1.rplidar开启
2.turtlrbot bringup
3. 运行 roslaunch rbx1_nav gmapping_demo.launch 报如下错误：
MessageFilter [target=odom ]: Dropped 100.00% of messages so far. Please turn the [ros.gmapping.message_notifier] rosconsole logger to DEBUG for more information.
参考：https://answers.ros.org/question/246928/messagefilter-dropped-100-of-messages/
和问题 gmapping works in Gazebo but not on robot : https://answers.ros.org/question/218849/gmapping-works-in-gazebo-but-not-on-robot/
解决办法：
1.复制gmapping.launch 文件为gmapping_laser.launch
在 <arg name="scan_topic" default="scan" /> 下添加：
<node pkg="tf" type="static_transform_publisher" name="link1_broadcaster" args="1 0 0 0 0 0 base_link laser 100" />
2. 改gmapping.demo 应用gmapping_laser.launch。