Description
Compare derivative-on-measurement and derivative-on-error terms.
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.
Compare derivative-on-measurement and derivative-on-error terms.
When to use this tool
Use Derivative On Measurement Setpoint Gap when checking one explicit controller-state or term update.
How to use the tool and how it works
- Enter previousMeasurement, measurement, previousSetpoint, setpoint, derivativeGain, step. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read measurementDerivative, errorDerivative, kickDifference. Use the output convention below.
Compare derivative-on-measurement and derivative-on-error terms. Require step > 0; return -Kd*measurementChange/step, Kd*(setpointChange-measurementChange)/step and kickDifference = Kd*setpointChange/step.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| previousMeasurement | Previous Measurement | Required. Finite number. |
| measurement | Measurement | Required. Finite number. |
| previousSetpoint | Previous Setpoint | Required. Finite number. |
| setpoint | Setpoint | Required. Finite number. |
| derivativeGain | Derivative Gain | Required. Finite number. |
| step | Step duration in the same time unit used by rates and time constants. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| measurementDerivative | Measurement Derivative | Required. Finite number. |
| errorDerivative | Error Derivative | Required. Finite number. |
| kickDifference | Kick Difference | Required. Finite number. |
{
"input": {
"previousMeasurement": 10,
"measurement": 12,
"previousSetpoint": 15,
"setpoint": 20,
"derivativeGain": 2,
"step": 1
},
"output": {
"measurementDerivative": -4,
"errorDerivative": 6,
"kickDifference": 10
}
}Limitations and assumptions
- This uses backward differences without filtering; noise, saturation and practical tuning are not modeled.
- 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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