diff --git a/route_guidance_ros/scripts/VirtualNavigation.py b/route_guidance_ros/scripts/VirtualNavigation.py
index b307260ca68f71deee1ff89ae1bd1213398f7bb0..9b1ddc7437df247e3678742d248ed11fc16ca8c5 100755
--- a/route_guidance_ros/scripts/VirtualNavigation.py
+++ b/route_guidance_ros/scripts/VirtualNavigation.py
@@ -107,7 +107,7 @@ class VirtualNavigation(Event, Command, Query):
         self.latest_target_robot = None
 
     def position_to_coord(self, position):
-        if isinstance(position, str) and position in self.pointname_coord_table:
+        if isinstance(position, str):
             return self.pointname_coord_table[position]
         else:
             return position
@@ -116,7 +116,10 @@ class VirtualNavigation(Event, Command, Query):
         # ERRORなロボットは初期位置に戻す
         self.back_stucked_robots_to_init_pos()
 
-        target_coord = self.position_to_coord(target_position)
+        try:
+            target_coord = self.position_to_coord(target_position)
+        except KeyError:
+            return RoIS_HRI.ReturnCode_t.BAD_PARAMETER.value
         if self.mode == Mode.NaviToUser:
             # READYなロボットの中でゴールに最も近い位置にいるものにNavigationさせる
             target_robot = self._component.get_nearest_robotname(target_coord, self.nav_state_table)
diff --git a/route_guidance_ros/scripts/service_app_lv2.py b/route_guidance_ros/scripts/service_app_lv2.py
index d652de29cf8070741e76c2be2ceea98c0a7f5f6c..9ba746aba24e3d5dc10e91552c9a33da6e63f55d 100644
--- a/route_guidance_ros/scripts/service_app_lv2.py
+++ b/route_guidance_ros/scripts/service_app_lv2.py
@@ -35,7 +35,7 @@ class Service(Service_Application_IF):
             {'trigger': 'Succeeded', 'source': Task.NaviToGuide, 'dest': Task.NaviToUser,  'after': 'start_navi_to_user'        },
         ]
         self.target_pos = "point_c"
-        self.machine = Machine(self, states=states, transitions=transitions, initial=Task.Init, send_event=True)
+        self.machine = Machine(self, states=states, transitions=transitions, initial=Task.Init)
         self.latest_event_id_table = {}
 
     def completed(self, command_id, completed_status):
@@ -44,7 +44,7 @@ class Service(Service_Application_IF):
         if completed_status == Completed_Status.OK:
             self.Succeeded()
         elif completed_status == Completed_Status.ABORT:
-            self.Failed(self.target_pos)
+            self.Failed()
 
     def notify_error(self, error_id, error_type):
         print('received error event {}({}) '.format( \
@@ -56,32 +56,38 @@ class Service(Service_Application_IF):
             print(colored("speech recognized successfully.", 'green'))
             self.Succeeded()
 
-    def start_navi_to_user(self, event):
+    def start_navi_to_user(self):
         dest = self.target_pos
         print(colored("NaviToUser started.", 'cyan'))
         (return_code, command_id) = self._proxy.set_parameter('Navigation', dest, "", "")
         stautus = RoIS_HRI.ReturnCode_t(return_code)
 
-    def listen_destination(self, event):
+    def listen_destination(self):
         print(colored("ListenDest started.", 'cyan'))
 
-    def start_navi_to_guide(self, event):
+    def start_navi_to_guide(self):
         sr_event_id = self.latest_event_id_table['speech_recognized']
         status, results = self._proxy.get_event_detail(sr_event_id, "")
         dest = results[1][0]
         print("dest is ", dest)
-        print(colored("NaviToGuide started.", 'cyan'))
         (return_code, command_id) = self._proxy.set_parameter('Navigation', dest, "", "")
-        stautus = RoIS_HRI.ReturnCode_t(return_code)
+        status = RoIS_HRI.ReturnCode_t(return_code)
+        if status == RoIS_HRI.ReturnCode_t.BAD_PARAMETER:
+            print(colored("Bad destination detected.", 'yellow'))
+            print(colored("Trying to ask again...", 'yellow'))
+            self.state = Task.ListenDest
+            self.listen_destination()
+        else:
+            print(colored("NaviToGuide started.", 'cyan'))
 
-    def end_service(self, event):
+    def end_service(self):
         print(colored("Route Guidance Completed !", 'cyan'))
 
     def run(self):
         self._proxy = xmlrpc.client.ServerProxy(self._uri)
         time.sleep(3)
         return_code, subscribe_id = self._proxy.subscribe('speech_recognized', "")
-        self.Start(self.target_pos)
+        self.Start()
 
 
 if __name__ == '__main__':