How to stop moving of turtlebot on ROS Hydro Gazebo?

edit

I run the following instructions to launch turtlebot on gazebo:

export TURTLEBOT_BASE=create
export TURTLEBOT_STACKS=circles
export TURTLEBOT_3D_SENSOR=asus_xtion_pro
roslaunch turtlebot_gazebo turtlebot_empty_world.launch

I make sure I do not send any twist but the robot move autonomously.

Here are two pictures to verify this:

How to solve this?

Thank you very much!

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The following is this computer ubuntu 12.04 64bits ROS hydro gazebo messages:

sam@sam:~$ roslaunch turtlebot_gazebo turtlebot_empty_world.launch
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
... logging to /home/sam/.ros/log/418c5ed8-873a-11e7-b74c-b8ee65344b7e/roslaunch-sam-14013.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
started roslaunch server http://sam:39531/

SUMMARY
========

PARAMETERS
 * /cmd_vel_mux/yaml_cfg_file
 * /depthimage_to_laserscan/output_frame_id
 * /depthimage_to_laserscan/range_min
 * /depthimage_to_laserscan/scan_height
 * /robot_description
 * /robot_pose_ekf/freq
 * /robot_pose_ekf/imu_used
 * /robot_pose_ekf/odom_used
 * /robot_pose_ekf/output_frame
 * /robot_pose_ekf/sensor_timeout
 * /robot_pose_ekf/vo_used
 * /robot_state_publisher/publish_frequency
 * /rosdistro
 * /rosversion
 * /use_sim_time

NODES
  /
    cmd_vel_mux (nodelet/nodelet)
    depthimage_to_laserscan (nodelet/nodelet)
    gazebo (gazebo_ros/gzserver)
    gazebo_gui (gazebo_ros/gzclient)
    laserscan_nodelet_manager (nodelet/nodelet)
    mobile_base_nodelet_manager (nodelet/nodelet)
    robot_pose_ekf (robot_pose_ekf/robot_pose_ekf)
    robot_state_publisher (robot_state_publisher/robot_state_publisher)
    spawn_turtlebot_model (gazebo_ros/spawn_model)

auto-starting new master
process[master]: started with pid [14042]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to 418c5ed8-873a-11e7-b74c-b8ee65344b7e
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
process[rosout-1]: started with pid [14056]
started core service [/rosout]
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
process[gazebo-2]: started with pid [14071]
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
WARNING: Package name "sam_receive_gazebo_topic_openCV_publish_image_topic" does not follow the naming conventions. It should start with a lower case letter and only contain lower case letters, digits and underscores.
process[gazebo_gui-3]: started with pid ...