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Adjust TPA parameters for fixed-wing aircraft #11237

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Merged
sensei-hacker merged 1 commit into from
Jan 10, 2026
+2 −2
Merged

Adjust TPA parameters for fixed-wing aircraft #11237

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2 changes: 1 addition & 1 deletion src/main/fc/settings.yaml
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Original file line number Diff line number Diff line change
Expand Up @@ -1411,7 +1411,7 @@ groups:
default_value: OFF
- name: fw_tpa_time_constant
description: "TPA smoothing and delay time constant to reflect non-instant speed/throttle response of the plane. See **PID Attenuation and scaling** Wiki for full details."
default_value: 1500
default_value: 2000
field: throttle.fixedWingTauMs
min: 0
max: 5000
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2 changes: 1 addition & 1 deletion src/main/flight/pid.c
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Expand Up @@ -446,7 +446,7 @@ static float calculateFixedWingAirspeedTPAFactor(void){
const float airspeed = constrainf(getAirspeedEstimate(), 100.0f, 20000.0f); // cm/s, clamped to 3.6-720 km/h
const float referenceAirspeed = pidProfile()->fixedWingReferenceAirspeed; // in cm/s
float tpaFactor= powf(referenceAirspeed/airspeed, currentControlProfile->throttle.apa_pow/100.0f);
tpaFactor= constrainf(tpaFactor, 0.3f, 1.5f);
tpaFactor= constrainf(tpaFactor, 0.3f, 2.0f);
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@qodo-code-review qodo-code-review bot Jan 10, 2026

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Suggestion: Add a check to ensure tpaFactor is a finite number before the constrainf call to prevent potential propagation of NaN or inf values. [possible issue, importance: 7]

Suggested change
tpaFactor= constrainf(tpaFactor, 0.3f, 2.0f);
float factor = tpaFactor;
if (!isfinite(factor)) {
factor = 1.0f;
}
tpaFactor = constrainf(factor, 0.3f, 2.0f);

return tpaFactor;
}
Comment on lines 446 to 451
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Suggestion: Add a defensive fallback when fixedWingReferenceAirspeed (or the exponent inputs) are invalid/uninitialized to avoid returning extreme/NaN values from powf(). Default to a neutral factor (e.g., 1.0f) when configuration is non-positive or non-finite. [Learned best practice, importance: 6]

New proposed code: 
 static float calculateFixedWingAirspeedTPAFactor(void){
     const float airspeed = constrainf(getAirspeedEstimate(), 100.0f, 20000.0f); // cm/s, clamped to 3.6-720 km/h
     const float referenceAirspeed = pidProfile()->fixedWingReferenceAirspeed; // in cm/s
-    float tpaFactor= powf(referenceAirspeed/airspeed, currentControlProfile->throttle.apa_pow/100.0f);
-    tpaFactor= constrainf(tpaFactor, 0.3f, 2.0f);
+    const float exponent = currentControlProfile->throttle.apa_pow / 100.0f;
+
+    if (!(referenceAirspeed > 0.0f) || !isfinite(referenceAirspeed) || !isfinite(exponent)) {
+        return 1.0f;
+    }
+
+    float tpaFactor = powf(referenceAirspeed / airspeed, exponent);
+    tpaFactor = constrainf(tpaFactor, 0.3f, 2.0f);
     return tpaFactor;
 }


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