PID, APC
Shown are outdoor tanks and piping for Angel's Envy Distillery, Louisville, Ky. Courtesy: Mark T. Hoske, CFE Media, Control Engineering
PID, APC April 15, 2019

Top 5 Control Engineering articles April 8-14

Articles about evaluating a system integrator, the Engineers' Choice Awards, IIoT and machine control, questions to ask an SI, and rate-predictive control were Control Engineering’s five most clicked articles from April 8-14. Miss something? You can catch up here.

By Chris Vavra
Figure 3: Running forward. Running forward down a straightaway is easy. With a view of the track ahead, the runner can compensate almost instantaneously to any slow drift to the left or right, even when sprinting at top speed. In much the same way, a feedforward controller applied to a process with limited, measurable disturbances can keep the process variable close to the setpoint easily enough. Running forward around a curve is not all that much more difficult. The runner can visually measure any impending disturbances (curves), anticipate the effect on future trajectory, and make course corrections as needed rather than afterwards. Advance knowledge allows a front-facing runner to round a curve much faster and with much less error than a rear-facing runner can. Advance knowledge allows a feedforward controller to be more aggressive and more accurate. If the controller can correctly predict how a disturbance is going to affect the process variable and how to compensate for it, the controller can afford to apply more assertive control efforts. Doing so can reduce the effects of an impending disturbance just as a runner can stay right in the center of the lane when anticipating upcoming curves. Courtesy: Control Engineering
PID, APC April 8, 2019

Top 5 Control Engineering articles April 1-7

Articles about feedforward control, rate-predictive control, IIoT and machine control, Big Data analysis, and the top stories of March 2019 were Control Engineering’s five most clicked articles from April 1-7. Miss something? You can catch up here.

By Chris Vavra
Figure 4: Control objects mirror plant objects. The analog input block on the lower left side shows object oriented industrial programming (OOIP) encapsulation. Courtesy: ControlSphere LLC
PID, APC April 5, 2019

Leverage object-oriented industrial programming

Plants and equipment are assembled from objects, so controls architecture should be too. New tools help industrial programmers deliver the productivity of object-oriented programming (OOP) without the complexity.

By Gary L. Pratt, P.E.
Figure 3: Running forward. Running forward down a straightaway is easy. With a view of the track ahead, the runner can compensate almost instantaneously to any slow drift to the left or right, even when sprinting at top speed. In much the same way, a feedforward controller applied to a process with limited, measurable disturbances can keep the process variable close to the setpoint easily enough. Running forward around a curve is not all that much more difficult. The runner can visually measure any impending disturbances (curves), anticipate the effect on future trajectory, and make course corrections as needed rather than afterwards. Advance knowledge allows a front-facing runner to round a curve much faster and with much less error than a rear-facing runner can. Advance knowledge allows a feedforward controller to be more aggressive and more accurate. If the controller can correctly predict how a disturbance is going to affect the process variable and how to compensate for it, the controller can afford to apply more assertive control efforts. Doing so can reduce the effects of an impending disturbance just as a runner can stay right in the center of the lane when anticipating upcoming curves. Courtesy: Control Engineering
PID, APC April 1, 2019

Understanding feedforward control

Feedforward controls applied to a process, with limited, measurable disturbances, can keep the process variable close to the setpoint.

By Control Engineering
Figure 1: An explosion of new architectures for data collection, storage, and analysis is modifying the Purdue Model. Courtesy: Seeq
PID, APC April 1, 2019

Top 5 Control Engineering articles March 25-31

Articles about Big Data analysis, edge computing best practices, the Engineers' Choice Awards, industrial mobile robot standards, and rate-predictive control were Control Engineering’s five most clicked articles from March 25-31. Miss something? You can catch up here.

By Chris Vavra
Figure 2: The flex fatigue rig meets the oil and gas industry’s need to test umbilical and bend strain reliever design for equipment intended for deployment further offshore and in more dynamic sea states. Courtesy: Oceaneering
PID, APC April 1, 2019

Large-scale flex fatigue test rig developed

Response to more challenging environments.

By Joao Melo and Richard Norton
Figure: Rate-predictive control (RPC) uses a pre-set move rate, and tapers the move based on the PV’s predicted (apparent or already manifest) value. The U.S. Patent and Trademark Office (USPTO) has hundreds of patents for process control; as of this writing, RPC is the only one with the claim of being inherently adaptive. Courtesy: APC Performance LLC
PID, APC March 26, 2019

What is rate-predictive control?

Advanced control: A new non-PID control algorithm, rate-predictive control (RPC), is adaptive to changes in process gain, which is helpful given the industry’s difficult history of loop tuning, auto-tuning, and model maintenance. RPC also can serve as a model-less feedback multivariable control algorithm.

By Allan Kern
Clearly defining what colors indicate in your control system is an important—and occasionally overlooked—parameter in system design. Courtesy: CFE Media file image
PID, APC March 4, 2019

Top 5 Control Engineering articles February 25 to March 3

Articles about the Engineers' Choice Awards, control systems with style, selecting a VFD scope, the future of the IIoT in manufacturing, and robotics as a service were Control Engineering’s five most clicked articles from February 25 to March 3. Miss something? You can catch up here.

By Chris Vavra
Robots powered by artificial intelligence and machine learning are being employed to carry out mundane, repetitive tasks and more complex functions such as improving quality, throughput, enhancing employee safety, reducing waste and increasing customer satisfaction. Courtesy: L&T Technology Services
PID, APC February 12, 2019

Robotics and AI improve factories of the future

Cover Story: Robotics and artificial intelligence (AI) will improve product and service quality, create greater throughput, enhance employee safety, reduce variability, cut waste, and, most increase customer satisfaction.

By Dr. Keshab Panda
The process control system (PCS) ties all the automation elements of a process manufacturing unit together and its performance level and quality is crucial to keep operations running smoothly. Courtesy: Maverick Technologies
PID, APC January 31, 2019

How to select a process control system

Selecting a process control system (PCS) involves experienced personnel and understanding critical elements for operations.

By Lynn Njaa