Upcoming Events in 2012
March 28-30, 2012
IFAC Conference on Advances in PID Control, PID’12, Brescia
At the IFAC Conference on Advances in PID Control, the following presentations will be given by Willy Wojsznis and Terry Blevins, Emerson Process Management Future Architecture Team.
- Intelligent PID Product Design – Willy Wojsznis, Terry Blevins, John Caldwell, Peter Wojsznis, Mark Nixon
Abstract: This paper outlines intelligent PID design for DCS. The design includes a PID algorithm with diverse standard options and algorithm extensions for wireless/event-driven control and for surge control. The core of the PID intelligence is adaptive process modeling based on model switching and parameter interpolation. The developed process model is applied to loop tuning, adaptive control, loop performance evaluation and valve diagnostics. A user-friendly interface provides insight into a loop’s current state and history events. The interface also provides advice about how to improve loop performance.
- PID Advances in Industrial Control – Terry Blevins (plenary presentation)
Abstract: Major advances that improve control in the process industry have been made over the last ten years in the basic PID technology of modern distributed control systems. This paper addresses the impact that international standards have on control implementation and the tools utilized in industry for monitoring and commissioning PID control. Examples are used to illustrate how new technologies, such as model switching for process identification, have allowed manufacturers to introduce a new level of ease-of-use in tools developed for on-demand and adaptive tuning. This paper discusses PID modifications that improve the speed of recovery from process saturation conditions that are common in industrial applications. Also, details are provided on PID modifications that enable effective control with non-periodic measurement updates by wireless transmitters. Finally, prospective future directions for industrial PID controllers are sketched.
- Improving PID Recovery from Limit Conditions – Terry Blevins, Dan Coyne(BP), Willy Wojsznis, Mark Nixon
Abstract: This paper addresses the performance of the PID under startup or during normal operation when the PID output becomes limited. Common techniques that have been utilized to reduce the time required to get to setpoint during process startup are reviewed. The response of the PID to conditions that limit PID operation during normal operating conditions is discussed for different implementation approaches. In particular under limiting conditions, anti-reset windup is automatically activated when a positive feedback network is used to create the reset contribution. For such implementations, the recovery from a process saturation condition may be improved by modifying the PID operation. An application example is used to show the impact of this modification on response speed and overshoot.
May 14-18, November 5-9, 2012
Terry Blevins will teach the 9025 class, Control Loop Foundation Class, Emerson Education Department, Austin, TX. This class is based on the book Control Loop Foundation. Below is an outline for this class:
Course 9025 CEUs: 3.2
This course is for engineers, managers, technicians, and others that are new to process control. This course includes the practical aspects of control design and process applications that course developers personally learned through years of hands on experience while designing and commissioning process control applications.
This 4-1/2 day course for personnel new to automation and covers process control fundamentals as well as the practical aspects of control system design and applications. Upon completion of this course the student will be able to effectively work with and commission single and multi-loop control strategies. Interactive workshops allow the student to apply what they learn in the class
June 27 – 29, 2012
American Control Conference (ACC), Montréal
The conference will be the first ACC outside of the United States. Professor Ricardo Dunia, UT, Austin, will present the following papers on work funded by Emerson on continuous data analytics.
- Multistate PCA for Continuous Processes – Ricardo Dunia, Vinay Kumar, Thomas F. Edgar, Terry Blevins and Willy Wojsznis
Abstract: Multiway PCA and multiblock multiway PLS have significantly enhanced process monitoring of batch processes by providing expected trajectory profiles for process variables along the batch duration. However, continuous processes lack of an equivalent technology because of their flexible operations and undefined time duration. This work presents a novel methodology to define operating regions where continuous processes operate. Such operating regions are determined by special variables, named state variables. Transition trajectories between regions or states of operation are calculated to determine the most likely profile in terms of state variable changes. This methodology can be implemented in the context of empirical monitoring methods, named Multistate PCA. A case study that make use of CO2 capture process data shows how this methodology could enhance fault diagnostics and statistical monitoring for continuous processes.
- Multistate PLS for Continuous Processes – Ricardo Dunia, Thomas F. Edgar, Terry Blevins and Willy Wojsznis
Abstract: Batch process monitoring methods, such as multiway PCA and multiblock multiway PLS, make use of time profiles to define expected process variable trajectories for statistical process control. Nevertheless, continuous process counterpart methods of desired process variable profiles have not been developed, nor addressed in the literature. This work presents a novel methodology to define multiple operating points around which continuous processes operate. Process operating regions are divided into multiple states of operation and shifts in operating conditions are captured by special variables, named state variables. Transition trajectories between states are calculated to determine the most likely path between states. This methodology can be implemented in the context of empirical monitoring methods, named Multistate PLS. A case study shows how this methodology enhances fault diagnostics and statistical monitoring of continuous processes.