When I tried to run turtlebot_playground.launch in turtlebot_gazebo, gazebo window with turtlebot with some objects appeard, but turtlebot kept rotating and some topics to control turtlebot couldn't be found such as /mobile_base/commands/motor_power and /mobile_base/commands/velocity. How to fix it?

On ros-hydro

roslaunch turtlebot_gazebo turtlebot_playground.launch ... logging to /home/*/.ros/log/624dfffa-6334-11e4-b3da-0022fbb250b4/roslaunch-IMI-T400s-19011.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.

started roslaunch server http://IMI-T400s:41653/

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)

ROS_MASTER_URI=http://localhost:11311

core service [/rosout] found process[gazebo-1]: started with pid [19032] process[gazebo_gui-2]: started with pid [19038] process[spawn_turtlebot_model-3]: started with pid [19043] Gazebo multi-robot simulator, version 1.9.6 Copyright (C) 2014 Open Source Robotics Foundation. Released under the Apache 2 License. http://gazebosim.org

Gazebo multi-robot simulator, version 1.9.6 Copyright (C) 2014 Open Source Robotics Foundation. Released under the Apache 2 License. http://gazebosim.org

process[robot_pose_ekf-4]: started with pid [19049] process[mobile_base_nodelet_manager-5]: started with pid [19086] process[cmd_vel_mux-6]: started with pid [19089] Msg Waiting for master.process[robot_state_publisher-7]: started with pid [19124] process[laserscan_nodelet_manager-8]: started with pid [19147] Msg Waiting for master Msg Connected to gazebo master @ http://127.0.0.1:11345 Msg Publicized address: 192.168.2.103 process[depthimage_to_laserscan-9]: started with pid [19179]

Msg Connected to gazebo master @ http://127.0.0.1:11345 Msg Publicized address: 192.168.2.103 Dbg plugin model name: turtlebot Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized) Warning [RaySensor.cc:283] ranges not constructed yet (zero sized ...