autotest: add test for stuck tether simulation

Tools/autotest/arducopter.py

@@ -8304,6 +8304,57 @@ def WatchAlts(self):
 
         self.do_RTL()
 
+    def TestTetherStuck(self):
+        """Test tethered vehicle stuck because of tether"""
+        # Enable tether simulation
+        self.set_parameters({
+            "SIM_TETH_ENABLE": 1,
+        })
+        self.delay_sim_time(2)
+        self.reboot_sitl()
+
+        # Set tether line length
+        self.set_parameters({
+            "SIM_TETH_LINELEN": 10,
+        })
+        self.delay_sim_time(2)
+
+        # Prepare and take off
+        self.wait_ready_to_arm()
+        self.arm_vehicle()
+        self.takeoff(10, mode='LOITER')
+
+        # Simulate vehicle getting stuck by increasing RC throttle
+        self.set_rc(3, 1900)
+        self.delay_sim_time(5, reason='let tether get stuck')
+
+        # Monitor behavior for 10 seconds
+        tstart = self.get_sim_time()
+        initial_alt = self.get_altitude()
+        stuck = True  # Assume it's stuck unless proven otherwise
+
+        while self.get_sim_time() - tstart < 10:
+            # Fetch current altitude
+            current_alt = self.get_altitude()
+            self.progress(f"current_alt={current_alt}")
+
+            # Fetch and log battery status
+            battery_status = self.mav.recv_match(type='BATTERY_STATUS', blocking=True, timeout=1)
+            if battery_status:
+                self.progress(f"Battery: {battery_status}")
+
+            # Check if the vehicle is stuck.
+            # We assume the vehicle is stuck if the current is high and the altitude is not changing
+            if battery_status and (battery_status.current_battery < 6500 or abs(current_alt - initial_alt) > 2):
+                stuck = False  # Vehicle moved or current is abnormal
+                break
+
+        if not stuck:
+            raise NotAchievedException("Vehicle did not get stuck as expected")
+
+        # Land and disarm the vehicle to ensure we can go down
+        self.land_and_disarm()
+
     def fly_rangefinder_drivers_fly(self, rangefinders):
         '''ensure rangefinder gives height-above-ground'''
         self.change_mode('GUIDED')
@@ -12330,6 +12381,7 @@ def tests2b(self):  # this block currently around 9.5mins here
             self.MAV_CMD_MISSION_START_p1_p2,
             self.ScriptingAHRSSource,
             self.CommonOrigin,
+            self.TestTetherStuck,
         ])
         return ret