autotest: Added airspeedless takeoff test with stock parameters

Tools/autotest/arduplane.py

@@ -4714,6 +4714,46 @@ class AutoTestPlane(vehicle_test_suite.TestSuite):
 
         self.fly_home_land_and_disarm()
 
+    def TakeoffTakeoff4(self):
+        '''Test the behaviour of a takeoff in TAKEOFF mode, pt4.
+
+        This is the same as case #3, but with almost stock parameters and without a catapult.
+
+        Conditions:
+        - ARSPD_USE=0
+        '''
+
+        self.customise_SITL_commandline(
+            [],
+            model='plane-catapult',
+            defaults_filepath=self.model_defaults_filepath("plane")
+        )
+        self.set_parameters({
+            "ARSPD_USE": 0.0,
+        })
+        self.change_mode("TAKEOFF")
+
+        self.wait_ready_to_arm()
+        self.arm_vehicle()
+
+        # Check whether we're at max throttle below TKOFF_LVL_ALT.
+        test_alt = self.get_parameter("TKOFF_LVL_ALT")-10
+        self.wait_altitude(test_alt, test_alt+2, relative=True)
+        self.assert_servo_channel_value(3, 1000+10*(self.get_parameter("THR_MAX")), operator.le)
+        self.assert_servo_channel_value(3, 1000+10*(self.get_parameter("THR_MAX"))-10, operator.ge)
+
+        # Check whether we're still at max throttle past TKOFF_LVL_ALT.
+        test_alt = self.get_parameter("TKOFF_LVL_ALT")+10
+        self.wait_altitude(test_alt, test_alt+2, relative=True)
+        self.assert_servo_channel_value(3, 1000+10*(self.get_parameter("THR_MAX")), operator.le)
+        self.assert_servo_channel_value(3, 1000+10*(self.get_parameter("THR_MAX"))-10, operator.ge)
+
+        # Wait for the takeoff to complete.
+        target_alt = self.get_parameter("TKOFF_ALT")
+        self.wait_altitude(target_alt-5, target_alt, relative=True)
+
+        self.fly_home_land_and_disarm()
+
     def DCMFallback(self):
         '''Really annoy the EKF and force fallback'''
         self.reboot_sitl()
@@ -6060,6 +6100,7 @@ class AutoTestPlane(vehicle_test_suite.TestSuite):
             self.TakeoffTakeoff1,
             self.TakeoffTakeoff2,
             self.TakeoffTakeoff3,
+            self.TakeoffTakeoff4,
             self.ForcedDCM,
             self.DCMFallback,
             self.MAVFTP,