to be sensed or different conditions to be met. Supervision can select a controller and switch to a different contro...

In this paper, Load Frequency Control (LFC) of isolated single area and two-area re-heat inter-connected thermal power system has been carried out by the classical controllers i.e. I, PI and PID; and implemented on the system at 1% step load perturbation under nominal loading conditions. The system responses have been simulated in MATLAB R2010a. Responses of deviation in frequencies, deviation ...

Magnetic levitation conveyor systems have many advantages compared with the general conveyor systems. Because of the non-contact structure, magnetic levitation systems offer frictionless, low noise, and the ability to operate in highly clean environment. In this environment, materials are sensitive to change location. When materials move to the desired position, the controller is required to be...