Browse Prior Art Database

Simple Adaptive Control Scheme

IP.com Disclosure Number: IPCOM000244181D
Publication Date: 2015-Nov-20
Document File: 4 page(s) / 102K

Publishing Venue

The IP.com Prior Art Database

Related People

Boliang Yi: INVENTOR [+2]

Abstract

Many if not all industrial processes are subject to significant changes over the lifespan of the corresponding plant These may be due to ageing wear retrofitting modernization changing tasks etc In almost all processes the performance is guaranteed through the use of a properly set feedback control system In general this accounts for disturbances and deviation of the process from its nominal behavior However the aforementioned changes might be too large to be covered with the same controller set up parameterization Hence adaptation of the parameters is needed to keep the process on track In the following a very simple way of adapting a controller is presented It is based on simplifying the process dynamics to that of a double integrator robustly controlling this double integrator and adapting to the process changes by using a disturbance estimator based signal differentiation This will result in a very simple closed loop control structure with simple but highly robust elements dedicated for industrial purposes

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 35% of the total text.

Page 01 of 4

DE-1314701

Invention Disclosure Draft

Inventors:

Abstract

Many if not all industrial processes are subject to significant changes over the lifespan of the corresponding plant. These may be due to ageing, wear, retrofitting / modernization, changing tasks etc. In almost all processes the performance is guaranteed through the use of a properly set feedback control system. In general this accounts for disturbances and deviation of the process from its nominal behavior. However, the aforementioned changes might be too large to be covered with the same controller set-up / parameterization. Hence, adaptation of the parameters is needed to keep the process on track. In the following, a very simple way of adapting a controller is presented. It is based on simplifying the process dynamics to that of a double integrator, robustly controlling this double integrator and adapting to the process changes by using a disturbance estimator based signal differentiation. This will result in a very simple closed-loop control structure with simple but highly robust elements dedicated for industrial purposes.

Benefits

Deriving an adaptive control law for a changing process is far from trivial and typically needs cautious adjustments and a high expertise. Even though most adaptive controllers to date are designed to solve the adaptation for a single process they cannot guarantee closed-loop stability. This questions the high effort needed for their installation.

The described invention disclosure will simplify the design process and enable the worker itself to set-up / parameterize the controller. One of the main reasons for that being the reduction to the design of a double integrator controller. Since the adaptation is done by a disturbance estimation based on a (numeric) signal differentiator, the controller parameters do not need to be changed at all even though the process may vary vastly. At the end, this will not give any guarantees for the closed-loop stability but practical stability is obtained and the effort is reduced greatly.

Kim Listmann, Boliang Yi

Last Change: 2013-07-31

Title:
Simple Adaptive Control Scheme

Alternative Title: Adaptive Controller based on Derivative Estimation

Log of Progress:


.2013-07-31 first draft entered into ID data base


.


Page 02 of 4

Technical Problem to be solved

The change of the dynamic behavior of an industrial process over the course of time is unavoidable. Many of these changes are rather small and only lead to little deviations from the original behavior. These are typically covered by the robust (PID) controllers in place today and nobody even notices. However, if the changes reach a significant value such controllers must be retuned to conserve the closed-loop performance. Since the typical PID loop contains many more elements than the controller itself (e.g. lead/lag/notch filters, anti-windup) this can be a tedious task with lots of cross-sensitivity of the elements in place.

This can be avoided on...