diff --git a/launch/step_4.launch.py b/launch/step_4.launch.py
index bee9cc5330bf8a8a731dc426299d0698b596e4a2..cfdde73e8cd5de93b64b1ad467a5f1ea1f15c439 100644
--- a/launch/step_4.launch.py
+++ b/launch/step_4.launch.py
@@ -15,5 +15,11 @@ def generate_launch_description():
             namespace='',
             executable='step_4',
             name='square'
+        ),
+        Node(
+            package='rqt_plot',
+            namespace='',
+            executable='rqt_plot',
+            name='rqt'
         )
     ])
diff --git a/lesson_05/step_4.py b/lesson_05/step_4.py
index 0aadceeac49995ffb174c923ca75f496161bf2eb..716649bbcdcd14af9bc112cbd0164a211b5106f8 100644
--- a/lesson_05/step_4.py
+++ b/lesson_05/step_4.py
@@ -13,12 +13,13 @@ def angle_diff(a1, a2):
 
 class RurMover(Node):
     def __init__(self):
-        super().__init__('minimal_publisher')
+        super().__init__('turtle_square_controller')
         self.publisher_twist = self.create_publisher(Twist, 'turtle1/cmd_vel', 10)
         self.pose_subscriber = self.create_subscription(Pose, 'turtle1/pose', self.pose_callback, 10)
         self.desired_heading = - math.pi / 2
         self.SIDE_TIME = 5.0
         self.LINEAR_SPEED = 0.5
+        self.Kp_angular = 4.0
         self.timer = self.create_timer(self.SIDE_TIME, self.pub_timer_callback)
 
     def pose_callback(self, msg):
@@ -27,12 +28,7 @@ class RurMover(Node):
         msg_pub = Twist()
         msg_pub.linear.x = self.LINEAR_SPEED
         error = angle_diff(self.desired_heading, msg.theta)
-        if error < 0:
-            msg_pub.angular.z = math.radians(90.0)
-            self.get_logger().info('Turn left')
-        else:
-            msg_pub.angular.z = math.radians(-90.0)
-            self.get_logger().info('Turn right')
+        msg_pub.angular.z = self.Kp_angular * error
         self.publisher_twist.publish(msg_pub)
 
     def pub_timer_callback(self):