How to solve 'Failed to load r_cart' ?

edit

I followed Teleop PR2 arm in simulation.

I run:

  roslaunch pr2_gazebo pr2_empty_world.launch

And jtteleop launch file:

  sam@sam:~/code/ros/test$ roslaunch jtteleop.launch 
  ... logging to /home/sam/.ros/log/cab3d0b6-c687-11e1-bd65-20cf30a23845/roslaunch-sam-26533.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://sam:57702/

  SUMMARY
  ========

  PARAMETERS
   * /r_cart/joint_max_effort/r_forearm_roll_joint
   * /r_cart/pose_command_filter
   * /r_cart/joint_max_effort/r_shoulder_pan_joint
   * /r_cart/joint_feedforward/r_shoulder_lift_joint
   * /r_cart/joint_feedforward/r_elbow_flex_joint
   * /r_cart/joint_max_effort/r_wrist_flex_joint
   * /r_cart/joint_max_effort/r_upper_arm_roll_joint
   * /r_cart/joint_feedforward/r_shoulder_pan_joint
   * /rosdistro
   * /r_cart/vel_saturation_trans
   * /r_cart/joint_feedforward/r_wrist_roll_joint
   * /r_cart/cart_gains/trans/d
   * /rosversion
   * /r_cart/joint_max_effort/r_shoulder_lift_joint
   * /r_cart/cart_gains/trans/p
   * /r_cart/type
   * /r_cart/tip_name
   * /r_cart/vel_saturation_rot
   * /r_cart/joint_feedforward/r_forearm_roll_joint
   * /r_cart/cart_gains/rot/p
   * /r_cart/root_name
   * /r_cart/jacobian_inverse_damping
   * /r_cart/joint_max_effort/r_elbow_flex_joint
   * /r_cart/k_posture
   * /r_cart/cart_gains/rot/d
   * /r_cart/joint_max_effort/r_wrist_roll_joint
   * /r_cart/joint_feedforward/r_upper_arm_roll_joint
   * /r_cart/joint_feedforward/r_wrist_flex_joint

  NODES
    /
      stop_r_arm (pr2_controller_manager/pr2_controller_manager)
      spawn_cart (pr2_controller_manager/spawner)

  ROS_MASTER_URI=http://localhost:11311

  core service [/rosout] found
  process[stop_r_arm-1]: started with pid [26551]
  process[spawn_cart-2]: started with pid [26552]
  [stop_r_arm-1] process has finished cleanly.
  log file: /home/sam/.ros/log/cab3d0b6-c687-11e1-bd65-20cf30a23845/stop_r_arm-1*.log
  [ERROR] [WallTime: 1341482270.896231] [32.088000] Failed to load r_cart

How to solve it?

Thank you~

I followed the answer.

I try this launch:

  <launch> 

  <node name="stop_r_arm" pkg="pr2_controller_manager" type="pr2_controller_manager" args="stop r_arm_controller"/>

  <rosparam ns="r_cart"> 
  type: robot_mechanism_controllers/JTTCartesianController 
  root_name: torso_lift_link 
  tip_name: r_gripper_tool_frame 
  k_posture: 25.0 
  jacobian_inverse_damping: 0.01 
  pose_command_filter: 0.01 
  cart_gains: 
  trans: 
  p: 800.0 
  d: 15.0 
  rot: 
  p: 80.0 
  d: 1.2 
  joint_feedforward: 
  r_shoulder_pan_joint: 3.33 
  r_shoulder_lift_joint: 1.16 
  r_upper_arm_roll_joint: 0.1 
  r_elbow_flex_joint: 0.25 
  r_forearm_roll_joint: 0.133 
  r_wrist_flex_joint: 0.0727 
  r_wrist_roll_joint: 0.0727 
  joint_max_effort: 
  r_shoulder_pan_joint: 11.88 
  r_shoulder_lift_joint: 11.64 
  r_upper_arm_roll_joint: 6.143 
  r_elbow_flex_joint: 6.804 
  r_forearm_roll_joint: 8.376 
  r_wrist_flex_joint: 5.568 
  r_wrist_roll_joint: 5.568

  vel_saturation_trans: 2.0 
  vel_saturation_rot: 4.0 
  </rosparam> 

  <node name="spawn_cart" pkg="pr2_controller_manager" type="spawner" args="r_cart"/> 
  </launch>

And I got this error:

  sam@sam:~/code/ros/test$ roslaunch t3.launch 
  ... logging to /home/sam/.ros/log/a8d96ed0-d495-11e1-a466-20cf30a23845/roslaunch-sam-12098.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://sam:32831/

  SUMMARY
  ========

  PARAMETERS
   * /r_cart/r_upper_arm_roll_joint
   * /r_cart/pose_command_filter
   * /r_cart/joint_max_effort
   * /r_cart/cart_gains
   * /r_cart/r_wrist_roll_joint
   * /r_cart/joint_feedforward
   * /r_cart/r_elbow_flex_joint
   * /r_cart/k_posture
   * /r_cart/p
   * /r_cart/trans
   * /rosdistro
   * /r_cart/vel_saturation_trans
   * /r_cart/r_wrist_flex_joint
   * /r_cart/rot
   * /rosversion
   * /r_cart/root_name
   * /r_cart/d
   * /r_cart/type
   * /r_cart/tip_name
   * /r_cart/vel_saturation_rot
   * /r_cart/r_forearm_roll_joint
   * /r_cart/jacobian_inverse_damping
   * /r_cart/r_shoulder_lift_joint
   * /r_cart/r_shoulder_pan_joint

  NODES
    /
      stop_r_arm (pr2_controller_manager/pr2_controller_manager)
      spawn_cart (pr2_controller_manager/spawner)

  ROS_MASTER_URI=http://localhost:11311

  core service [/rosout] found
  load_parameters: unable to set parameters (last param was [/r_cart/r_shoulder_pan_joint=11.88]): cannot marshal None unless allow_none is enabled
  Traceback (most recent call last):
    File "/opt/ros/electric/stacks/ros_comm/tools/roslaunch/src/roslaunch/__init__.py", line 252, in main
      p.start()
    File "/opt/ros/electric/stacks/ros_comm/tools/roslaunch/src/roslaunch/parent.py", line 265, in start
      self.runner.launch()
    File "/opt/ros/electric/stacks/ros_comm/tools/roslaunch/src/roslaunch/launch.py", line ...