Valve stiction is the most common root of oscillation faults in process control systems, and it can cause severe deterioration performance system instability, ultimately impacting product quality safety. A new method for detecting valve stiction, based on dynamic slow feature analysis (DSFA) Hurst exponent, proposed this paper. The first utilizes DSFA to extract features (SFs) from preprocessed...

Stiction is one of the most common problems in the spring-diaphragm type control valves, which are widely used in the process industry. Although there have been many attempts to understand and detect stiction in control valves, none of the current methods can simultaneously detect and quantify stiction. There is thus a clear need in the process industry for a non-invasive method that can not on...

Stiction in control valve is one of the long-standing and common problems in the process industries, which accelerates equipment wear and even affects the stability of closed-loop systems. A valve stiction model is proposed to describe the dynamic feature of sticky valve. To detect and quantify valve stiction, a bootstrap Hammerstein system identification procedure is proposed. Through the iden...

Oscillation or large variability of the control loops results decreased economical advantage to process industries due to inferior quality products, larger rate of rejections, reduced average throughputs and overall increased energy requirements. Stiction is one of the root cause of oscillation. Many studies suggest that 30% of the control loops are oscillatory because of control valve problems...

A fracture mechanics model was developed, and experimentally verified, to model stress wave repair of stiction-failed microcantilevers. This model allows us to predict accurately the number of laser pulses, at a specific fluence and wavelength, required to fully repair stiction-failed microcantilevers. The proposed fracture mechanics model includes the strain energy stored in a stiction-failed ...

Stiction is a major failure in microelectromechanical system (MEMS) devices in which two contacting surfaces can remain stuck together because of the adhesive forces. Due to the difference between the surfaces roughness and the adhesive force range, the real contact areas are usually smaller than the apparent one, resulting in a scatter in the adhesive forces. Consequently, the stiction is an u...

Stiction failures in microelectromechanical systems (MEMS) occur when suspended elastic members are unexpectedly pinned to their substrates. This type of device failure develops both in fabrication and during device operation, being a dominant source of yield loss in MEMS. Stiction failures require first a collapse force that brings the elastic member contact with the substrate followed by an i...

MEMS (micro-electromechanical systems) devices often suffer from stiction induced reliability problems. Although a theoretical framework to describe stiction in MEMS is under development in the scientific community, experimental data are still scarce. We have developed a MEMS device that can be used to electronically measure sidewall surface forces in situ, i.e. on chip. To be able to use it, w...

Stiction is one of the most adverse non-linearities that can affect a control valve. It impacts both valve longevity and product quality. Currently available stiction compensation methods either reduce the amplitude of oscillation at a cost of increased frequency or require knowledge about process and valve models. In this study a novel stiction compensation scheme is developed which reduces bo...