Process Control Improvement with Mimic v3.6.2
By Martin Berutti on 10.28.15
Mimic Simulation

Life Cycle Dynamic Simulation is a proven technology to support process control and operational improvement. The Mimic v3.6.2 release includes new functionality that makes improving plant operations easier and better.

Mimic Rough-N-Ready Tuner and ePID blocks make process control improvement initiatives quicker and more profitable.

These additions to Mimic in v3.6.2 include a new function block toolkit for process control improvement, new functions to support Rockwell RSTestStand™ users, and the next generation of the Mimic External Modeling Interface (or MEMI).

Process Control Improvement Toolkit

Process control improvement including better measurements, control valves, PID tuning, and control strategies can be explored, developed, prototyped, tested using Mimic. The dynamics provided by the new function blocks in Mimic v3.6.2 can be used to simulate the dynamics of control system components with the results documented with online process metrics in Mimic. This library of control system components in Mimic is based upon the more than 100 articles and papers and 20 books by Gregory K McMillan most completely in the recent Momentum Press book Tuning and Control Loop Performance 4th Edition.

Also, added to Mimic 3.6.2 release is a pH probe block that can easily, rapidly and robustly model the response of nearly all pH systems. The probe block provides a first principle solution by means of a charge balance shown in McMillan’s book Advances in pH Measurement and Control 3rd Edition. The charge balance, which can handle any number of acids and bases with one to three dissociation constants and has been used for decades by the author to simulate pH systems, has been extended to include the significant buffering effect of monovalent, divalent, and trivalent conjugate salts.

The improvements are easily implemented by simply configuring the new Mimic blocks using the key parameters defined in the ISA Dictionary that are critical to loop performance in the process industry. The new Mimic blocks include the following control components:

  • Analyzer (cycle time, analysis time, resolution, threshold sensitivity)
  • Actuator (deadband, delay, lags, resolution, slew rate, threshold sensitivity)
  • PID (anti-reset windup- output and setpoint limits, back calculate, external reset feedback, modes, output tracking, smart preload, structures, tuning settings)
  • Ratio Controller (actual ratio, back calculate input, bias: feedforward summer, external reset feedback, output and setpoint limits, remotely set ratio: feedforward multiplier, operator set ratio for startup)
  • Rough-n-Ready Tuner (deadband, cycles, noise band, step size, ultimate gain & ultimate period factors)
  • Wireless transmitter (default update rate, trigger update rate, trigger level)

Using Mimic, process control engineers can build effective dynamic simulations, for selecting the best analyzers, control valves, transmitters, and PID controllers and best strategies and tuning settings.

Rockwell RSTestStand™Replacement

One of the goals of Mimic v3.6.2 has been to complete the work we started, in partnership with Rockwell Automation, to allow a migration path for users of Rockwell RSTestStand™ to Mimic. While we had a great migration solution that was used by several RSTestStand™ customers, in v3.6.2 we have released a set of blocks that now provide a one-to-one functionality equivalent for RSTestStand™. For every RSTestStand™ block there is now an equivalent Mimic block. The new blocks added for RSTestStand™ users in Mimic v3.6.2 are:

  • Analog Valve
  • Generic VFD
  • Message Array
  • Motor Operated Valve
  • Momentary Latched MOV
  • On Off Valve
  • Rotary Axis
  • Simple Axis
  • Velocity Position

Any Model Is A Mimic Model - MEMI 2.0

Included in Mimic v3.6.2 is a powerful tool for integrating any third party model into Mimic and using this custom model in the Mimic dynamic simulation environment. The Mimic External Modeling Interface (or MEMI) has been released with additional model integration and synchronization capabilities and user awareness and controls in Mimic Diagnostics and Simulation Studio. External models that can be integrated into Mimic using MEMI include models developed in MS Visual Studio in C, C++, or Visual Basic, or models developed in process design platforms such as HYSYS or MatLab.

External custom models integrated in Mimic Explorer using MEMI.

Mimic v3.6.2 will be released the first week of December 2015. Mimic users current on Mimic Software Support can upgrade to Mimic v3.6.2 at no additional charge. This release of Mimic extends the value of dynamic simulation, providing additional life cycle benefits for process plants. The value of dynamic simulation is proven. Mimic v3.6.2 delivers greater business results for less time and money.

More Information on Life Cycle Results with Mimic

I look forward to your comments, questions, or suggestions.

Hope to hear from you soon.

Mart Berutti, 11/30/15