BIAS - APMonitor Option

Main.OptionBias History

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June 08, 2017, at 10:26 PM by 10.5.113.159 -
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June 06, 2017, at 09:52 PM by 10.5.113.159 -
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BIAS is additive factor that incorporates the difference between the current measured value and the initial condition of the controller. [[Main/OptionFstatus]] determines how much of the raw measurement is used to update the value of [[Main/OptionMeas|MEAS]]. A feedback status of 0 indicates that the measurement should not be used and the BIAS value is . A feedback status of 1 uses all of the measurement. A feedback status in between 0 and 1 updates MEAS with a fractional contribution from LSTVAL and the new measurement. The value of BIAS is updated from [[Main/OptionMeas|MEAS]] and the unbiased model prediction (Model_u).
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BIAS is additive factor that incorporates the difference between the current measured value and the initial condition of the controller. [[Main/OptionFstatus|FSTATUS]] determines how much of the raw measurement is used to update the value of [[Main/OptionMeas|MEAS]]. A feedback status of 0 indicates that the measurement should not be used and the BIAS value is kept at the initial value of 0. A feedback status of 1 uses all of the measurement in updating [[Main/OptionMeas|MEAS]]. A feedback status in between 0 and 1 updates [[Main/OptionMeas|MEAS]] with a fractional contribution from [[Main/OptionLstval|LSTVAL]] and the new measurement. The value of BIAS is updated from [[Main/OptionMeas|MEAS]] and the unbiased model prediction (Model_u).
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The value of BIAS can also be set to an external ''value'' by setting the option ''apm_option(s,a,'CV.BIAS',value)'' and setting [[Main/OptionFstatus|FSTATUS]] to 0 (OFF).
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The value of BIAS can also be set to an external ''value'' by setting the option ''apm_option(s,a,'cv.BIAS',value)'' and setting [[Main/OptionFstatus|FSTATUS]] to 0 (OFF).
June 06, 2017, at 09:50 PM by 10.5.113.159 -
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(:title BIAS - APMonitor Option:)
(:keywords BIAS, Optimization, Estimation, Option, Configure, Default, Description:)
(:description Controller additive bias is a correction factor to align the controller output to an available measurement:)

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 Type: Floating Point, Input/Output
 Default Value: 0.0
 Description: Additive correction factor to align measurement
              and model values for Controlled Variables (CVs)

BIAS is additive factor that incorporates the difference between the current measured value and the initial condition of the controller. [[Main/OptionFstatus]] determines how much of the raw measurement is used to update the value of [[Main/OptionMeas|MEAS]]. A feedback status of 0 indicates that the measurement should not be used and the BIAS value is . A feedback status of 1 uses all of the measurement. A feedback status in between 0 and 1 updates MEAS with a fractional contribution from LSTVAL and the new measurement. The value of BIAS is updated from [[Main/OptionMeas|MEAS]] and the unbiased model prediction (Model_u).

 BIAS = MEAS - Model_u

The BIAS is added to each point in the horizon and the controller objective function drives the biased model (Model_b) to the requested set point range.

 Model_b = Model_u + BIAS

The value of BIAS can also be set to an external ''value'' by setting the option ''apm_option(s,a,'CV.BIAS',value)'' and setting [[Main/OptionFstatus|FSTATUS]] to 0 (OFF).

See also [[https://apmonitor.com/do/index.php/Main/EstimatorObjective|Estimation Objective Tuning]]