autotest: add autotest for tuning loiter x/y speed

Tools/autotest/arducopter.py

@@ -404,7 +404,7 @@ def RecordThenPlayMission(self, side=50, timeout=300):
     def do_RTL(self, distance_min=None, check_alt=True, distance_max=10, timeout=250, quiet=False):
         """Enter RTL mode and wait for the vehicle to disarm at Home."""
         self.change_mode("RTL")
-        self.hover()
+        self.set_rc_default()
         self.wait_rtl_complete(check_alt=check_alt, distance_max=distance_max, timeout=timeout, quiet=True)
 
     def wait_rtl_complete(self, check_alt=True, distance_max=10, timeout=250, quiet=False):
@@ -11802,6 +11802,34 @@ def Ch6TuningWPSpeed(self):
 
         self.do_RTL()
 
+    def Ch6TuningLoitMaxXYSpeed(self):
+        '''test loiter can be changed via Ch6 tuning knob'''
+        self.set_parameters({
+            "RC6_OPTION": 219,  # RC6 used for tuning
+            "TUNE": 60,  # 60 is x/y loiter speed
+            "TUNE_MIN": 0.02,  # 20cm/s
+            "TUNE_MAX": 1000,  # 10m/s
+            "AUTO_OPTIONS": 3,
+        })
+        self.set_rc(6, 2000)
+
+        self.takeoff(mode='LOITER')
+
+        self.set_rc(2, 1000)
+
+        self.wait_groundspeed(9.5, 10.5, minimum_duration=5)
+
+        self.set_rc(6, 1500)
+        self.wait_groundspeed(4.5, 5.5, minimum_duration=5)
+
+        self.set_rc(6, 2000)
+        self.wait_groundspeed(9.5, 10.5, minimum_duration=5)
+
+        self.set_rc(6, 1300)
+        self.wait_groundspeed(2.5, 3.5, minimum_duration=5)
+
+        self.do_RTL()
+
     def PILOT_THR_BHV(self):
         '''test the PILOT_THR_BHV parameter'''
         self.start_subtest("Test default behaviour, no disarm on land")
@@ -12695,6 +12723,7 @@ def tests2b(self):  # this block currently around 9.5mins here
             self.TestTetherStuck,
             self.ScriptingFlipMode,
             self.CompassLearnCopyFromEKF,
+            self.Ch6TuningLoitMaxXYSpeed,
         ])
         return ret