采坑：Didn‘t receive robot state (joint angles) with recent timestamp within 1 seconds.

错误信息：

Didn't receive robot state (joint angles) with recent timestamp within 1 seconds.Check clock synchronization if your are running ROS across multiple machines

我的环境，joint_states 由gazebo发布，move_group订阅这个话题，其中moveit中源码为：

经过排查发现gazebo发布的joint_state 时间戳余ros时间戳相差甚远，不同步。

解决方法：

在gazebo发起的launch文件中需要显式地将参数use_sim_time 设置为true才行

<arg name="use_sim_time" default="true"/>

  <!-- launch the gazebo simulator and spawn the robot -->
  <include file="$(find robot_moveit_config)/launch/gazebo.launch" >
    <arg name="paused" value="$(arg paused)"/>
    <arg name="gazebo_gui" value="$(arg gazebo_gui)"/>
    <arg name="urdf_path" value="$(arg urdf_path)"/>
    <arg name="use_sim_time" value="$(arg use_sim_time)"/>

  </include>