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Controls and Commissioning

1 tool in the Building Systems area.

Control Loop Tuning

PID tuning of a building-services control loop from a first-order-plus-dead-time (FOPDT) or second-order (SOPDT) process model, or from a pasted open-loop step response fitted by the two-point method and by least squares; every classical rule side by side (Ziegler–Nichols reaction curve and ultimate gain of 1942, Cohen–Coon, IMC, SIMC, Tyreus–Luyben) with the settings in the ideal, parallel or series controller form; the ultimate gain and period from the phase crossover; a closed-loop simulation of the setpoint and load responses with overshoot, rise and settling times, decay ratio, IAE / ISE / ITAE and the controller travel; the open-loop Bode plot with the gain and phase margins and the sensitivity peak; and the HVAC specifics: valve or damper authority with the installed characteristic, the proportional thermostat's gain and offset from its throttling range, and sample-time guidance. The default case is the FOPDT process K = 2, τ = 10 min, θ = 2 min (illustrative; the test script also reproduces the worked case of Ziegler and Nichols' 1942 paper and Skogestad's 2003 performance table).

1 worked example reproduced, listed on the tool page.

Other Building Systems sections

HVAC Loads · Ducts and Airflow · Psychrometrics · HVAC Equipment · Ventilation and Air Quality · Energy · Plumbing · Fire Protection · Lighting and Electrical · Codes and Compliance