Clear inverse kinematics node code

ros2_ws/src/iiwa/iiwa_inverse_kinematics/iiwa_inverse_kinematics/inverse_kinematics_node.py

 import os
-import re
 
 import rclpy
 from rclpy.node import Node
@@ -21,6 +20,7 @@ class InverseKinematicsNode(Node):
             10)
         self.publisher = self.create_publisher(JointTrajectory, '/iiwa_arm_controller/joint_trajectory', 10)
 
+        # load KUKA URDF
         urdf_file_path = os.path.join(
             get_package_share_directory('iiwa_description'), 'urdf', 'iiwa14.urdf')
         self.get_logger().info(f'Loading URDF from: {urdf_file_path}')
@@ -35,7 +35,7 @@ class InverseKinematicsNode(Node):
         self.joint_names = [f'joint_a{i+1}' for i in range(len(self.Slist[0]))]
 
         self.joint_angles = np.zeros(len(self.Slist[0]))
-
+        # forward kinematics
         T = FKinBody(self.M, self.Blist, self.joint_angles)
         rotation_matrix = T[:3, :3]
         quat = Rotation.from_matrix(rotation_matrix).as_quat()