Stiction is the most common problem in pneumatic control valves, which are widely used in the process industry. Stiction causes fluctuation of process variables, which lowers productivity. Therefore, developing a method to detect stiction and distinguish it from other causes is crucial to help operators take an appropriate action for improving control performance. The present work proposes a va...

In this paper, a novel detection and quantification method of control valve stiction is discussed. A time delay estimation method is presented for processes under an oscillating state. A suitable model structure of valve stiction is chosen prior to conducting valve stiction detection and quantification. Given the stiction model structure, a bounded search space of a stiction model is defined an...

In this paper, a procedure for quantifying valve stiction in control loops based on ant colony optimization has been proposed. Pneumatic control valves are widely used in the process industry. The control valve contains non-linearities such as stiction, backlash, and deadband that in turn cause oscillations in the process output. Stiction is one of the long-standing problems and it is the most ...

The presence of nonlinearities, e.g., stiction, and deadband in a control valve limits the control loop performance. Stiction is the most commonly found valve problem in the process industry. In spite of many attempts to understand and model the stiction phenomena, there is a lack of a proper model, which can be understood and related directly to the practical situation as observed in real valv...

Nearly 20-30% of all process control loops oscillate due to stiction and lead to loss of productivity. Thus, the detection and quantification of stiction in control valves using just the raw operating data is an important component of any automated controller performance monitoring application. Many techniques have been proposed for the detection and quantification of stiction. Pattern based id...

AbstractIn this paper, a new compensator is designed so as to eliminate the effect of stiction in the control loop. A wellknown stiction compensation method is proposed that reduces variability both at process variable and valve stem movement. Pneumatic control valves are widely used in the process industry. Stiction is the most common and one of the long-standing problems in the pneumatic cont...

Valve stiction is one of the largest stand-alone reasons for oscillatory behavior in process industry. It is reported by Siemens Oil and Gas that valve stiction is a problem that is hard and time consuming to detect at offshore production plants for oil and gas. As a result, Siemens Oil and Gas wants to develop an algorithm that detects stiction. The algorithm is thought to be a feature of the ...

Oscillations in control loops lead to poor controller performance. Stiction in control valves is one of the major causes of such oscillations. Therefore, the correct diagnosis of stiction is important. There are several methods for detecting stiction, but quantification of stiction still remains a challenge. Two parameters are used to model the stiction phenomenon successfully, namely, deadband...

Stiction is one of the most common problems in the spring-diaphragm type control valves, which are widely used in the process industry. In this paper, a procedure for single curve piecewise fitting stiction detection method and quantifying valve stiction in control loops based on ant colony optimization has been proposed. The single curve piecewise fitting method of detecting valve stiction is ...

The presliding displacement and stiction properties of friction models are investigated. It is found that existing single-state-variable friction models possess either stiction or presliding displacement. Next, those models with continuous states are interpreted as examples of Prandlt’s elasto-plastic material model. A class of general one-state models is derived that is stable, dissipative and...