Description
Return previous-output weight for one derivative-filter discretization.
Controller calculations combine state, gain, error and reset conventions. A one-step update or output-balance target describes one part of a controller and does not implement, tune or establish the stability of a complete plant-control loop.
Return previous-output weight for one derivative-filter discretization.
When to use this tool
Use Cybernetics: Derivative Filter Coefficient Reference when checking one explicit controller-state or term update.
How to use the tool and how it works
- Enter timeConstant, samplePeriod, discretization. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read result. Expand result to inspect the returned fields.
Return previous-output weight for one derivative-filter discretization. Require positive timeConstant/samplePeriod and backward-euler or exact-decay; choose tau/(tau+T) or exp(-T/tau).1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| timeConstant | Positive time constant, in the same time unit as the step or sample period. | Required. Finite number. |
| samplePeriod | Sample Period | Required. Finite number. |
| discretization | backward-euler uses tau/(tau+T); exact uses exp(-T/tau). | Required. Text; one of "backward-euler", "exact-decay". Implementation limit: 8192 Unicode code points and 16384 UTF-16 code units. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Returned object; expand its named members below. | Required. Object. |
| result.previousOutputWeight | Returned scalar filter coefficient, not a complete filter execution. | Calculated result member: number. |
{
"input": {
"timeConstant": 1,
"samplePeriod": 1,
"discretization": "backward-euler"
},
"output": {
"result": {
"previousOutputWeight": 0.5
}
}
}Limitations and assumptions
- This is one coefficient, not complete filter dynamics or evidence that two discretizations are interchangeable.
- Outputs are nested inside result. 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 the full controller and plant model, numerical implementation and qualified verification for actual operation or transitions.
References
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