Description
Choose a supplied reference-versus-measurement error sign convention.
Control terms depend on error sign, units, sample timing, saturation direction and state conventions. Hysteresis retains state between thresholds, while deadband mapping and output clamping describe different operations. A negative loop-sign product or small scalar derivative does not establish closed-loop stability or safe operation.
Choose a supplied reference-versus-measurement error sign convention.
When to use this tool
Use Error Reference Measurement Sign when you already have reference, measurement, convention and need to choose a supplied reference-versus-measurement error sign convention.
How to use the tool and how it works
- Enter reference, measurement, convention. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read error. Use the output convention below.
Require convention reference-minus-measurement or measurement-minus-reference; perform the corresponding subtraction.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| reference | Reference | Required. Finite number. |
| measurement | Measurement | Required. Finite number. |
| convention | Convention | Required. Text; one of "reference-minus-measurement", "measurement-minus-reference"; maximum UTF-16 length 8192. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| error | Error | Required. Finite number. |
{
"input": {
"reference": 10,
"measurement": 8,
"convention": "reference-minus-measurement"
},
"output": {
"error": 2
}
}Limitations and assumptions
- Units and frames must already match. No reference is selected, sensor verified, controller tuned or safe error limit established.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use a complete plant, controller, actuator and timing model with verified operating constraints for control decisions. Check interactions among saturation, integrator state, gains and delays; individual algebraic terms do not tune a controller or validate system stability or safety.
References
Similar or alternative tools
- Sensor Reference Frame Sign Choice
Reverse a supplied sensor value under an axis flag.
- Control Reference Unit Dimension Pair
Compare supplied unit and dimension tokens literally.