WiP Thermal rewrite

1 files changed, 45 insertions, 22 deletions

diff --git a/source/Core/Threads/PIDThread.cpp b/source/Core/Threads/PIDThread.cpp
index 83c53efd..4927bb47 100644
--- a/source/Core/Threads/PIDThread.cpp
+++ b/source/Core/Threads/PIDThread.cpp
@@ -30,7 +30,7 @@ int32_t                    powerSupplyWattageLimit = 0;
 bool                       heaterThermalRunaway    = false;

 

 static int32_t getPIDResultX10Watts(TemperatureType_t set_point, TemperatureType_t current_value);

-static void    detectThermalRunaway(const TemperatureType_t currentTipTempInC, const TemperatureType_t tError);

+static void detectThermalRunaway(const TemperatureType_t currentTipTempInC, const uint32_t x10WattsOut) ;

 static void    setOutputx10WattsViaFilters(int32_t x10Watts);

 static int32_t getX10WattageLimits();

 

@@ -92,8 +92,8 @@ void startPIDTask(void const *argument __unused) {
           PIDTempTarget = TipThermoModel::getTipMaxInC();

         }

 

-        detectThermalRunaway(currentTipTempInC, PIDTempTarget - currentTipTempInC);

         x10WattsOut = getPIDResultX10Watts(PIDTempTarget, currentTipTempInC);

+        detectThermalRunaway(currentTipTempInC,x10WattsOut);

       } else {

         detectThermalRunaway(currentTipTempInC, 0);

       }

@@ -228,31 +228,54 @@ int32_t getPIDResultX10Watts(TemperatureType_t set_point, TemperatureType_t curr
 #endif

 }

 

-void detectThermalRunaway(const TemperatureType_t currentTipTempInC, const TemperatureType_t tError) {

-  static TemperatureType_t tipTempCRunawayTemp   = 0;

-  static TickType_t        runawaylastChangeTime = 0;

+/*

+ * Detection of thermal runaway

+ * The goal of this is to handle cases where something has gone wrong

+ * 1. The tip MOSFET is broken, so power is being constantly applied to the tip

+ * a. This can show as temp being stuck at max

+ * b. Or temp rising when the heater is off

+ * 2. Broken temperature sense

+ * a. Temp is stuck at a value

+ * These boil down to either a constantly rising temperature or a temperature that is stuck at a value

+ * These are both covered; but looking at the eye/delta between min and max temp seen

+ */

+void detectThermalRunaway(const TemperatureType_t currentTipTempInC, const uint32_t x10WattsOut) {

 

-  // Check for thermal runaway, where it has been x seconds with negligible (y) temp rise

-  // While trying to actively heat

+  static TemperatureType_t tiptempMin         = 0xFFFF; // Min tip temp seen

+  static TemperatureType_t tipTempMax         = 0;      // Max tip temp seen while heater is on

+  bool                     thisCycleIsHeating = x10WattsOut > 0;

+  static TickType_t        heatCycleStart     = 0;

 

-  // If we are more than 20C below the setpoint

-  if ((tError > THERMAL_RUNAWAY_TEMP_C)) {

+  static bool haveSeenDelta = false;

 

-    // If we have heated up by more than 20C since last sample point, snapshot time and tip temp

-    TemperatureType_t delta = currentTipTempInC - tipTempCRunawayTemp;

-    if (delta > THERMAL_RUNAWAY_TEMP_C) {

-      // We have heated up more than the threshold, reset the timer

-      tipTempCRunawayTemp   = currentTipTempInC;

-      runawaylastChangeTime = xTaskGetTickCount();

-    } else {

-      if ((xTaskGetTickCount() - runawaylastChangeTime) > (THERMAL_RUNAWAY_TIME_SEC * TICKS_SECOND)) {

-        // It has taken too long to rise

+  if (haveSeenDelta) {

+    return;

+  }

+

+  if (currentTipTempInC < tiptempMin) {

+    tiptempMin = currentTipTempInC;

+  }

+  if (thisCycleIsHeating && currentTipTempInC > tipTempMax) {

+    tipTempMax = currentTipTempInC;

+  }

+  if (thisCycleIsHeating) {

+    if (heatCycleStart == 0) {

+      heatCycleStart = xTaskGetTickCount();

+    }

+  } else {

+    heatCycleStart = 0;

+  }

+

+  if ((xTaskGetTickCount() - heatCycleStart) > (THERMAL_RUNAWAY_TIME_SEC * TICKS_SECOND)) {

+    if (tipTempMax > tiptempMin) {

+      // Have been heating for min seconds, check if the delta is large enough

+      TemperatureType_t delta = tipTempMax - tiptempMin;

+      haveSeenDelta           = true;

+

+      if (delta < THERMAL_RUNAWAY_TEMP_C) {

         heaterThermalRunaway = true;

       }

     }

-  } else {

-    tipTempCRunawayTemp   = currentTipTempInC;

-    runawaylastChangeTime = xTaskGetTickCount();

   }

 }

 

@@ -308,4 +331,4 @@ void setOutputx10WattsViaFilters(int32_t x10WattsOut) {
 #endif

   setTipX10Watts(x10WattsOut);

   resetWatchdog();

-}
\ No newline at end of file
+}