GMAXC, Multivariable Controller

Source: Intelligent Optimization, Inc.
Multivariable Predictive Control (MVPC) technology has become a norm for controlling continuous chemical processes
Multivariable Predictive Control (MVPC) technology has become a norm for controlling continuous chemical processes. But, its implementation has been slow in some chemical industries because of high costs and engineering resources requirements. To overcome these limitations, GMAXC is designed to offer MVPC technology at a commodity level for rapid assembly line type implementation.

We believe, it will offer you an unsurpassed value as you automate your process units. As a fully integrated package, it includes (some modules may be optional):

  • GMAXCID, for dynamic model identification with minimal plant test data collection
  • GMAXCON, for online PC Based Control (this module is available for other computer platforms also)
  • GMAXCDDE, for simplified fill-in-the-blanks type configurable DDE Interface with plant DCS systems
  • GMAXCWIZ, a Wizard for cloning controllers with generic models from a template library. The generic controller can then be made specific by fine tuning (or replacing) the models, and entering the appropriate process values and limits.
  • GMAXC - HYSYS Interface: Avoid costly plant tests by using Hyprotech's HYSYS Dynamic Simulator as a virtual plant to help identify dynamic models and test controller performance.
  • Demo/Example: A generic refinery crude unit controller is included for practice and help in understanding how to design and develop a MVPC controller.

In our efforts to make this a commodity technology, GMAXC can also be used to replace other MVPC controllers to simplify maintenance. As a step towards new generation control technology, it offers an upward migration path to the Intelligent Controller, I-GMAXC. The I-GMAXC has the capability to control a process from start-up to shut-down including emergency actions, MVPC, nonlinear control, etc., in one unified controller. Previous investments in MVPC controllers is retained as they can be conveniently migrated to GMAXC and I-GMAXC.

Key Benefits

  • Low Cost Hardware/Software investment while achieving full benefits of MVPC technology
  • Rapid Implementation with minimal plant testing (typically 12 hours for every 5 independent variables)
  • In-house implementation and maintenance of MVPC technology


  • Windows based intuitive interface allows ease of controller formulation in terms of safety, quality and economic goals
  • Integration of Optimization (nonlinear) with dynamic control
  • Simplified process identification with heuristic based data validation and collation
  • Capability to handle continuous, discrete and integrating variables
  • Full online tuning capability, even dynamic models can be fine tuned online
  • Dual penalties for Quality Goals/Controlled variables to allow both quality and economic goals
  • Scaling and transform (e.g. log ) options for variables
  • Controllability Index calculation to check for feasible control matrix formulation
  • Controller simulation allows addition of noise to check control performance and robustness

Platform Availability

  • PC Windows NT and 95/98 executable
  • PC Windows NT and 95/98 DLL
  • HP-Unix
  • Moore Products APACS DCS Function Block

Intelligent Optimization, Inc., P.O. Box 79162, Houston, TX 77279. Tel: 713-849-0455; Fax: 713-849-0455.