I was wondering how do you go about installing adv. control?
A picture I have is:
You come as invited specialist, put a data logger
annalyze the data see if you can make improvements, buy off the shelf package/solution and install it or you do model identification(how - which method?) and program some moodern algorithm from a booK to run on industrial PC??
thanks

 

This is what we do:
- You come as invited specialist, discuss the theoretical background of the problem to solve, decide which data is required, put in a data logger
- A model identification package will help you analyse the data and come to a first preliminary model of the equipment.
- This model is loaded in an APC and installed in parralel with the existing control system. Its behaviour is analysed while more data is gathered especially during process disruptions, grade changes and startup.
- The control strategy is discussed and implemented in the controller. This can be a fairly big job as an APC controller controlles all varriables at once. Constraints and priorities of controlled variables are defined. e.g quality has priority over output, safety implies certain boundaries, etc...
- The model is fine tuned and ready for on-line trails, these trails are first conducted when the installation is in steady state and is continued until either an operator manually stops it or the process goes out of a predefined tolerance band.
- Performance tests are executed, typically during grade changes or startup of the equipment, to estimate the improvement caused by the APC.

Basically what you need is a modelling tool and an APC controller capable of using the model that is generated by the modelling tool. Most APC controllers work on the same principle, minimising the cost function of the process. Also note that an APC controller should controll all related parameters together as opposed to PID where you will try to separate them in more or less independent control loops. This means that an APC could control any number of valves simultanuously instead of only 1 or 2.

 

> This is what we do:
> - You come as invited specialist, discuss the theoretical background of the problem to solve, decide which data is required, put in a data logger <

How did you become a rec. specialist and how do you determine that fixing some hardware malfunction is not going to give better performance and advanced conTrol is?
(where have you found the most use for adv.control?)

> - A model identification package will help you analyse the data and come to a first preliminary model of the equipment. <

which package you use and have you tryed designing your own?

> - This model is loaded in an APC and installed in parralel with the existing control system. Its behaviour is analysed while more data is gathered especially during process disruptions, grade changes and startup. <

What do you think of non model control such as www.cybosoft.com?

> - The control strategy is discussed and implemented in the controller. This can be a fairly big job as an APC controller controlles all varriables at once. Constraints and priorities of controlled variables are defined. e.g quality has priority over output, safety implies certain boundaries, etc... <clip><

What apc do you use and what strategies does it offer?

Thanks so much
J.

 

Call me. We'll have a chat. I've been in the business 25 years. 281-256-5555. Rick Guercio, RG Consulting