diff --git a/waypoint_nav/scripts/tandem_run_manager.py b/waypoint_nav/scripts/tandem_run_manager.py
index 85cbf06..c402e00 100755
--- a/waypoint_nav/scripts/tandem_run_manager.py
+++ b/waypoint_nav/scripts/tandem_run_manager.py
@@ -36,9 +36,10 @@
         self.costmap_client1 = dynamic_reconfigure.client.Client("/move_base/global_costmap/obstacle_layer1")
         self.costmap_client2 = dynamic_reconfigure.client.Client("/move_base/global_costmap/obstacle_layer2")
         ## Variable
+        self.front_angle = 40 # degree
+        self.danger_dist = 1.0 # meter
         self.waypoint_num = 0
         self.front_range = None
-        self.danger_dist = 1.0
         self.in_tandem_area = False
         self.stop = False
         return
@@ -70,15 +71,17 @@
         try:
             if self.front_range is None:
                 front = round(-msg.angle_min / msg.angle_increment)
-                ran = int(round(np.deg2rad(20) / msg.angle_increment))
+                ran = int(round(np.deg2rad(self.front_angle/2) / msg.angle_increment))
                 self.front_range = [front-ran, front+ran]
                 return
             
             if not self.in_tandem_area: return
             ranges = np.array(msg.ranges[self.front_range[0]:self.front_range[1]])
+            ## Use simply minimum
             ranges[ranges <= msg.range_min] = msg.range_max
             min_range = min(ranges)
-            #sort_ranges = np.sort(msg.ranges[self.front_range[0]:self.front_range[1]])
+            ## or use sort
+            #sort_ranges = np.sort(ranges)
             #min_range = np.mean(sort_ranges[:5])
             if (not self.stop) and (min_range < self.danger_dist):
                 self.stop_nav()