|
Control
Arts article on controller performance assessment is the most downloaded
paper in the prestigious Journal of Process Control (more...)
AlarmCapture
V5.0 just released! New interface, new capabilities, and support for more
DCS systems (more...).
Control
Arts receives 4 patents for controller performance and alarm management
(more...)
Now
available - three courses for the advanced control engineer on alarm engineering,
model identification, and controller performance assessment (more...)
|
ControlMonitor
- Interactive
The Control Arts ControlMonitor Interactive module enables in-depth
analysis of one or more control loops to determine if a controller
is not performing well, why it is not performing well, and steps to
improve the performance. And because it connects directly to the plant
historians, it's easy to analyze any time period on any tag or tags. |
Analyze any single loop. Included on this display
are the following tests:
- Performance Indices (3 types)
- Measurement/Setpoint/Output Time Trend
- Auto and cross correlation
- Measurement-Setpoint Histogram
- Frequency Response
- Measurement vs. Output plot
|
 |
|
 |
Surge vessel level controllers have different
objectives than flow or temperature loops - the purpose of level
loops isn't to maintain a setpoint, but to dampen variation
in the controlled flow. To assess the performance of these loops,
the ControlMonitor package has a special test that compares
the current performance to an optimal surge vessel level controller
performance. |
|
There may be loops that cycle at common frequencies
in your plant, but it's usually difficult to determine which
loop is causing the cycling. And sometimes the problem
is determining not whether loops are cycling, but which set
of loops are cycling at a common frequency.
The ControlMonitor software package contains state of the
art algorithms designed for just these problems. Common cycling
frequences are determined using spectral envelopes,
while non-linear time series analysis indicates the
likeliest cause of cycling loops. While the math behind both
tests might be sophisticated, interpretation is easy, and
it's not necessary to take any controllers off control or
perform other plant tests. |
|
|
 |
Often the cause of poor performance is just that
the controller needs retuning. And the easiest way to retune
is to make a few open-loop tests then have the ControlMonitor
quickly identify a transfer function model and obtain the tuning
parameters directly from the model. |
|
|
