Automation industry articles from ISA
Presidential Executive Order on Critical Infrastructure Cybersecurity draws comprehensive response from ISA and AF U.S. Presidential Executive Order 13636, announced in President Obama’s 2013 State of the Union address and signed on 12 February, is intended to confront the growing threats and risks of destructive and potentially deadly cyber attacks on the nation’s critical infrastructure. [...]
The commissioning and configuration of digital communications of a field-level network, such as Foundation Fieldbus, is fundamental to obtaining certification of the digital communication of the segments and, hence, approval to start up the plant. Despite the fact that the Fieldbus Foundation (FF) project may have been developed and designed following all concerns, standards, such [...]
Abstract: This paper presents a simple but effective method for finding a robust output feedback controller via a random search algorithm. The convergence of this algorithm can be guaranteed. Moreover, the probability to find a solution as well as the number of random trials can be estimated. The robustness of the closed-loop system is improved [...]
Abstract: This paper reports the development of an artificial neural network based virtual linearizer for correcting nonlinearity associated with transducers connected to the data-acquisition system of a computer-based measurement system. In analog processing techniques, nonlinearity is considered to be a very serious problem that at one time was solved frequently by the piecewise linear segment [...]
As a result of the ISA Mentor Program, I have had the personal pleasure of seeing firsthand the enthusiasm and talent of new automation engineers. These engineers have incredible positive energy and computer skills. However, the challenges facing a person entering this profession are considerable. I had company training programs, technical presentations, in-house standards and [...]
Abstract: This paper describes the use of pseudo-partial derivative (PPD) to dynamically linearize a nonlinear system, and aggregation is applied to the predicted PPD, resulting in a model-free adaptive predictive control algorithm for a nonlinear system. The algorithm design is only based on the PPD derived online from the input/output data of the controlled process, [...]
Abstract: In this paper, a modified Smith predictor control scheme is proposed for periodic disturbance rejection in both stable and unstable processes with time delay. Without affecting the superior setpoint response of Smith predictor control, the regulation performance under periodic disturbance can be enhanced significantly by the proposed design. Meanwhile, the asymptotical rejection for non-periodic [...]
Few measurements are as common and widespread in terms of application, operation, and variety as is level. This measurement is defined as the determination of the position of an existing interface between two media. These media are usually fluids, but they may be solids or a combination of a solid and a fluid. The interface [...]
The distillation process uses enormous amounts of energy, consuming up to 50 percent of a refinery’s operating costs due to intense heating and cooling cycles. Proper distillation tower operation can reduce energy consumption, but plant personnel need the right information in order to improve operation. Specifically, operators must have precise measurement and control of numerous [...]
Abstract: In industrial practice, controller designs are performed based on an approximate model of the actual process. It is essential to design a control system which will exhibit a robust performance because the physical systems can vary with operating conditions and time. Gain and phase margins are well known parameters for evaluating the robustness of [...]
