Thermal Camera Plugin not defined in SDF error

I'm trying to use the [hector_gazebo_thermal_camera](http://answers.gazebosim.org/questions/ask/) in a simulation for my graduation project. It returns the error: **Warning [parser.cc:778]** XML Element[sensor:camera], child of element[link] not defined in SDF. Ignoring[sensor:camera]. You may have an incorrect SDF file, or an sdformat version that doesn't support this element. I've made a simple code only with the camera and the plugin in order to validate the plugin: This is the urdf.xacro file: Gazebo/Blue and this is the .gazebo.xacro file that contains the plugin: ${image_width} ${image_height}${image_format}${hfov}0.01100${update_rate}true${update_rate}${camera_name}${image_topic_name}${camera_info_topic_name}${frame_id}${hack_baseline}${(image_width+1)/2}${(image_width+1)/2}${(image_height+1)/2}${focal_length}0.000000010.000000010.000000010.000000010.00000001trueGazebo/Blue I'm using ros **Kinetic** and **Gazebo 7** , i've found on github some projects that uses this thermal camera, and I took them as base , the [race_pr2](https://github.com/cebremer/sap/blob/39cde1c960a856c0512335a49851238cb00cc097/uos_active_perception/active_perception_evaluation/urdf/race_pr2.urdf) but they are only on ros indigo. And i don't use aditional paramaters to my launch file: I already know that some arguments changed in the sdf definitions, and have already used another plugins like stereo camera and the hector sonar plugins.