Param for Max Retrial of Engine Cranking.

Tools/autotest/quadplane.py

@@ -1116,6 +1116,53 @@ def ICEngine(self):
         self.change_mode('FBWA')
         self.wait_servo_channel_value(3, 2000)
 
+        self.start_subtest("Testing automatic restart")
+        # Limit start attempts to 4
+        max_tries = 4
+        self.set_parameter("ICE_STRT_MX_RTRY", max_tries)
+        # Make the engine unable to run (by messing up the RPM sensor)
+        rpm_chan = self.get_parameter("ICE_RPM_CHAN")
+        self.set_parameter("ICE_RPM_CHAN", 120) # Set to a non-existent sensor
+        self.set_rc(rc_engine_start_chan, 2000)
+        self.wait_statustext("Uncommanded engine stop")
+        self.wait_statustext("Starting engine")
+        # Restore the engine
+        self.set_parameter("ICE_RPM_CHAN", rpm_chan)
+        # Make sure the engine continues to run for the next 30 seconds
+        try:
+            self.wait_statustext("Uncommanded engine stop", timeout=30)
+            # The desired result is for the wait_statustext raise AutoTestTimeoutException
+            raise NotAchievedException("Engine stopped unexpectedly")
+        except AutoTestTimeoutException:
+            pass
+        self.context_stop_collecting("STATUSTEXT")
+
+        self.start_subtest("Testing automatic starter attempt limit")
+        # Try this test twice.
+        # For the first run, since the engine has been running successfully in
+        # the previous test for 30 seconds, the limit should reset. For the
+        # second run, after commanding an engine stop, the limit should reset.
+        for i in range(2):
+            self.context_collect("STATUSTEXT")
+            self.set_parameter("ICE_RPM_CHAN", 120) # Set to a non-existent sensor
+            self.set_rc(rc_engine_start_chan, 2000)
+            self.wait_statustext("Engine max crank attempts reached", check_context=True, timeout=30)
+            self.delay_sim_time(30) # wait for another 30 seconds to make sure the engine doesn't restart
+            messages = self.context_get().collections["STATUSTEXT"]
+            self.context_stop_collecting("STATUSTEXT")
+            # check for the exact number of starter attempts
+            attempts = 0
+            for m in messages:
+                if "Starting engine" == m.text:
+                    attempts += 1
+            if attempts != max_tries:
+                raise NotAchievedException(f"Run {i+1}: Expected {max_tries} attempts, got {attempts}")
+            # Command an engine stop
+            self.context_collect("STATUSTEXT")
+            self.set_rc(rc_engine_start_chan, 1000)
+            self.wait_statustext("ignition:0", check_context=True)
+            self.context_stop_collecting("STATUSTEXT")
+
     def ICEngineMission(self):
         '''Test ICE Engine Mission support'''
         rc_engine_start_chan = 11

libraries/AP_ICEngine/AP_ICEngine.cpp

@@ -181,6 +181,13 @@ const AP_Param::GroupInfo AP_ICEngine::var_info[] = {
     // This allows one time conversion while allowing user to flash between versions with and without converted params
     AP_GROUPINFO_FLAGS("FMT_VER", 19, AP_ICEngine, param_format_version, 0, AP_PARAM_FLAG_HIDDEN),
 
+    // @Param: STRT_MX_RTRY
+    // @DisplayName: Maximum number of retries
+    // @Description: If set 0 then there is no limit to retrials. If set to a value greater than 0 then the engine will retry starting the engine this many times before giving up.
+    // @User: Standard
+    // @Range: 0 127
+    AP_GROUPINFO("STRT_MX_RTRY", 20, AP_ICEngine, max_crank_retry, 0),
+
     AP_GROUPEND
 };
 
@@ -379,6 +386,10 @@ void AP_ICEngine::update(void)
         if (should_run) {
             state = ICE_START_DELAY;
         }
+        crank_retry_ct = 0;
+        // clear the last uncommanded stop time, we only care about tracking
+        // the last one since the engine was started
+        last_uncommanded_stop_ms = 0;
         break;
 
     case ICE_START_HEIGHT_DELAY: {
@@ -402,8 +413,16 @@ void AP_ICEngine::update(void)
         if (!should_run) {
             state = ICE_OFF;
         } else if (now - starter_last_run_ms >= starter_delay*1000) {
-            GCS_SEND_TEXT(MAV_SEVERITY_INFO, "Starting engine");
-            state = ICE_STARTING;
+            // check if we should retry starting the engine
+            if (max_crank_retry <= 0 || crank_retry_ct < max_crank_retry) {
+                GCS_SEND_TEXT(MAV_SEVERITY_INFO, "Starting engine");
+                state = ICE_STARTING;
+                crank_retry_ct++;
+            } else {
+                GCS_SEND_TEXT(MAV_SEVERITY_CRITICAL, "Engine max crank attempts reached");
+                // Mark the last run now so we don't send this message every loop
+                starter_last_run_ms = now;
+            }
         }
         break;
 
@@ -429,7 +448,14 @@ void AP_ICEngine::update(void)
                 rpm_value < rpm_threshold) {
                 // engine has stopped when it should be running
                 state = ICE_START_DELAY;
-                GCS_SEND_TEXT(MAV_SEVERITY_INFO, "Uncommanded engine stop");
+                GCS_SEND_TEXT(MAV_SEVERITY_CRITICAL, "Uncommanded engine stop");
+                if (last_uncommanded_stop_ms != 0 &&
+                        now - last_uncommanded_stop_ms > 3*(starter_time + starter_delay)*1000) {
+                    // if it has been a long enough time since the last uncommanded stop
+                    // (3 times the time between start attempts) then reset the retry count
+                    crank_retry_ct = 0;
+                }
+                last_uncommanded_stop_ms = now;
             }
         }
 #endif

libraries/AP_ICEngine/AP_ICEngine.h

@@ -107,6 +107,10 @@ class AP_ICEngine {
     // delay between start attempts (seconds)
     AP_Float starter_delay;
 
+    // max crank retry
+    AP_Int8 max_crank_retry;
+    int8_t crank_retry_ct;
+
 #if AP_RPM_ENABLED
     // RPM above which engine is considered to be running
     AP_Int32 rpm_threshold;
@@ -118,6 +122,9 @@ class AP_ICEngine {
     // time when we last ran the starter
     uint32_t starter_last_run_ms;
 
+    // time when we last had an uncommanded engine stop
+    uint32_t last_uncommanded_stop_ms;
+
     // throttle percentage for engine start
     AP_Int8 start_percent;