At first,I run "roslaunch pitracker skeleton.launch" on the command line.And then the topic "/skeleton" came out.So I run "rosrun pitracker trackerbasecontroller.py" on the command line.And then the the topic "/cmdvel" came out.But the messages on the topic "/cmdvel" is always like this: linear: x: 0.0 y: 0.0 z: 0.0 angular: x: 0.0 y: 0.0 z: 0.0

So I call the service "setcommand",and then the window running the node "trackerbase_controller" shows as below:

"Traceback (most recent call last): File "/home/sven/rosworkspace/pitracker/bin/trackerbasecontroller.py", line 254, in TrackerBaseController() File "/home/sven/rosworkspace/pitracker/bin/trackerbasecontroller.py", line 82, in init if self.trackercommand == 'STOP' or (self.skeleton['confidence']['left_hand'] < 0.5 and self.skeleton['confidence']['right_hand'] < 0.5): KeyError: 'lefthand' [INFO] [WallTime: 1338390962.048561] Shutting down Tracker Base Controller Node." Obviously,the node "trackerbasecontroler" stopped running. Is there any one who can help me?