The Launch file could not launch in the package rbx1_nav !

edit

I run the command in the different terminal :

roslaunch rbx1_bringup fake_turtlebot.launch
rosrun rviz rviz -d `rospack find rbx1_nav`/sim.rviz
rosrun rbx1_nav timed_out_and_back.py

it works good,but the fellow command have some problems:

roslaunch rbx1_nav keyboard_teleop.launch

it gives these message:

SUMMARY
========
PARAMETERS
* /rosdistro: indigo
* /rosversion: 1.11.20
* /turtlebot_teleop_keyboard/scale_angular: 0.4
* /turtlebot_teleop_keyboard/scale_linear: 0.1
NODES
turtlebot_teleop_keyboard (turtlebot_teleop/turtlebot_teleop_key)
ROS_MASTER_URI=http://localhost:11311
core service [/rosout] found
ERROR: cannot launch node of type [turtlebot_teleop/turtlebot_teleop_key]: turtlebot_teleop
ROS path [0]=/opt/ros/indigo/share/ros
ROS path [1]=/home/wangfang/catkin_ws/src/rbx1
ROS path [2]=/home/wangfang/catkin_ws/src
ROS path [4]=/opt/ros/indigo/stacks
No processes to monitor
shutting down processing monitor...

I haven't modify the package.

anyone can tell me where the problems are? I am a freshman in ROS , Thank you verymuch.