ROS-除非启用allow_none，否则启动参数“不能封送”。

Question

我的发行版是ROS动力版

我试图启动两个节点: pid_controller.py和throttle_interpolator.py，但是ROS不断地给我返回错误：

“除非启用allow_none，否则不能封送任何邮件”

这个问题可能与vesc.yaml有关，但老实说，我已经不知道了。一直令人沮丧。

我的集线器：controller

我只在以下方面遇到麻烦：

<arg name="vesc_config" default="$(find boat_controller)/config/vesc.yaml" />
        <rosparam file="$(arg vesc_config)" command="load" ns="/"/>

并使用

<node pkg="boat_controller" type="throttle_interpolator.py" name="throttle_interpolator">

        </node>

当它被评论的时候，一切都很好。

我的发射文件：

<?xml version="1.0"?>
<launch>
    <arg name="vesc_config" default="$(find boat_controller)/config/vesc.yaml" />
    <rosparam file="$(arg vesc_config)" command="load" ns="/"/>

    <node pkg="boat_controller" type="pid_controller.py" name="pid_controller" output="screen">
          <param name="yawKp" value="0.2" type="double"/>
          <param name="yawKi" value="0.0" type="double"/>
          <param name="yawKd" value="0.0" type="double"/>

          <param name="velKp" value="0.7" type="double"/>
          <param name="velKi" value="0.3" type="double"/>
          <param name="velKd" value="0.0" type="double"/>

          <param name="start_engaged" value="true" type="bool"/>
          <param name="yaw_cntrl" value="true" type="bool"/>
          <param name="vel_cntrl" value="true" type="bool"/>

    </node> 

    <node pkg="boat_controller" type="throttle_interpolator.py" name="throttle_interpolator">

    </node>

</launch>

在尝试运行启动文件后，终端输出如下：

ubuntu-13028.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://ubuntu:33415/

SUMMARY
========

PARAMETERS
 * /commands/motor/speed_left: commands/motor/sp...
 * /commands/motor/speed_right: commands/motor/sp...
 * /commands/motor/unsmoothed_speed: cmd_drive
 * /commands/servo/position: None
 * /commands/servo/unsmoothed_position: None
 * /max_rpm_acceleration: 100
 * /max_servo_speed: 3.2
 * /pid_controller/start_engaged: True
 * /pid_controller/velKd: 0.0
 * /pid_controller/velKi: 0.3
 * /pid_controller/velKp: 0.7
 * /pid_controller/vel_cntrl: True
 * /pid_controller/yawKd: 0.0
 * /pid_controller/yawKi: 0.0
 * /pid_controller/yawKp: 0.2
 * /pid_controller/yaw_cntrl: True
 * /rosdistro: kinetic
 * /rosversion: 1.12.14
 * /rpm_to_erpm_gain: 7
 * /servo_smoother_rate: 75.0
 * /speed_to_erpm_offset: 0.0
 * /steering_angle_to_servo_gain: -1.2135
 * /steering_angle_to_servo_offset: 0.5304
 * /tachometer_ticks_to_meters_gain: 0.00225
 * /throttle_smoother_rate: 100
 * /vesc_driver/brake_max: 200000.0
 * /vesc_driver/brake_min: -20000.0
 * /vesc_driver/current_max: 20.0
 * /vesc_driver/current_min: 0.0
 * /vesc_driver/duty_cycle_max: 0.0
 * /vesc_driver/duty_cycle_min: 0.0
 * /vesc_driver/port: /dev/ttyACM0
 * /vesc_driver/position_max: 0.0
 * /vesc_driver/position_min: 0.0
 * /vesc_driver/servo_max: 0.85
 * /vesc_driver/servo_min: 0.15
 * /vesc_driver/speed_max: 3250
 * /vesc_driver/speed_min: -3250

NODES
  /
    pid_controller (boat_controller/pid_controller.py)
    throttle_interpolator (boat_controller/throttle_interpolator.py)

ROS_MASTER_URI=http://localhost:11311

load_parameters: unable to set parameters (last param was [/vesc_driver/position_max=0.0]): cannot marshal None unless allow_none is enabled
Traceback (most recent call last):
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/__init__.py", line 306, in main
    p.start()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/parent.py", line 279, in start
    self.runner.launch()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/launch.py", line 657, in launch
    self._setup()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/launch.py", line 644, in _setup
    self._load_parameters()
  File "/opt/ros/kinetic/lib/python2.7/dist-packages/roslaunch/launch.py", line 338, in _load_parameters
    r  = param_server_multi()
  File "/usr/lib/python2.7/xmlrpclib.py", line 1006, in __call__
    return MultiCallIterator(self.__server.system.multicall(marshalled_list))
  File "/usr/lib/python2.7/xmlrpclib.py", line 1243, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1596, in __request
    allow_none=self.__allow_none)
  File "/usr/lib/python2.7/xmlrpclib.py", line 1094, in dumps
    data = m.dumps(params)
  File "/usr/lib/python2.7/xmlrpclib.py", line 638, in dumps
    dump(v, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 660, in __dump
    f(self, value, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 719, in dump_array
    dump(v, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 660, in __dump
    f(self, value, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 741, in dump_struct
    dump(v, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 660, in __dump
    f(self, value, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 719, in dump_array
    dump(v, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 660, in __dump
    f(self, value, write)
  File "/usr/lib/python2.7/xmlrpclib.py", line 664, in dump_nil
    raise TypeError, "cannot marshal None unless allow_none is enabled"
TypeError: cannot marshal None unless allow_none is enabled

Answer 1

您需要将参数unsmoothed_position和position设置为某些值(例如，我将它们设置为0.0)。

下一个错误来自这样一个事实:您将包命名为boat_pid_controller (文件夹本身)，启动文件中的所有内容都被命名为CMakelists.txt，而package.xml有boat_controller:您需要选择一个一致的名称，这样当您将包命名为find时，您实际上就可以找到它。