Update: Here are links to the presentations:
Modeling and Control blog’s Greg McMillan is presenting an ISA Saint Louis Short Course today through Wednesday. Greg describes the course, Exceptional Opportunities – An Interactive Exploration of Process Control Improvement:
To get the most out of your control loop requires the best in instrumentation and process control techniques. This course details the key capabilities of measurements and valves that are most important for loop performance. Methods are provided for easily tuning controllers and determining the effect on process control. The power of PID functionality is demoed and explored in hands-on lab exercises using a virtual plant to provide a faster setpoint response and disturbance rejection. Options such as dynamic reset limiting and a smart PID for wireless will be featured. Free access and instructions for a virtual plant for continued self-learning will be provided. Application problems submitted will be studied for solutions privately or publically based on student’s preference.
Greg was kind enough to share a draft of his slides so I’ll highlight his first day important ten concepts:
- Delay (total loop deadtime) – minimize delay (the loop cannot do anything until it sees and enacts change)
- Speed – make control systems faster and make processes and disturbances slower
- Gain – maximize control system gains (maximize control system reaction to change) and minimize process and disturbance gains (minimize process reaction to change)
- Resonance – make oscillation period slower or control loop faster
- Attenuation – maximize attenuation by increasing volume and mixing and making loops faster
- Sensitivity – Resolution – minimize change measured or manipulated – once past sensitivity limit full change is seen or used but resolution limit will quantize the change
- Hysteresis – Backlash – minimize hysteresis, the bow in a response curve between full scale that traverses in both directions and deadband, the minimum change measured or manipulated once the direction is changed
- Repeatability – Noise – minimize size and frequency of noise and do not transfer noise to process
- Offset – Drift – minimize offset and nonlinearity by smart transmitters and sensor matching and smart tuned digital positioners with accurate internal closure member feedback
- Nonlinearity – minimize nonlinearity by process and equipment design (e.g. reagents and heat transfer coefficients), smart transmitters and sensor matching, valve selection, signal characterization, and adaptive control.
If you’ve not seen any of Greg’s monthly live seminar/demos on these important process control improvement concepts, you can visit our library of recorded video presentations and archived presentations.
Hopefully there are a few nuggets of wisdom to put to use to optimize your process.