Fix RViz file of simple_robot

ros2_ws/src/simple_robot_1dof/urdf/simple_robot.urdf

 <?xml version="1.0"?>
-<robot name="simple_robot" xmlns:xacro="http://www.ros.org/wiki/xacro">
+<robot name="simple_robot">
 
-  <link name="map">
-    <origin rpy="0 0 0" xyz="0 0 0" />
-    <visual>
-      <geometry>
-        <box size="0.1 0.1 0.1"/>
-      </geometry>
-      <material name="grey">
-        <color rgba="0.5 0.5 0.5 1"/>
-      </material>
-    </visual>
-  </link>
+  <link name="map" />
 
   <link name="arm1">
     <visual>
@@ -23,6 +13,11 @@
         <color rgba="1.0 0.0 0.0 1"/>
       </material>
     </visual>
+    <inertial>
+      <origin xyz="0 0 0.355" rpy="0 0 0"/>
+      <mass value="5"/>
+      <inertia ixx="0.05" ixy="0" ixz="0" iyy="0.05" iyz="0" izz="0.05"/>
+    </inertial>
   </link>
 
   <joint name="joint1" type="revolute">
@@ -43,13 +38,18 @@
         <color rgba="0.0 1.0 0.0 1"/>
       </material>
     </visual>
+    <inertial>
+      <mass value="5"/>
+      <inertia ixx="0.05" ixy="0" ixz="0" iyy="0.05" iyz="0" izz="0.05"/>
+      <origin xyz="-0.15 0 0" rpy="0 -1.5707 0"/>
+    </inertial>
   </link>
 
   <joint name="joint2" type="revolute">
     <parent link="arm1"/>
     <child link="arm2"/>
     <origin xyz="0 0 0.71"/>
-    <axis xyz="1 0 0"/>
+    <axis xyz="0 1 0"/>
     <limit effort = "300" lower="-2.96705972839" upper="2.96705972839" velocity = "10" />
   </joint>
 
@@ -63,13 +63,18 @@
         <color rgba="0.0 0.0 1.0 1"/>
       </material>
     </visual>
+    <inertial>
+      <mass value="5"/>
+      <inertia ixx="0.05" ixy="0" ixz="0" iyy="0.05" iyz="0" izz="0.05"/>
+      <origin xyz="-0.15 0 0" rpy="0 -1.5707 0"/>
+    </inertial>
   </link>
 
   <joint name="joint3" type="revolute">
     <parent link="arm2"/>
     <child link="arm3"/>
     <origin xyz="-0.3 0 0"/>
-    <axis xyz="1 0 0"/>
+    <axis xyz="0 1 0"/>
     <limit effort = "300" lower="-2.96705972839" upper="2.96705972839" velocity = "10" />
   </joint>