Python-learning-SMACH-QA

• Question
  
  /usr/bin/python3.4 /home/evan/PycharmProjects/smach_projects/GettingStarted.py

Traceback (most recent call last):
  File "/home/evan/PycharmProjects/smach_projects/GettingStarted.py", line 2, in <module>
    import roslib;roslib.load_manifest('smach_projects')
  File "/opt/ros/indigo/lib/python2.7/dist-packages/roslib/__init__.py", line 50, in <module>
    from roslib.launcher import load_manifest
  File "/opt/ros/indigo/lib/python2.7/dist-packages/roslib/launcher.py", line 42, in <module>
    import rospkg
ImportError: No module named 'rospkg'

Process finished with exit code 1

• Answer

Because we didnot install python3.4 package in the ros folder(/opt/ros/indigo/lib) , we just installed rospkg for python 2.7.6 so can not find the rospkg for python 3.4. We can manually install rospkg for python 3.4 but notice that only one rospkg can be installed that means we can not install rospkg for both python 2.7 and python 3.4.

• Question
  

  • Answer:-smach_viewer的Graph view不能显示状态图

• Question
  [ERROR] [WallTime: 1496741655.591969] Error raised during SMACH container construction:
  Traceback (most recent call last):
  
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 123, in main
      smach.StateMachine.add('find_area', State_find_area(),
  
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 63, in __init__
      result_cb = self.cb_result)
  
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 37, in __init__
      smach_ros.SimpleActionState.__init__(self,action_name,action_spec,goal,goal_key,goal_slots,goal_cb,goal_cb_args
  , result_key,result_slots,result_cb,result_cb_args,result_cb_kwargs,input_keys,output_keys,outcomes, exec_timeout,p
  reempt_timeout,server_wait_timeout)
  
    File "/opt/ros/indigo/lib/python2.7/dist-packages/smach_ros/simple_action_state.py", line 173, in __init__
      if not all([s in action_spec().action_result.result.__slots__ for s in result_slots]):
  
  TypeError: 'instancemethod' object is not iterable
  Traceback (most recent call last):
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 135, in <module>
      main()
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 123, in main
      smach.StateMachine.add('find_area', State_find_area(),
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 63, in __init__
      result_cb = self.cb_result)
    File "/home/evan/workspace/roboware/my_catkin_ws/src/smach_package/src/cleanContainer.py", line 37, in __init__
      smach_ros.SimpleActionState.__init__(self,action_name,action_spec,goal,goal_key,goal_slots,goal_cb,goal_cb_args
  , result_key,result_slots,result_cb,result_cb_args,result_cb_kwargs,input_keys,output_keys,outcomes, exec_timeout,p
  reempt_timeout,server_wait_timeout)
    File "/opt/ros/indigo/lib/python2.7/dist-packages/smach_ros/simple_action_state.py", line 173, in __init__
      if not all([s in action_spec().action_result.result.__slots__ for s in result_slots]):
  TypeError: 'instancemethod' object is not iterable
  
  • Answer
    
        def __init__(self, # Action info

                action_name = 'default_action',

                action_spec = defaultAction,

                # Default goal 

                goal = None,

                goal_key = None,

                goal_slots = [],

                goal_cb = None,

                goal_cb_args = [],

                goal_cb_kwargs = {},

                # Result modes

                result_key = None,

                result_slots = [],

                result_cb = None,

                result_cb_args = [],

                result_cb_kwargs = {},

                # Keys

                input_keys = [],

                output_keys = [],

                outcomes = [],

                # Timeouts

                exec_timeout = None,

                preempt_timeout = rospy.Duration(60.0),

                server_wait_timeout = rospy.Duration(60.0)):

            smach_ros.SimpleActionState.__init__(self,action_name,action_spec,goal,goal_key,goal_slots,goal_cb,goal_cb_args,goal_cb_kwargs(forget adding this param to cause the wrong param order), result_key,result_slots,result_cb,result_cb_args,result_cb_kwargs,input_keys,output_keys,outcomes, exec_timeout,preempt_timeout,server_wait_timeout)

    
    
• Question
  [ERROR] [WallTime: 1496742757.805075] InvalidTransitionError: State machine failed consistency check:
          State 'find_area' references unregistered outcomes: ['preempted', 'aborted']
  
          Available states: ['finish', 'BAR', 'find_area']
  [ERROR] [WallTime: 1496742757.805399] Container consistency check failed.
  
  • Answer
    
    smach.StateMachine.add('find_area', State_find_area(), 

                                   transitions={'succeeded':'finish', 

                                                'fail':'find_area',

                                                'aborted':'aborted',

                                                'preempted':'aborted'},#forget adding these two lines,so the state machine can not form complete outcome diagram.
    

                                   remapping={'find_wall_area':'area'})
    
    
• Question
  [ERROR] [WallTime: 1496743305.298023] InvalidUserCodeError: Reading from SMACH userdata key 'find_wall_area' but the only keys that were declare
  d as input to this state were: (). This key needs to be declaread as input to this state.
  [ERROR] [WallTime: 1496743305.298158] State 'find_area' failed to execute.
  
  • Answer
    
    smach.StateMachine.add('find_area', State_find_area(), 

                                   transitions={'succeeded':'plan_path', 

                                                'fail':'find_area',

                                                'aborted':'aborted',

                                                'preempted':'aborted'},

                                   remapping={'find_wall_area':'area',#This line for input_key named 'find_wall_area'
    

                                                'find_wall_area':'area'})#This line for output_key named 'find_wall_area'
• Question
  When adding a new action file area.action , there is an error happened when building.
  
   Generating .msg files for action smach_package/area /home/evan/workspace/roboware/my_catkin_ws/src/smach_package/action/area.action

  Traceback (most recent call last):

    File "/opt/ros/indigo/share/actionlib_msgs/cmake/../../../lib/actionlib_msgs/genaction.py", line 136, in <module>

      if __name__ == '__main__': main()

    File "/opt/ros/indigo/share/actionlib_msgs/cmake/../../../lib/actionlib_msgs/genaction.py", line 97, in main

      raise ActionSpecException("%s: wrong number of pieces, %d"%(filename,len(pieces)))

  __main__.ActionSpecException: /home/evan/workspace/roboware/my_catkin_ws/src/smach_package/action/area.action: wrong number of pieces, 1

  Generating for action area

  CMake Error at /opt/ros/indigo/share/catkin/cmake/safe_execute_process.cmake:11 (message):
  • Answer
    
    #goal definition

    geometry_msgs::PointStamped  origin

    
    

    #result definition

    geometry_msgs::PolygonStamped area

    
    

    #feedback definition

    geometry_msgs::PolygonStamped area
    replace the double comma to reverse slash and add two seperators
    
    #goal definition

    geometry_msgs/PointStamped  origin

    ---
    

    #result definition

    geometry_msgs/PolygonStamped area

    ---
    

    #feedback definition

    geometry_msgs/PolygonStamped area
  • if there is another error occurring
    CMake Error at /home/evan/workspace/roboware/my_catkin_ws/build/smach_package/cmake/smach_package-genmsg.cmake:3 (message):
      Could not find messages which
      '/home/evan/workspace/roboware/my_catkin_ws/devel/share/smach_package/msg/areaAction.msg'
      depends on.  Did you forget to specify generate_messages(DEPENDENCIES ...)?
    
      Cannot locate message [PointStamped]: unknown package [geometry_msgs] on
      search path [{{'smach_package':
      ['/home/evan/workspace/roboware/my_catkin_ws/devel/share/smach_package/msg'],
      'actionlib_msgs': ['/opt/ros/indigo/share/actionlib_msgs/cmake/../msg'],
      'std_msgs': ['/opt/ros/indigo/share/std_msgs/cmake/../msg']}}]
    • Answer
      
      ## Generate added messages and services with any dependencies listed here

      generate_messages(DEPENDENCIES

        actionlib_msgs

        geometry_msgs   ## Add this line for support the geometry_msgs/polygonStamped message
      

        std_msgs

      )
      find_package(catkin REQUIRED COMPONENTS

        actionlib_msgs

        message_generation

        rospy

        std_msgs

        geometry_msgs  ## Add this line when using geometry_msgs to generate messages
      

      )
• Question
  e_action_server.py", line 289, in executeLoop
      self.execute_callback(goal)
    File "/home/evan/catkin_ws/src/sim_platform/src/path_planner.py",
   line 99, in execute_cb
      self._sas.set_succeeded(result)
    File "/opt/ros/indigo/lib/python2.7/dist-packages/actionlib/simpl
  e_action_server.py", line 162, in set_succeeded
      self.current_goal.set_succeeded(result, text)
    File "/opt/ros/indigo/lib/python2.7/dist-packages/actionlib/serve
  r_goal_handle.py", line 195, in set_succeeded
      self.action_server.publish_result(self.status_tracker.status, r
  esult)
    File "/opt/ros/indigo/lib/python2.7/dist-packages/actionlib/actio
  n_server.py", line 182, in publish_result
      self.result_pub.publish(ar)
    File "/opt/ros/indigo/lib/python2.7/dist-packages/rospy/topics.py
  ", line 856, in publish
      raise ROSSerializationException(str(e))
  ROSSerializationException: <class 'struct.error'>: 'required argume
  nt is not a float' when writing 'x: 0
  y:
    - 0.208178028592
    - -0.0186330676772
    - 0
  z: 0.0'
  • Answer
    
    for index,waypoint in enumerate(self.path):  ## forget add index ,enumerate will firstly set index .Otherwise waypoint[0] will be set as index.