laser_scan_matcher 的 tos tf 设置 vrep/scan 和 slam

Question

我正在我的环境中尝试这个。

https://sudonull.com/post/21487-Mapping-and-localization-of-a-mobile-robot-in-ROS-without-odometry-using-laser_scan_matcher

我得到了一个模拟环境：

主题：vrep/scan

使用 TF：base_link -> laser_link

那我就用laser_scan_matcher

我得到了 TF：地图 -> 奥多姆。

我需要来自 odom 的 TF -> laser_link 用于 gmapping SLAM。

但我没有弄清楚如何创建这样的link。

我的启动文件如下：

<launch>

  <node pkg="laser_scan_matcher" type="laser_scan_matcher_node" 
    name="laser_scan_matcher_node" output="screen">
    <param name="scan" value = "/vrep/scan"/>
    <param name="fixed_frame" value = "odom"/>
    <param name="use_alpha_beta" value="true"/>
    <param name="max_iterations" value="10"/>
  </node>

  <node pkg="gmapping" type="slam_gmapping" name="slam_gmapping" output="screen">
    <param name="scan" value = "/vrep/scan"/>
    <param name="map_udpate_interval" value="1.0"/>
    <param name="delta" value="0.02"/>
  </node>

</launch>

我读了这个，但我还是想不通。 https://answers.ros.org/question/10909/combining-laser_scan_matcher-with-gmapping/

或者我的问题实际上是如何使用正确的启动文件将 odom 连接到 baselink？非常感谢提示。

roslaunch

    Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://ros-vm:38189/

SUMMARY
========

PARAMETERS
 * /laser_scan_matcher_node/fixed_frame: odom
 * /laser_scan_matcher_node/max_iterations: 10
 * /laser_scan_matcher_node/publish_odom: True
 * /laser_scan_matcher_node/scan: /vrep/scan
 * /laser_scan_matcher_node/use_alpha_beta: True
 * /laser_scan_matcher_node/use_odom: True
 * /rosdistro: melodic
 * /rosversion: 1.14.5
 * /slam_gmapping/delta: 0.02
 * /slam_gmapping/map_udpate_interval: 1.0
 * /slam_gmapping/scan: /vrep/scan

NODES
  /
    laser_scan_matcher_node (laser_scan_matcher/laser_scan_matcher_node)
    slam_gmapping (gmapping/slam_gmapping)

ROS_MASTER_URI=http://localhost:11311

process[laser_scan_matcher_node-1]: started with pid [7540]
process[slam_gmapping-2]: started with pid [7545]
[ INFO] [1589974736.966492078]: Starting LaserScanMatcher

日志：

 rosnode info laser_scan_matcher_node
--------------------------------------------------------------------------------
Node [/laser_scan_matcher_node]
Publications:
 * /pose2D [geometry_msgs/Pose2D]
 * /rosout [rosgraph_msgs/Log]
 * /tf [tf2_msgs/TFMessage]

Subscriptions:
 * /clock [rosgraph_msgs/Clock]
 * /imu/data [unknown type]
 * /odom [unknown type]
 * /scan [unknown type]
 * /tf [tf2_msgs/TFMessage]
 * /tf_static [unknown type]

Services:
 * /laser_scan_matcher_node/get_loggers
 * /laser_scan_matcher_node/set_logger_level


contacting node http://ros-vm:34349/ ...
Pid: 7062
Connections:
 * topic: /rosout
    * to: /rosout
    * direction: outbound (35035 - 10.0.2.15:52152) [17]
    * transport: TCPROS
 * topic: /tf
    * to: /laser_scan_matcher_node
    * direction: outbound
    * transport: INTRAPROCESS
 * topic: /tf
    * to: /rqt_gui_py_node_6989
    * direction: outbound (35035 - 10.0.2.15:52134) [14]
    * transport: TCPROS
 * topic: /tf
    * to: /slam_gmapping
    * direction: outbound (35035 - 10.0.2.15:52164) [11]
    * transport: TCPROS
 * topic: /clock
    * to: /vrep_ros_interface (http://ros-vm:35741/)
    * direction: inbound (56132 - ros-vm:60019) [12]
    * transport: TCPROS
 * topic: /tf
    * to: /laser_scan_matcher_node (http://ros-vm:34349/)
    * direction: inbound
    * transport: INTRAPROCESS
 * topic: /tf
    * to: /vrep_ros_interface (http://ros-vm:35741/)
    * direction: inbound (56134 - ros-vm:60019) [18]
    * transport: TCPROS
 * topic: /tf
    * to: /slam_gmapping (http://ros-vm:38313/)
    * direction: inbound (60954 - ros-vm:54021) [10]
    * transport: TCPROS


 rostopic list -v

Published topics:
 * /map_metadata [nav_msgs/MapMetaData] 1 publisher
 * /vrep/image [sensor_msgs/Image] 1 publisher
 * /vrep/scan [sensor_msgs/LaserScan] 1 publisher
 * /pose2D [geometry_msgs/Pose2D] 1 publisher
 * /rosout [rosgraph_msgs/Log] 4 publishers
 * /tf [tf2_msgs/TFMessage] 3 publishers
 * /clock [rosgraph_msgs/Clock] 1 publisher
 * /rosout_agg [rosgraph_msgs/Log] 1 publisher
 * /map [nav_msgs/OccupancyGrid] 1 publisher
 * /slam_gmapping/entropy [std_msgs/Float64] 1 publisher




rosnode list
/laser_scan_matcher_node
/rosout
/rqt_gui_py_node_6989
/slam_gmapping
/vrep_ros_interface

Answer 1

从rosnode info laser_scan_matcher_node可以看出，该节点订阅了主题scan。

在 rostopic list -v 的输出中没有该主题的发布者。该命令还列出了您未包含在问题中的订阅者。您尝试在启动文件中设置的主题 /vrep/scan 有一个发布者。从理论上讲，可以使用参数来提供 input/output 主题，但这必须在节点中实现。通常这不是必需的，所以大多数节点可能不会这样做。

您需要在启动文件中使用 remap 标签而不是 param 标签来重新映射主题。 Roslaunch XML wiki.

你的启动文件应该是这样的，扫描参数替换为重新映射：

<launch>

  <node pkg="laser_scan_matcher" type="laser_scan_matcher_node" 
    name="laser_scan_matcher_node" output="screen">
    <remap from="scan" to="/vrep/scan"/>
    <param name="fixed_frame" value = "odom"/>
    <param name="use_alpha_beta" value="true"/>
    <param name="max_iterations" value="10"/>
  </node>

  <node pkg="gmapping" type="slam_gmapping" name="slam_gmapping" output="screen">
    <remap from="scan" to="/vrep/scan"/>
    <param name="map_udpate_interval" value="1.0"/>
    <param name="delta" value="0.02"/>
  </node>

</launch>

不确定这是否会解决您的所有问题。

此外 to="/vrep/scan" 中的前导 / 在重新映射主题时非常重要，需要一些时间来适应，我建议阅读 this page 以了解一些内容正在那里进行。 from="scan" 中缺失的前导 / 同样重要。

进行此更改后，检查 slam_gmapping 和 laser_scan_matcher_node 节点是否都订阅了 /vrep/scan rosnode info ...

laser_scan_matcher 的 tos tf 设置 vrep/scan 和 slam

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