Control error
Also: tracking error
The signed difference between desired and measured output.
With convention e = r−y, sign determines corrective action; sensor bias means computed error may differ from true error.
- Units
- same as controlled quantity
- Formula
e = r − y
Example A 100 rpm target and 92 rpm measurement give +8 rpm error.
Common misconception Zero measured error does not prove physical truth when sensing is biased or saturated.