Apromon is an online software product for monitoring the PID loop control performance of primary and Advanced Process Control (APC) loops. Apromon evaluates single loops, cascade loops, any Advanced Process Control (APC) loops and even signals that have PV only but no controller associated them.
Apromon has the unique power to automatically convert flow controllers, pressure controllers, temperature controllers, level controllers, online analysis controllers, any Advanced Process Control (APC) controller into a single “grade” factor, just like the grade given by a professor to a student on a test or an examination. 100 indicates best performance and 0 indicates the worst.
Some of the distinguishing and powerful features of Apromon are listed below:
- Runs automatically every set period so that performance is always being calculated and archived
- Runs all the time, does not skip any period for any tag like some competitor products
- Calculates over 25 performance criteria for every tag
- Equipped with a powerful online oscillation detection feature that includes both hunting and instability
- Stores all 25 performance criteria in a historical archival system, trendable online
- All types of control loops – fast, medium, slow are automatically, intelligently scaled appropriately
- Grade performance is displayed as an online real-time trend
- If the Grade is changing, control engineers see it immediately on a dedicated Grade screen
- Data interface is using simple Excel interface, no need for expensive server-client architecture
- Can be run for any number of loops with multiple instances, if necessary on existing PCs
- Each control engineer can have his own version/instance of Apromon running on individual PC
- Generates automatically a detailed and summary report every time it runs
- Detailed/summary report and the online Grade trend helps identify poor loops immediately
- Reports can be conveniently used during morning meetings in control room for prioritization
Figure 1 shows the online Apromon program access screen. It shows the scheduled time of the next run.
The program can be made to run as fast as every 15 minutes though typically an auto-run every 2-6 hours is more common. Clicking on the “Show Grade Trends” displays Figure 2 showing the current and past historical Grade of tags selected by the user.
Apromon displays 25 different performance criteria for every tag. The Grade reported for each tag is a function of these criteria. Some of the performance criteria are displayed in Figure 3. Apromon also assigns a text descriptive message describing the performance of the tag; e.g. “Control performance is satisfactory”, “Loop oscillates- high (PV-SP) error” etc., see Figure 4 for an illustration. These messages and the Grade are extremely valuable and are stored in the historical archival system that comes with Apromon. The user can easily access the text message and the Grade for months and years.
Figure 5. Internal Model Controller (IMC) and Dead Time Compensation (DTC)
Apromon is equipped with leading-edge technology for oscillation detection. Apromon identifies “True Amplitudes” by decomposing a plant signal into its true signal and isolating any noise and signal strength not related to the process. Apromon also comes with a one-of-kind Spectrum analysis algorithm. The true-amplitude-detection (TAD) arrays and Spectrum distribution are shown in Figure 5. This technology is not available in any other software product. Furthermore, Apromon reliably determines if any of the loops are starting to hunt (oscillate) or become unstable with growing amplitudes.
Configuration and implementation of Apromon is very simple and quick. Configuration parameters are shown in Figures 6 and 7. The entire process of configuring Apromon and getting it to work takes only about 4 hours. All data interface is via easy-to-use screens and with standard Excel-based data exchange.