ROS知识（10）----smach_viewer的Graph view不能显示状态图

1、问题

在运行ROS by Example 2--Indigo版本中，运行 smach_viewer,再运行巡逻，命令如下：

$ rosrun smach_viewer smach_viewer.py
$ rosrun rbx2_tasks patrol_smach.py

出现如下错误：

xception in thread Thread-5:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/opt/ros/indigo/lib/smach_viewer/smach_viewer.py", line 848, in _update_graph
    self.set_dotcode(dotstr,zoom=False)
  File "/opt/ros/indigo/lib/smach_viewer/smach_viewer.py", line 866, in set_dotcode
    if self.widget.set_dotcode(dotcode, None):
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/wxxdot.py", line 455, in set_dotcode
    self.set_xdotcode(xdotcode)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/wxxdot.py", line 483, in set_xdotcode
    self.graph = parser.parse()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 1146, in parse
    DotParser.parse(self)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 951, in parse
    self.parse_graph()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 960, in parse_graph
    self.parse_stmt()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 993, in parse_stmt
    self.parse_subgraph()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 974, in parse_subgraph
    self.parse_stmt()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 993, in parse_stmt
    self.parse_subgraph()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 974, in parse_subgraph
    self.parse_stmt()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 1009, in parse_stmt
    self.handle_node(id, attrs)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 1120, in handle_node
    shapes.extend(parser.parse())
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 608, in parse
    points = self.read_polygon()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 503, in read_polygon
    x, y = self.read_point()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 486, in read_point
    x = self.read_number()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/xdot/xdot.py", line 480, in read_number
    return int(self.read_code())
ValueError: invalid literal for int() with base 10: '402.67'

2、解决方案

将文件的480行的代码：

return int(self.read_code()) 

改成：

return int(float(self.read_code()))

来解决方案的来源：

1、ROS Indigo :Cannot show Graph View on smach_viewer

出来的效果图：

smach在机器人控制中太重要了，PR2开发中，发现如果不用一套完整的框架去执行任务，会导致代码的维护特别的繁杂，所以大佬们才开发这套smach状态机功能包，既然要用到，就不要走弯路了，最近试了几个任务的执行，深切体会，知道碰壁不如早点用起来它吧。