Slam mapping, automatic navigation and obstacle avoidance based on ROS (bingda robot)

SLAM yes Simultaneous localization and mapping abbreviation , Meaning for “ Synchronous positioning and mapping ”, It is mainly used to solve the problem of localization and map construction when the robot moves in unknown environment . The robot moves from an unknown position in an unknown environment , Position yourself according to the location and map during the movement , At the same time, build incremental maps on the basis of their own positioning , Realize autonomous positioning and navigation of robot .

The trolley can run ros Lidar function pack , stay PC Terminal rviz Can be viewed in ; Starting the chassis 、 After keyboard control, the trolley can be controlled to move ; according to SLAM The algorithm maps the laboratory environment ; It can be saved 、 Read the map , stay PC End control trolley from A Point to B Point to achieve path planning and automatic obstacle avoidance .

This paper takes bingda robot car as an example , Some problems have been encountered in actual use , A more detailed tutorial summarized .

software platform ：Linux（Ubuntu18.04.6）.

Hardware platform ： Bingda robot .

Language version ：Python 2.7

One . install ROS And configuration environment

1.ROS install

I recommend using the one click installation of Xiaoyu , Can solve 99% The problem of

One click installation instruction ：

wget http://fishros.com/install -O fishros && . fishros

Official website ： Home page | Fish fragrance ROS（ But teaching is ROS2 Mainly , Bingda robot can only use ROS1）
Open source address ：https://github.com/fishros/install

2. Work area installation

First of all, from the git Download the required feature pack to your workspace , We still use catkin_ws Take a workspace as an example

mkdir -p  ~/catkin_ws/src/
cd ~/catkin_ws/src/
git clone https://gitee.com/bingda-robot/base_control.git
git clone https://gitee.com/bingda-robot/lidar.git
git clone https://gitee.com/bingda-robot/robot_vision.git
git clone https://gitee.com/bingda-robot/robot_navigation.git
git clone https://gitee.com/bingda-robot/robot_simulation.git

Compile the workspace after pulling

cd ~/catkin_ws/
catkin_make

Then we will solve the function package dependency
If your rosdep It can be used normally. （ It can be used normally according to this tutorial ）, So you can go through rosdep To check whether all the dependent packages meet

cd ~/catkin_ws/
rosdep check --from-path src

If the result of execution is “All system dependencies have been satisfied”, Then all dependent items have met , No installation required
otherwise , Then execute the following instructions to install the dependent packages

rosdep install --from-path src -y

If your rosdep Not working properly , Then you can install it manually by installing the dependency list provided by us

sudo apt-get update
sudo apt-get install ros-$ROS_DISTRO-teleop-twist-keyboard ros-$ROS_DISTRO-amcl ros-$ROS_DISTRO-move-base ros-$ROS_DISTRO-slam-gmapping ros-$ROS_DISTRO-slam-karto ros-$ROS_DISTRO-cartographer ros-$ROS_DISTRO-cartographer-ros ros-$ROS_DISTRO-dwa-local-planner ros-$ROS_DISTRO-teb-local-planner ros-$ROS_DISTRO-uvc-camera ros-$ROS_DISTRO-map-server ros-$ROS_DISTRO-hector-slam* ros-$ROS_DISTRO-global-planner ros-$ROS_DISTRO-navfn -y

Set the environment variable

cd /catkin_ws/devel
source setup.bash

Two . Configure distributed

1. Connecting robots ：ssh [email protected]
2. Open the virtual machine terminal input ,ifconfig see Ubuntu Of IP Address , Let the two machines interact ping, Make sure you can receive data .
3. stay PC End Input gedit .bashrc Yes .bashrc Make changes （ name 、 robot ip）, Add relevant information , As shown in the figure below .

   

     chart 1 .bashrc New contents of the document

3、 ... and . Synchronize trolley time

. because robot No power-off protection , So after every shutdown and restart , Its time cannot correspond to the real time , And ours pc Is able to connect to the Internet , Can pass ntp Server time calibration
If in the experiment pc No extranet environment , Help first pc Get an Internet environment , Then install a ntp The server ：

[email protected]:sudo apt install ntp

Take us pc Think of it as a ntp The server ,robot According to pc Do your own time calibration ：

[email protected]:sudo ntpdate 192.168.x.x // Everyone's computer assigned ip Different , Here with their own pc Of ip Subject to 

If you find that robot Unable to get pc Time calibration , Then calibrate the time manually ：

[email protected]:sudo date --s=" 2022-06-21 11:12:00"

Four . Start the lidar

1. Start the lidar ：

[email protected]:roslaunch robot_navigation lidar.launch

1. View published topics , Looking for radar ：

[email protected]:rostopic list  

3. Print radar scanned data :

[email protected]:rostopic echo /scan

4.pc: use rviz Look at the image :

[email protected]:roslaunch robot_navigation lidar_rviz.launch

chart 2 Run lidar

5、 ... and . Run lidar and laser SLAM Drawing

1. Run lidar ：

[email protected]:roslaunch robot_navigation robot_slam_laser.launch

2. Start the chassis ：

[email protected]:roslaunch base_control base_control.launch

3. Activate keyboard control ：

rosrun teleop_twist_keyboard teleop_twist_keyboard.py

4. use rviz Look at the image ：

[email protected]:roslaunch robot_navigation slam_rviz.launch

5. View map file :

[email protected]:roscd robot_navigation/maps

6. preservation map：

[email protected]:rosrun map_server map_saver -f map

chart 3 Saved map and nodes

6、 ... and . Run lidar and obstacle avoidance

1. Run lidar to avoid obstacles （ Will read the previously saved map ）：

[email protected]:roslaunch robot_navigation robot_navigation.launch

2. use rviz see ：

[email protected]:roslaunch robot_navigation navigation_rviz.launch

3. use 2D Pose Estimate Change the initial test position , Make the radar range of the car basically consistent with the previously saved map .

4. use 2D Nav Goal Point to our destination , The trolley will automatically plan the path and drive to the target point .

chart 4  Read the map

  chart 5  Path planning

7、 ... and . Other questions

1. No map data

Check the distributed configuration （ mutual ping）;

Check Python edition , It must be Python2.

2.xxx is neither a launch file in package nor xxx is a launch file name

The workspace environment was not added to .bashrc, Or go to the workspace directory before each run source once .

This article only represents personal views , If there is a mistake , I hope readers can point out .