Category: Process Control Improvement Process Control Opportunity Assessment Process Control Benefits Tips Valve Position Control
Submitted by Greg McMillan on Fri, 06/06/2014 - 21:58
The benefits from process control improvement originate from increases in process efficiency, flexibility, and capacity. Often, there is a tradeoff where an increase in flexibility or capacity is accompanied by a decrease in efficiency. Better measurements, process knowledge, online metrics, and an enhanced PID can provide a more intelligent and...
Category: External Reset Feedback Dead Time Enhanced PID Feedforward Control Valve Position Control Tips
Submitted by Greg McMillan on Fri, 04/18/2014 - 16:59
The power of the PID largely remains underutilized. Most of the options and parameters other than scale ranges and tuning settings remain at their defaults. Here we look how to tap into the incredible capability of the PID to minimize batch cycle time and start-up time and to maximize production...
Category: Deadtime Compensator Feedforward Control PID Options Override Control Valve Position Control Tips Enhanced PID External Reset Feedback Open Loop Backup
Submitted by Greg McMillan on Fri, 04/04/2014 - 12:23
Advanced regulatory control seeks to incorporate knowledge of process dynamics, disturbances, constraints, and objectives to increase process efficiency and capacity. The PID power and flexibility enables an incredible spectrum of creative opportunities to achieve these goals.
Category: Dead Time Process Dynamics PID Tuning Process Gain Time Constant Tips Bioreactor Control Valve Position Control Variable Speed Pumps
Submitted by Greg McMillan on Fri, 12/06/2013 - 16:39
Here we use the broader definition of linearity to mean constant dynamics. A linear control loop has a constant total loop dead time, constant primary and secondary time constants, and a constant open loop gain. This perspective reviews the sources of dynamics and causes of nonlinearity.
Category: Tips Valve Valve Position Control Process Gain Process Dead Time Process Dynamics Process Time Constant Process Noise
Submitted by Greg McMillan on Fri, 07/19/2013 - 15:06
With a little help from my friends I have come up with a list of process, mechanical, and piping design mistakes that have made our job as automation engineers more challenging and in some cases impossible. We learn the most by our mistakes.
Category: Tips Valve Position Control Compressor Pressure Column Pressure Header Pressure Reactor Pressure Vessel Pressure
Submitted by Greg McMillan on Mon, 10/22/2012 - 20:05
Nearly all of the deadtime in pressure loops comes from the automation system. For gas pressure there is a process time constant or integrating process gain that becomes slower as the volume increases and the throughput decreases.
Category: PID Form PID Options PID Output Limits PID Structure Setpoint Filter Setpoint Rate Limits Valve Position Control
Submitted by Greg McMillan on Thu, 06/21/2012 - 12:46
There is an incredible offering of PID features and options enabling maximum disturbance rejection and setpoint response but also the coordination of loops and unit operation optimization. While the full aspects of the PID capability are book worthy, this checklist and an excerpt from an ISA Automation Week 2012 paper...