| 摘要 |
The control method uses the following scheme: Control Value (CV)=Proportional Value (PV)+Derivative Value (DV)+Derivative Correction (DC), where PV goes from 0 to MAX and operates over a very narrow band—in a temperature control example plus or minus 1 degree C. from the setpoint and is used to stabilize CV and enforce the setpoint. DV goes from −MAX to MAX and is exponentially decayed over a time constant to weigh the most recent values heavier than older values. This allows the control to see the real derivative despite a large step size which might otherwise mask it and within a small time window. DC goes from −MAX to MAX and makes this scheme work for any situation. The desired derivative is defined based on the graph. This then adjusts to compensate when the slope is not following the ideal definition.
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