Cleanup code // add unittestst for iterm windup

src/main/flight/mixer.c

@@ -361,15 +361,6 @@ bool mixerIsTricopter(void)
 #endif
 }
 
-bool mixerIsOutputSaturated(int axis, float errorRate)
-{
-    if (axis == FD_YAW && mixerIsTricopter()) {
-        return mixerTricopterIsServoSaturated(errorRate);
-    }
-
-    return motorMixRange >= 1.0f;
-}
-
 // All PWM motor scaling is done to standard PWM range of 1000-2000 for easier tick conversion with legacy code / configurator
 // DSHOT scaling is done to the actual dshot range
 void initEscEndpoints(void)

src/main/flight/mixer.h

@@ -117,7 +117,6 @@ struct rxConfig_s;
 uint8_t getMotorCount(void);
 float getMotorMixRange(void);
 bool areMotorsRunning(void);
-bool mixerIsOutputSaturated(int axis, float errorRate);
 
 void mixerLoadMix(int index, motorMixer_t *customMixers);
 void mixerInit(mixerMode_e mixerMode);

src/main/flight/pid.c

@@ -445,7 +445,7 @@ void pidInitConfig(const pidProfile_t *pidProfile)
     horizonFactorRatio = (100 - pidProfile->horizon_tilt_effect) * 0.01f;
     maxVelocity[FD_ROLL] = maxVelocity[FD_PITCH] = pidProfile->rateAccelLimit * 100 * dT;
     maxVelocity[FD_YAW] = pidProfile->yawRateAccelLimit * 100 * dT;
-    const float ITermWindupPoint = (float)pidProfile->itermWindupPointPercent / 100.0f;
+    const float ITermWindupPoint = ((float)pidProfile->itermWindupPointPercent - 0.001f) / 100.0f;
     ITermWindupPointInv = 1.0f / (1.0f - ITermWindupPoint);
     itermAcceleratorGain = pidProfile->itermAcceleratorGain;
     crashTimeLimitUs = pidProfile->crash_time * 1000;
@@ -985,12 +985,7 @@ void FAST_CODE pidController(const pidProfile_t *pidProfile, const rollAndPitchT
         }
 
         // -----calculate I component
-        const float ITermNew = constrainf(ITerm + pidCoefficient[axis].Ki * itermErrorRate * dynCi, -itermLimit, itermLimit);
+        pidData[axis].I = constrainf(ITerm + pidCoefficient[axis].Ki * itermErrorRate * dynCi, -itermLimit, itermLimit);
-        const bool outputSaturated = mixerIsOutputSaturated(axis, errorRate);
-        if (outputSaturated == false || ABS(ITermNew) < ABS(ITerm)) {
-            // Only increase ITerm if output is not saturated
-            pidData[axis].I = ITermNew;
-        }
 
         // -----calculate D component
         if (pidCoefficient[axis].Kd > 0) {

src/main/interface/settings.c

@@ -846,7 +846,7 @@ const clivalue_t valueTable[] = {
     { "iterm_relax_type",           VAR_UINT8  | PROFILE_VALUE | MODE_LOOKUP, .config.lookup = { TABLE_ITERM_RELAX_TYPE }, PG_PID_PROFILE, offsetof(pidProfile_t, iterm_relax_type) },
     { "iterm_relax_cutoff",         VAR_UINT8  | PROFILE_VALUE, .config.minmax = { 1, 100 }, PG_PID_PROFILE, offsetof(pidProfile_t, iterm_relax_cutoff) },
 #endif
-    { "iterm_windup",               VAR_UINT8  | PROFILE_VALUE, .config.minmax = { 30, 99 }, PG_PID_PROFILE, offsetof(pidProfile_t, itermWindupPointPercent) },
+    { "iterm_windup",               VAR_UINT8  | PROFILE_VALUE, .config.minmax = { 30, 100 }, PG_PID_PROFILE, offsetof(pidProfile_t, itermWindupPointPercent) },
     { "iterm_limit",                VAR_UINT16 | PROFILE_VALUE, .config.minmax = { 0, 500 }, PG_PID_PROFILE, offsetof(pidProfile_t, itermLimit) },
     { "pidsum_limit",               VAR_UINT16 | PROFILE_VALUE, .config.minmax = { PIDSUM_LIMIT_MIN, PIDSUM_LIMIT_MAX }, PG_PID_PROFILE, offsetof(pidProfile_t, pidSumLimit) },
     { "pidsum_limit_yaw",           VAR_UINT16 | PROFILE_VALUE, .config.minmax = { PIDSUM_LIMIT_MIN, PIDSUM_LIMIT_MAX }, PG_PID_PROFILE, offsetof(pidProfile_t, pidSumLimitYaw) },

src/test/unit/pid_unittest.cc

@@ -67,7 +67,6 @@ extern "C" {
     float getThrottlePIDAttenuation(void) { return simulatedThrottlePIDAttenuation; }
     float getMotorMixRange(void) { return simulatedMotorMixRange; }
     float getSetpointRate(int axis) { return simulatedSetpointRate[axis]; }
-    bool mixerIsOutputSaturated(int, float) { return simulateMixerSaturated; }
     float getRcDeflectionAbs(int axis) { return ABS(simulatedRcDeflection[axis]); }
     void systemBeep(bool) { }
     bool gyroOverflowDetected(void) { return false; }
@@ -431,14 +430,41 @@ TEST(pidControllerTest, testMixerSaturation) {
     // Test full stick response
     setStickPosition(FD_ROLL, 1.0f);
     setStickPosition(FD_PITCH, -1.0f);
-    simulateMixerSaturated = true;
+    setStickPosition(FD_YAW, 1.0f);
+    simulatedMotorMixRange = 2.0f;
     pidController(pidProfile, &rollAndPitchTrims, currentTestTime());
 
     // Expect no iterm accumulation
-    EXPECT_FLOAT_EQ(0, pidData[FD_YAW].P);
     EXPECT_FLOAT_EQ(0, pidData[FD_ROLL].I);
     EXPECT_FLOAT_EQ(0, pidData[FD_PITCH].I);
     EXPECT_FLOAT_EQ(0, pidData[FD_YAW].I);
+
+    // Test itermWindup limit
+    // First store values without exceeding iterm windup limit
+    resetTest();
+    ENABLE_ARMING_FLAG(ARMED);
+    pidStabilisationState(PID_STABILISATION_ON);
+    setStickPosition(FD_ROLL, 0.1f);
+    setStickPosition(FD_PITCH, -0.1f);
+    setStickPosition(FD_YAW, 0.1f);
+    simulatedMotorMixRange = 0.0f;
+    pidController(pidProfile, &rollAndPitchTrims, currentTestTime());
+    float rollTestIterm = pidData[FD_ROLL].I;
+    float pitchTestIterm = pidData[FD_PITCH].I;
+    float yawTestIterm = pidData[FD_YAW].I;
+
+    // Now compare values when exceeding the limit
+    resetTest();
+    ENABLE_ARMING_FLAG(ARMED);
+    pidStabilisationState(PID_STABILISATION_ON);
+    setStickPosition(FD_ROLL, 0.1f);
+    setStickPosition(FD_PITCH, -0.1f);
+    setStickPosition(FD_YAW, 0.1f);
+    simulatedMotorMixRange = (pidProfile->itermWindupPointPercent + 1 / 100.0f);
+    pidController(pidProfile, &rollAndPitchTrims, currentTestTime());
+    ASSERT_NE(pidData[FD_ROLL].I, rollTestIterm);
+    ASSERT_NE(pidData[FD_PITCH].I, pitchTestIterm);
+    ASSERT_NE(pidData[FD_YAW].I, yawTestIterm);
 }
 
 // TODO - Add more scenarios