Head suspension assembly of a commercial dual-stage HDD.

Robust Vibration Control at Critical Resonant Modes Using Indirect-Driven Self-Sensing Actuation in Mechatronic Systems

Abstract: This paper presents an improved indirect-driven self-sensing actuation circuit for robust vibration control of piezoelectrically actuated flexible structures in mechatronic systems. The circuit acts as a high-pass filter and provides better self-sensing strain signals with wider sensing bandwidth and higher signal-to-noise ratio. An adaptive non-model-based control is used to compensate for the structural vibrations […]

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Why are Automation Projects so Challenging?

Over the past five years, we have had the opportunity to review summary benchmarking data from more than 100 automation projects. This benchmarking effort, conducted by coauthor Dave Adler, includes everything from detailed cost analysis to the opinions of company management about their automation systems. This benchmarking research reveals that the top three measurement criteria […]

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February ISA Training and Education Programs Deliver New Learning Opportunities

The February ISA training and education lineup features a new exam review course for the Control Systems Technician® Level III certification as well as a Spanish-language online class to prepare for the ISA84 SIS Fundamentals Specialist credential. In addition to several online course and webinar offerings, classroom educational opportunities will be held in locations throughout […]

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Do “Smart” Instruments Need to be Calibrated?

Modern transmitters often are promoted as being smart and extremely accurate.  Sometimes you hear they don’t need to be calibrated because they are so “smart.” So why would you calibrate them? The output protocol of a transmitter does not change the fundamental need for calibration. There are numerous reasons to calibrate instruments initially and periodically. […]

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Pharmaceutical machine operating

Use Middle Signal Selection to Improve pH Measurement Reliability

Biopharmaceutical batches are often worth more than a million dollars. The product quality of these batches is sensitive to changes of 0.1 pH and the steam sterilization of electrodes reduces the life and accuracy of a sensor that under the best of conditions is the weakest link in a control system. Yet people looking at […]

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Validation of the Laguerre model.

Decomposition of an ARX Model on Laguerre Orthonormal Bases

Abstract: In this paper, we propose a new reduced complexity model by expanding a discrete-time ARX model on Laguerre orthonormal bases. To ensure an efficient complexity reduction, the coefficients associated to the input and the output of the ARX model are expanded on independent Laguerre bases, to develop a new black-box linear ARX-Laguerre model with […]

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What are the Benefits of Migrating from an Older DCS to a New Automation System?

Many distributed control systems (DCS) in process plants are approaching the end of their useful lives, forcing facilities to migrate from an old DCS to a modern automation system. Although these migration projects require significant investment, funds spent can often be recovered quite quickly through savings from improved operations, less downtime, and decreased support costs. […]

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