ExperTune Inc. now provides the capability to tune cascade control loops directly from the Web browser interface of the PlantTriage Loop Performance Monitor. This is designed to streamline the tuning process, according to ExperTune's Founder John Gerry.
The PlantTriage system monitors control system performance continuously, 24 hours a day. It automatically diagnoses and prioritizes process, control, and instrumentation problems. Integrated analysis and tuning tools improve plant results by focusing effort on the most critical issues.
Typical cascade control loops involve two instruments, two controllers and a single control valve or variable-speed drive. Cascade controls are designed to reduce variation, by offering faster response to process upsets. The outer loop provides a set point to the inner loop.
The new tools allow users to tune both loops with a single bump test directly from a Web browser interface. Oscillations are eliminated because the PlantTriage tools select tuning constants that are outside the range of interaction. The new tools are also fully integrated with PlantTriage's Active Model Capture technology, so dynamic models and controller tuning can be developed based on normally-occurring events, such as operator set-point changes.