1、ubuntu mate 开机启动

开始试了很多方法都不行，注意不要输错用户名，不然进不了系统了（进不了解决方法，找个电脑读一下这个turtlebot3系统所在的sd卡，把以前的/usr/share/lightdm/lightdm.conf.d/60-lightdm-gtk-greeter.conf文件恢复一下）

树莓派安装Ubuntu Mate 设置自动启动需要修改文件* /usr/share/lightdm/lightdm.conf.d/60-lightdm-gtk-greeter.conf*

sudo vim /usr/share/lightdm/lightdm.conf.d/60-lightdm-gtk-greeter.conf

如果提示文件为只读则修改该文件的权限为最高权限

cd /usr/share/lightdm/lightdm.conf.d/
chmod 777 60-lightdm-gtk-greeter.conf

添加自动登录命令

autologin-user=yourusername

保存，重启

reboot

2、跑salm出现 ar-track-alvar 包找不到的问题

解决方法：这个包要通过

sudo apt-get install ros-kinetic-ar-track-alvar

安装，不要git clone代码编译，编译代码会出错，如果下载了代码，请把代码我编译的 ar-track-alvar 相关的都删除。

如果有以下问题
-- Could not find the required component 'ar_track_alvar_msgs'. The following CMake error indicates that you either need to install the package with the same name or change your environment so that it can be found.
CMake Error at /opt/ros/kinetic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
Could not find a package configuration file provided by
"ar_track_alvar_msgs" with any of the following names:

ar_track_alvar_msgsConfig.cmake
ar_track_alvar_msgs-config.cmake

Add the installation prefix of "ar_track_alvar_msgs" to CMAKE_PREFIX_PATH
or set "ar_track_alvar_msgs_DIR" to a directory containing one of the above
files. If "ar_track_alvar_msgs" provides a separate development package or
SDK, be sure it has been installed.
Call Stack (most recent call first):
turtlebot3_applications/turtlebot3_automatic_parking_vision/CMakeLists.txt:10 (find_package)

请执行

sudo apt-get install ros-kinetic-ar-track-alvar-msgs

３OpenCR 报驱动相关的问题

创客上说了一大堆，不用管，还是参考http://emanual.robotis.com/docs/en/platform/turtlebot3/opencr_setup/#opencr-setup上的最多用 Shell Script,执行一下

 export OPENCR_PORT=/dev/ttyACM0
 export OPENCR_MODEL=burger
 rm -rf ./opencr_update.tar.bz2
wget https://github.com/ROBOTIS-GIT/OpenCR-Binaries/raw/master/turtlebot3/ROS1/latest/opencr_update.tar.bz2 && tar -xvf opencr_update.tar.bz2 && cd ./opencr_update && ./update.sh $OPENCR_PORT OPENCR_MODEL.opencr && cd ..

３接通电源时动不了

问题：没有用电池而是接电源时移动不了

解决方法：用电池

４开始还能动，后面就报以下错误了

roslaunch turtlebot3_bringup turtlebot3_robot.launch

ERROR: cannot launch node of type [hls_lfcd_lds_driver/hlds_laser_publisher]: hls_lfcd_lds_driver

解决方法

turtlebot3启动 roslaunch turtlebot3_bringup turtlebot3_robot.launch