diff --git a/safety_master_plugin/master_plugin.py b/safety_master_plugin/master_plugin.py
index 808ee68..f8c5835 100755
--- a/safety_master_plugin/master_plugin.py
+++ b/safety_master_plugin/master_plugin.py
@@ -1,5 +1,3 @@
-# from .ros_master_wrapper import ROSWrapper
-# from .qt_master_wrapper import QtWrapper
 from qt_gui.plugin import Plugin
 from python_qt_binding.QtCore import QTimer
 
diff --git a/safety_master_plugin/qt_master_wrapper.py b/safety_master_plugin/qt_master_wrapper.py
index fc8444d..a26fbe3 100644
--- a/safety_master_plugin/qt_master_wrapper.py
+++ b/safety_master_plugin/qt_master_wrapper.py
@@ -1,7 +1,5 @@
 #!/usr/bin/env python
 # coding=utf-8
-import os
-
 import math
 import datetime
 from ament_index_python.packages import get_package_share_directory
@@ -38,9 +36,9 @@ class QtWrapper:
             get_package_share_directory("safety_master_plugin")
         )
 
-        self.distance_pixmap = QPixmap("{0}/Distance.png".format(ui_directory_path))
-        self.angular_pixmap = QPixmap("{0}/Angular.png".format(ui_directory_path))
-        self.linear_pixmap = QPixmap("{0}/Linear.png".format(ui_directory_path))
+        self.distance_pixmap = QPixmap(f"{ui_directory_path}/Distance.png")
+        self.angular_pixmap = QPixmap(f"{ui_directory_path}/Angular.png")
+        self.linear_pixmap = QPixmap(f"{ui_directory_path}/Linear.png")
         self.widget.distanceImage.setPixmap(self.distance_pixmap)
         self.widget.angularImage.setPixmap(self.angular_pixmap)
         self.widget.linearImage.setPixmap(self.linear_pixmap)
@@ -150,7 +148,7 @@ class QtWrapper:
 
     def update_robot_info(self, robot_info):
         items_to_add = []
-        items_to_add.append(QStandardItem("pioneer{}".format(robot_info.robot_id)))
+        items_to_add.append(QStandardItem(f"pioneer{robot_info.robot_id}"))
         items_to_add.append(QStandardItem("{:.2f}".format(robot_info.battery_voltage)))
 
         if robot_info.state == SS.RUNNING:
@@ -184,7 +182,7 @@ class QtWrapper:
         )
 
         items_list = self.stdItemModel.findItems(
-            "pioneer{0}".format(robot_info.robot_id), Qt.MatchExactly
+            f"pioneer{robot_info.robot_id}", Qt.MatchExactly
         )
         if len(items_list) > 0:
             for item in items_list:
@@ -216,21 +214,19 @@ class QtWrapper:
             self.stdItemModel.setItem(self.stdItemModel.rowCount(), 0, new_robot_info)
 
             self.displayed_robots_id_list.append(robot_id)
-            self.log_info("pioneer{0} połączony".format(robot_id))
+            self.log_info(f"pioneer{robot_id} połączony")
         else:
             raise RuntimeError("Adding robot, which is already in master GUI")
 
     def remove_robot(self, robot_id):
-        items_list = self.stdItemModel.findItems(
-            "pioneer{0}".format(robot_id), Qt.MatchExactly
-        )
+        items_list = self.stdItemModel.findItems(f"pioneer{robot_id}", Qt.MatchExactly)
 
         if len(items_list) > 0:
             for item in items_list:
                 row_number = item.row()
                 self.stdItemModel.removeRow(row_number)
 
-        self.log_info("pioneer{0} rozłączony".format(robot_id))
+        self.log_info(f"pioneer{robot_id} rozłączony")
         self.displayed_robots_id_list.remove(robot_id)
 
     def log_info(self, info_text):
@@ -239,9 +235,8 @@ class QtWrapper:
         cursor = self.widget.logsBrowser.textCursor()
         cursor.movePosition(QTextCursor.End)
         self.widget.logsBrowser.setTextCursor(cursor)
-        # self.widget.logsBrowser.insertHtml('<font color="black">' + str(time) + '. ' + info_text + '</font><br>')
         self.widget.logsBrowser.insertHtml(
-            '<font color="black"> {0} {1}</font><br>'.format(time, info_text)
+            f'<font color="black"> {time} {info_text}</font><br>'
         )
         self.scroll_to_bottom()
 
diff --git a/safety_master_plugin/ros_master_wrapper.py b/safety_master_plugin/ros_master_wrapper.py
index 44dc13c..f3e6436 100644
--- a/safety_master_plugin/ros_master_wrapper.py
+++ b/safety_master_plugin/ros_master_wrapper.py
@@ -30,29 +30,40 @@ class ROSWrapper(Node):
         self.restrictions_publisher = None
 
         self.setup_subscribers_and_publishers()
+        self.subs = []
 
-        self._qos = QoSProfile(
+    def setup_subscribers_and_publishers(self):
+        publishers_qos = QoSProfile(
             reliability=QoSReliabilityPolicy.RELIABLE,
             durability=QoSDurabilityPolicy.TRANSIENT_LOCAL,
             history=QoSHistoryPolicy.SYSTEM_DEFAULT,
             liveliness=QoSLivelinessPolicy.AUTOMATIC,
             depth=10,
         )
-        self.subs = []
 
-    def setup_subscribers_and_publishers(self):
         self.master_stop_publisher = self.create_publisher(
-            Bool, "/pioneers/master_stop", 10
+            Bool, "/pioneers/master_stop", qos_profile=publishers_qos
         )
         self.restrictions_publisher = self.create_publisher(
-            RestrictionsMsg, "/pioneers/restrictions", 10
+            RestrictionsMsg, "/pioneers/restrictions", qos_profile=publishers_qos
         )
 
     def add_robot_subscriber(self, robot_id):
         if robot_id not in self.robot_info_subscribers:
             topic_name = "/pioneer{0}/robot_info".format(robot_id)
+            subscription_qos = QoSProfile(
+                reliability=QoSReliabilityPolicy.RELIABLE,
+                durability=QoSDurabilityPolicy.VOLATILE,
+                history=QoSHistoryPolicy.SYSTEM_DEFAULT,
+                liveliness=QoSLivelinessPolicy.AUTOMATIC,
+                depth=10,
+            )
+
             self.robot_info_subscribers[robot_id] = self.create_subscription(
-                RobotInfoMsg, topic_name, self.handle_robot_info_update, 10
+                RobotInfoMsg,
+                topic_name,
+                self.handle_robot_info_update,
+                qos_profile=subscription_qos,
             )
         else:
             raise RuntimeError(
@@ -72,11 +83,11 @@ class ROSWrapper(Node):
 
     def unsubscribe(self, subscriber):
         if subscriber is not None:
-            subscriber.destroy()
+            self.destroy_subscription(subscriber)
 
     def unregister_publisher(self, publisher):
         if publisher is not None:
-            publisher.destroy()
+            self.destroy_publisher(publisher)
 
     def publish_periodic_update(self):
         restrictions = self.get_restrictions()
@@ -123,7 +134,7 @@ class ROSWrapper(Node):
         robots_id_list = []
 
         # Można to zrobić lepiej np. czekać na publikowaną wiadomość na robot_info
-        for pioneer_id in range(6):
+        for pioneer_id in range(1, 7):
             published_topics_list = []
             try:
                 published_topics_list = self.get_publisher_names_and_types_by_node(