Attaching a sensor to a PARTICULAR LINK of an animated actor

edit

Hello, that's my first question here.

I'm currently having a really hard time trying to find out a way to connect an IMU sensor to a certain link of an animated actor. I've been experimenting a lot and now I'm posting my last piece of code below. I ended up with IMU as a big cube (just for better visualization) attached to actor's body but not to the link I wanted (RightLeg), check out the picture.

The IMU link does not appear on the Gazebo links list in /actor1/* list. I'm pretty sure that code's template is right but there is probably something wrong with syntax. I don't get any errors while launching the .world file that contains following code:

<actor name="actor1">
  <pose>0 1 1.25 0 0 0</pose>
  <skin>
    <filename>walk.dae</filename>
    <scale>1.0</scale>
  </skin>
  <link name="imu_base">
    <frame name="imu_leg">
      <pose frame="actor1::RightLeg">0 0 0 0 0 0</pose>
    </frame>
    <pose>0 0 0 0 0 0</pose>
    <visual name="imu_base_visual">
      <pose>0 0 0 0 0 0</pose>
      <geometry>
        <box>
          <size>0.2 0.2 0.2</size> <!-- EASIER DEBUGGING -->
        </box>
      </geometry>
      <material>
        <script>
          <uri>model://actor_imu/materials/actor_imu.material</uri>
          <name>actor_imu/base</name>
        </script>
      </material>
    </visual>
    <sensor name="actor_imu" type="imu">
      <visualize>true</visualize>
      <plugin name="actor_imu" filename="libactor_imu.so"/>
      <update_rate>100</update_rate> <!-- EASIER DEBUGGING -->
      <always_on>1</always_on>
    </sensor>
  </link>
  <joint name="actor1::imu_fix" type="fixed">
    <parent>actor1::RightLeg</parent>
    <child>imu_base</child>
  </joint>
  <animation name="walking">
    <filename>walk.dae</filename>
    <scale>1.000000</scale>
    <interpolate_x>true</interpolate_x>
  </animation>
  <plugin name="actor1_plugin" filename="libActorPlugin.so">
    <target>0 -5 1.2138</target>
    <target_weight>1.15</target_weight>
    <obstacle_weight>1.8</obstacle_weight>
    <animation_factor>5.1</animation_factor>
    <ignore_obstacles>
      <model>cafe</model>
      <model>ground_plane</model>
    </ignore_obstacles>
  </plugin>
</actor>

I checked other questions before, it is kind of related to 15389 and 14006.

Thanks in advance

EDIT: As @chapulina suggested, I ran gazebo in verbose mode and this is the output:

[Wrn] [GuiIface.cc:196] g/gui-plugin is really loading a SystemPlugin. To load a GUI plugin please use --gui-client-plugin 
[ INFO] [1544379941.319388836]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1544379941.320842043]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[ INFO] [1544379941.391440800]: Finished loading Gazebo ROS API Plugin.
[Msg] Waiting for master.
[ INFO] [1544379941.392690107]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[Msg] Connected to gazebo master @ http://127.0.0.1:11345
[Msg] Publicized address: 192.168.1.156
[Err] [InsertModelWidget.cc:336] Missing model.config for model "/home/rayvburn/ped_sim_ws/src/incare_people_sim/actor_imu/materials"
[Err] [InsertModelWidget.cc:336] Missing model.config for model "/home/rayvburn/ped_sim_ws/src/incare_people_sim/actor_imu/src"
[Err] [InsertModelWidget.cc:336] Missing model.config for model "/home/rayvburn/ped_sim_ws/src/people_sim/turtlebot3_simulations/turtlebot3_gazebo/models/turtlebot3_autorace"
[ INFO] [1544379942.355888232]: waitForService: Service [/gazebo/set_physics_properties] is now available.
[ INFO] [1544379942.371552291]: waitForService: Service [/gazebo/set_physics_properties] is now available.
IMU sensor succesfully found
[ INFO] [1544379942.476708789]: Physics dynamic reconfigure ready ...