Description
Multiply supplied loop-edge signs and label the product's feedback sign.
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.
Multiply supplied loop-edge signs and label the product's feedback sign.
When to use this tool
Use Feedback Loop Sign Product when you already have edgeSigns and need to multiply supplied loop-edge signs and label the product's feedback sign.
How to use the tool and how it works
- Enter edgeSigns. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read loopSign, negativeFeedback. Inspect negativeFeedback before interpreting the associated values.
Require a nonempty list containing only -1 or +1; multiply them, and set negativeFeedback=true for a negative product.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| edgeSigns | Edge Signs | Required. Array of safe integer; maximum items 256. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| loopSign | Loop Sign | Required. Safe integer. |
| negativeFeedback | Negative sign product only, not proof of actual stable or safe feedback. | Required. Boolean. |
{
"input": {
"edgeSigns": [
1,
1,
-1
]
},
"output": {
"loopSign": -1,
"negativeFeedback": true
}
}Limitations and assumptions
- This is a sign-only graph calculation. Actual loop definition and signs are supplied; negative product alone does not establish stable, well-posed or safe feedback.
- 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.
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
- Error Reference Measurement Sign
Choose a supplied reference-versus-measurement error sign convention.
- Equilibrium State Residual
Compare one supplied derivative magnitude with an explicit tolerance.