Otomatik ayarlanan oransal-integral-türevsel (P.I.D) kontrolörün incelenmesi ve gerçeklenmesi

Abstract

Bu çalışmada otomatik olarak ayarlanabilen oransal ( proportional )-Tümlevsel( integral )-Türevsel( derivative) (FID) kontrolörün incelenmesi ve pcl812 Simulatörü ile bası sistemlere uygulaması tanıtılmaktadır. Kendiliğinden ayarlanabilen PID kontrolörün gerçek lemesinin ilk aşamasında süreç tanıtılmaktaktadır. Bu tanıtım iki yöntemle yapılmaktadır. Birincisi birim ba samak, diğeri ise ardışıl hesaplama yöntemidir. ikinci aşamada FID kontrolörün "katsayıları Zeigler-Mchols yön temlerinden olan reaksiyon eğrisi yöntemi veya röle yön temi kullanılarak belirlenir. Belirlenen bu değerler Zeigler-Nichols'un öngördüğü katsayılara çarpılarak opti mum FID kontrolörü elde edilir ve sözkonusu süreç için uygulanır. FID kontolörün katsayılarını belirlemede kullanılan Zeigler-Nichols yöntemleri, bu katsayıları transfer fonk siyonu elde edilebilen lineer sistemler için ve %25 bağıl sönüm kriterine göre veren yöntemler olarak kısaca ifade edilebilir.

The introduction of PID controllers with auto tuning capabilities has made it possible to speed up plant commissioning and also to facilitate control optimisation through regular re tuning. However, with so many brands of autotuning PID controllers availiable on the market- that claim general applications, the end-user may be missled easily into thinking that they all similiar in performance and that they are universally applicable. It is therfore useful to provide the end-users with information on the relative capabilities and possible limitations of these autotuning PID controllers. PID controllers have several important functions-' They provide feedback, they have the ability to eliminate steady-state offsets through the integral action, they can anticipate the through the derivative action, and they can cope with actuator saturation. Much good control practise is engineered into them. PID control lers are also sufficient for many control problems particularly where are being process dynamics and modest control engineering's toolbox. A large cadre of instru ment and process are familiar with the operation of PID controllers. There is also a well-established practise of installing, tuning and using them. Although PID controllers are common and well-known they often poorly tuned. Evidence for this can be found in the control rooms of any industry. The derivative action is frequently switched off for the simple reason that is diffucult to tune properly. It is no coincidence that the derivative action can be switched off in most of the controllers that provide this function. In this study, the PID controllers, the process dy namics, the design of PID controllers and the autotuning vi subjects are discussed respectively. The FID controllers ie by far the most common control algorithm. Most feed back loops are controlled by this algorithm or minor variation of it. The PID algorithm can be approached from many different angles. It can be viewed as a device that can be operated with a few rules of thumb, but it can also be approached analytically.