Sampling Theory -
Posted: Sun Dec 03, 2000 1:58 pm
>Im currently modeling organisational behaviour and Im looking for the
>connection of sampling time (delta T) and systems stability.
>What is the impact of increasing delta T on the systems stability. Im
>using Routh Stability test but Im afraid it would not work in my case
>because my delta T can be extremely high.
It is not clear here why, "delta T can be extremely high." The solution
interval should be a small fraction (like a quarter or an eighth) of the
shortest delays and time constants in the system being simulated. As a
test, reduce the solution interval until further reduction has no important
effect on the simulation.
Is there an implication that the "extremely high" solution interfal is
being set by the frequency of some data source? If so, I believe such
should not be a criteria.
For more on the solution interval see the eight pages in Section 6.2 of:
Forrester, J. W. (1968). Principles of Systems. Waltham, MA, Pegasus
Communications.
Pegasus Communications, Inc.
One Moody Street
Waltham, MA 02453-533
tel: 781-398-9700
fax: 781-894-7026
or see pages 903 to 911 of Stermans new book:
Sterman, J. D. (2000). Business Dynamics: Systems Thinking and Modeling for
a Complex World. New York, Irwin: McGraw-Hill.
---------------------------------------------------------
Jay W. Forrester
From: "Jay W. Forrester" <jforestr@MIT.EDU>
Professor of Management
Sloan School
Massachusetts Institute of Technology
Room E60-389
Cambridge, MA 02139
>connection of sampling time (delta T) and systems stability.
>What is the impact of increasing delta T on the systems stability. Im
>using Routh Stability test but Im afraid it would not work in my case
>because my delta T can be extremely high.
It is not clear here why, "delta T can be extremely high." The solution
interval should be a small fraction (like a quarter or an eighth) of the
shortest delays and time constants in the system being simulated. As a
test, reduce the solution interval until further reduction has no important
effect on the simulation.
Is there an implication that the "extremely high" solution interfal is
being set by the frequency of some data source? If so, I believe such
should not be a criteria.
For more on the solution interval see the eight pages in Section 6.2 of:
Forrester, J. W. (1968). Principles of Systems. Waltham, MA, Pegasus
Communications.
Pegasus Communications, Inc.
One Moody Street
Waltham, MA 02453-533
tel: 781-398-9700
fax: 781-894-7026
or see pages 903 to 911 of Stermans new book:
Sterman, J. D. (2000). Business Dynamics: Systems Thinking and Modeling for
a Complex World. New York, Irwin: McGraw-Hill.
---------------------------------------------------------
Jay W. Forrester
From: "Jay W. Forrester" <jforestr@MIT.EDU>
Professor of Management
Sloan School
Massachusetts Institute of Technology
Room E60-389
Cambridge, MA 02139