EasyIO PRAC+ adaptive tuning

easyio prac

The latest release information for EasyIO PRAC+. Pattern Recognition Adaptive Control (PRAC+) is a patented Johnson Controls technology for automatic PID tuning. PRAC+ cuts commissioning time – as does its extensive list of predefined, selectable control loops. Plus, there’s no need for manual retuning; as conditions change, EasyIO automatically brings controls back to the optimal settings.

EasyIO PRAC+ release: cut commissioning time, save energy, improve control

EasyIO featuring Pattern Recognition Adaptive Control (PRAC+). This patented Johnson Controls technology for automatic PID tuning cuts commissioning time – as does our extensive list of predefined, selectable control loops. Plus, there’s no need for manual retuning; as conditions change, EasyIO automatically brings controls back to the optimal settings.

Adaptive tuning vs offline

PRAC+ examines the control loop output and system response when the PID is active and continuously adapts the tuning parameters of proportional band and integral time. If the oscillatory response is large, the tuning parameters adjust to make the response slower. If the response is small and the error is large, the tuning parameters adjust to make the response faster. PRAC+ adaptive tuning responds when loads change due to any of the following factors:

  • Time of day
  • Day of week
  • Season
  • Heat exchanger or chiller fouling
  • General wear and tear of system components, such as valves and dampers
  • Setpoint changes
  • Time of day
  • Day of week
  • Season
  • Heat exchanger or chiller fouling
  • General wear and tear of system components, such as valves and dampers
  • Setpoint changes

    During this process, PRAC+ monitors the process variable for patterns that contain tuning information, extracts features from those patterns, and uses the features to determine the optimal tuning parameters. PRAC+ then steps the tuning parameters toward the optimal values, based on the relative size of the present pattern compared to past patterns.

    PRAC+ adaptive tuning provides the following benefits:

    • The time required to tune new control systems is reduced or eliminated.
    • The time required to retune control systems due to changes in seasons, loads, or equipment performance is eliminated.
    • Fewer oscillations cause less wear and equipment life is increased.
    • Energy use decreases with stable control loops. Oscillatory control behavior causes unnecessary preheating or mechanical cooling.
    • More accurate control system performance improves comfort.
    • Safety improves in environments where safety systems are dependent on the performance of HVAC control systems, such as hospitals and laboratories.