PID, APC - Control Engineering

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

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.

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

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

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