GAZEBO RUNNING (#249)

Nafis and Nico:
* loaded into gazebo

uwrt_mars_rover_drivetrain/uwrt_mars_rover_drivetrain_description/config/physical_parameters.yaml

@@ -2,6 +2,7 @@ chassis:
   length: 1.17
   width: 0.807
   height: 0.2
+  mass: 20 #assuming 20kg 
 
 wheels:
   # Should match values defined in uwrt_mars_rover_drivetrain_hw/config/drivetrain_controllers.yaml

uwrt_mars_rover_drivetrain/uwrt_mars_rover_drivetrain_description/launch/gazebo.launch.py

@@ -0,0 +1,56 @@
+import os
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import IncludeLaunchDescription
+from launch.launch_description_sources import PythonLaunchDescriptionSource
+
+
+from launch_ros.actions import Node
+import xacro
+
+
+def generate_launch_description():
+
+    # Specify the name of the package and path to xacro file within the package
+    pkg_name = 'uwrt_mars_rover_drivetrain_description'
+    file_subpath = 'urdf/drivetrain.urdf.xacro'
+
+
+    # Use xacro to process the file
+    xacro_file = os.path.join(get_package_share_directory(pkg_name),file_subpath)
+    robot_description_raw = xacro.process_file(xacro_file).toxml()
+
+
+    # Configure the node
+    node_robot_state_publisher = Node(
+        package='robot_state_publisher',
+        executable='robot_state_publisher',
+        output='screen',
+        parameters=[{'robot_description': robot_description_raw,
+        'use_sim_time': True}] # add other parameters here if required
+    )
+
+
+
+    gazebo = IncludeLaunchDescription(
+        PythonLaunchDescriptionSource([os.path.join(
+            get_package_share_directory('gazebo_ros'), 'launch'), '/gazebo.launch.py']),
+        )
+
+
+    spawn_entity = Node(package='gazebo_ros', executable='spawn_entity.py',
+                    arguments=['-topic', 'robot_description',
+                                '-entity', 'my_bot'],
+                    output='screen')
+
+
+
+
+
+
+    # Run the node
+    return LaunchDescription([
+        gazebo,
+        node_robot_state_publisher,
+        spawn_entity
+    ])

uwrt_mars_rover_drivetrain/uwrt_mars_rover_drivetrain_description/urdf/drivetrain.macro.xacro

@@ -13,11 +13,18 @@
     <xacro:property name="chassis_length" value="${chassis_parameters['length']}" scope="parent"/>
     <xacro:property name="chassis_width" value="${chassis_parameters['width']}" scope="parent"/>
     <xacro:property name="chassis_height" value="${chassis_parameters['height']}" scope="parent"/>
+    <xacro:property name="chassis_mass" value="${chassis_parameters['mass']}" scope="parent"/>
+
+
 
     <!-- wheel parameters -->
     <xacro:property name="wheel_diameter" value="${wheel_parameters['diameter']}" scope="parent"/>
     <xacro:property name="wheel_width" value="${wheel_parameters['width']}" scope="parent"/>
     <xacro:property name="wheel_mass" value="${wheel_parameters['mass']}" scope="parent"/>
+    <xacro:property name="wheel_radius" value="${(wheel_parameters['diameter'])/2}" scope="parent"/>
+
+
+
 
     <!-- control parameters -->
     <xacro:property name="mechanical_reduction" value="${control_parameters['mechanical_reduction']}" scope="parent"/>
@@ -34,6 +41,26 @@
     </inertial>
   </xacro:macro>
 
+   <xacro:macro name="chassis_inertia" params="chassis_width:=^ chassis_height:=^ chassis_length:=^ chassis_mass:=^">
+    <inertial>
+      <mass value="${chassis_mass}" />
+      <inertia
+          ixx="${(1/12)*(((chassis_height)*(chassis_height))+((chassis_width)*(chassis_width)))}" ixy="0.0" ixz="0.0"
+          iyy="${(1/12)*(((chassis_height)*(chassis_height))+((chassis_length)*(chassis_length)))}" iyz="0.0"
+          izz="${(1/12)*(((chassis_width)*(chassis_width))+((chassis_length)*(chassis_length)))}"/>
+    </inertial>
+  </xacro:macro>
+
+  <xacro:macro name="wheel_intertia" params="wheel_radius:=^ wheel_width:=^ wheel_mass:=^">
+    <inertial>
+      <mass value="${wheel_mass}" />
+      <inertia
+          ixx="${(1/12)*(3*((wheel_radius)*(wheel_radius))+((wheel_width)*(wheel_width)))}" ixy="0.0" ixz="0.0"
+          iyy="${(1/12)*(3*((wheel_radius)*(wheel_radius))+((wheel_width)*(wheel_width)))}" iyz="0.0"
+          izz="${(1/2)*((wheel_radius)*(wheel_radius))}"/>
+    </inertial>
+  </xacro:macro>
+
   <xacro:macro name="identical_visual_collision" params="**identical_blocks">
     <visual>
       <xacro:insert_block name="identical_blocks"/>
@@ -60,7 +87,7 @@
           </geometry>
         </idential_blocks>
       </xacro:identical_visual_collision>
-      <xacro:default_inertial mass="${wheel_mass}"/>
+      <xacro:wheel_intertia />
     </link>
   </xacro:macro>
 

uwrt_mars_rover_drivetrain/uwrt_mars_rover_drivetrain_description/urdf/drivetrain.urdf.xacro

@@ -29,7 +29,7 @@
         </geometry>
       </identical_blocks>
     </xacro:identical_visual_collision>
-    <xacro:default_inertial/>
+    <xacro:chassis_inertia/>
   </link>
 
   <!-- wheels -->