ControlSoft Advances the Use of Model-Based Control Technologies for Integrating Processes

Highland Heights, Ohio - The U.S. Patent Office has granted ControlSoft Inc. a patent (No. US 7,949,415 B2) for its improvements in applying model-based advanced process control technologies (MAPC) for Integrating Processes.

Integrating Processes, the opposite of self-regulating processes, do not naturally settle out at a steady-state operating level; instead, the controlled variable continues to increase or decrease (integrate). Level, pH, and some temperature processes typically demonstrate these characteristics. Over the years a multitude of complex solutions have been proposed and implemented to manage the challenges of controlling Integrating Processes.

ControlSoft's newly patented extension to its MAPC suite addresses the drawbacks in published common solutions by reducing the design and computational complexities. The improvements are implemented in a relatively simple manner, yet provide a high degree of numerical stability for the control solution.

Tien-Li Chia, Ph.D., President of ControlSoft Inc. and principal inventor of this technology, explains, "This patent addresses the difficulties of Internal Model-based Control (IMC) for Integrating Processes. It enables the use of a simple first order filter as a tuner without steady-state errors; it also enables one to tune for a desirable transient response."

IMC has many advantages over PID control, and has been successfully applied in various processes, such as wastewater treatment, pulp and paper manufacturing, and kiln, dryer, glass, and furnace applications.

MAPC functionality is available in ControlSoft MANTRA software; it is licensed by Rockwell Automation for RSLogix5000* and by several other DCS manufacturers. (Check with ControlSoft for list of available platforms.) The MAPC suite, which includes the IMC, CC, and MMC controllers, provides much improved performance over PID controllers in most applications.

Internal Model Control Block (IMC) has a single input (Process Variable, PV) and a single output (known as Control Variable, CV, or Control Output, CO). It is comparable to and a direct replacement for a PID controller.

Instead of using PID parameters, IMC controls the process by using model parameters (model gain, model lag time constant, model deadtime).
IMC provides much improved control performance over PID control if there is some deadtime in the process (10 seconds or more).

Coordinated Control Block (CC) (single input, 3 outputs) is the most effective and most widely used MAPC block as almost all processes are multivariable in nature (for example, they all have disturbances). Two of the three CVs can be either active CV or measurable disturbances.

CC provides much improved control performance in the following situations:

a. processes with long deadtime,

b. processes with measurable disturbances,

c. processes with two or more CVs such as heat/cool controller.

In the case of multiple CVs, CC can provide fastest response while maximizing the use of lower-cost fuel. CC optimizes both performance and economic benefits.

Modular Multivariable Control Block (MMC) (2 inputs, 3 outputs) is a small multivariable controller that is intended for small process units.

MMC effectively addresses the process dynamic interactions. Not only will it maintain the setpoint for two PVs, it will maximize the use of lower-cost CV. Hence, it maximizes both performance and economic benefits.

MMC and CC provide the most effective way of handling process constraints.

o The MAPC functions (IMC, CC, MMC) are licensed by Rockwell Automation, and are available on RSLogix5000 (V.17 and later) as embedded functions.

Applications that can benefit significantly by using MAPC include:

o Chlorination in water & de-chlorination & DO control in WWTP

o Fermentation & dissolved oxygen control

o Glass forehearth & furnace control

o Dryer & evaporator control

o Cooking station feed & temperature control

o Pulp & paper, basis weight & moisture control

o pH & ORP control

o Autoclave pressure & temperature control

o Engine test stand, speed & power control

o Boiler control

o Kiln & moisture control

o Distillation & separation processes

o Chemical reactor, pressure & temperature control

For further information on IMC [DS311], CC [DS312], or MMC [DS313], request data sheet via email:

ControlSoft Inc.


o ControlSoft Inc. specializes in advanced control solutions for the process industries. A leader in model-based control for process applications, ControlSoft was founded in 1985, and is headquartered in Highland Heights, Ohio.

ControlSoft's proven PC-based software products work with existing control systems:

o INTUNE Version 5 and INTUNE+ Process Navigator for process control monitoring, tuning, online diagnostics, and automatic reporting on poor performance;

o MANTRA for advanced process control systems, using model predictive techniques to improve profitability and quality.

MANTRA® and INTUNE® are registered trademarks of ControlSoft Inc.
ControlSoft offers custom engineering services, including onsite tuning, consulting, studies, and training in control loop optimization and control strategies.

Learn more: visit
email to; call 440-443-3900.

ControlSoft, Inc.

5387 Avion Park Drive

Highland Heights, Ohio 44143



Paul Botzman -

phone 440-443-3900, ext. 101

More from Machinery & Machining Tools

All Topics