41014_SLAMTurtlebot

READ ME FOR CODE ONLY

Currently Implemented on Turtlebot:

Follow the right side wall and maneuver from straight ahead wall with a simple algorithm
Update the subscribed data (current odometry, LiDAR scans) from ROS and assign to global variables
Process LiDAR reading to determine wall avoiding logic
Build structure for code and internal commands for specific Turtlebot's action
Block function built for update and no need to rebuild
Complete basic Mapping of a customised floor plan constructed in Gazebo

To Do (Future Work):

Escape from Collision
Complete exit from Collision and return to Go Ahead
Can get through a small hole because SLAM detect is noisy
Deal with real problem when real LIDAR is interfered by material
Detect the chosen target/position _____________________________________________________________________________|

How to apply the code

1. Prerequisites 
- Before starting ROS, make sure the IP address is up to date
- Command:
	+ $ ifconfig (Find the assigned IP address)
	+ $ nano ~/.bashrc (Open and update ROS IP)
	+ $ source ~/.bashrc (Source the bashrc)

2. Start ROS
- Command:
	+ $ roscore


3. Start Gazebo	
- Command 
	+ $ roslaunch turtlebot3_gazebo turtlebot3_empty_world.launch
- Manual input the mapp
	+File MAP A2
	
4. Start RVIZ (SLAM)
- Command:
	+ $ roslaunch turtlebot3_slam turtlebot3_slam.launch slam_methods:=gmapping
	or
	+ $ roslaunch turtlebot3_slam turtlebot3_slam.launch
5. Running CODE in the IDE platform (VScode)
	Ctrl + C when Mapping is completed

6. Save Map
-Command:
	+ $ rosrun map_server map_saver -f ~/map

7. Turn off the RVIZ SLAM and start RVIZ NAVI
-Command:
	+ $ roslaunch turtlebot3_navigation turtlebot3_navigation.launch map_file:=$HOME/map.yaml

Individual Contributions

Actually, we have worked together and we all understand the code, algorithm, structure... so individual work is quite hard to determine. But basiclly, Khanh worked on calibration the most, Nam focused on the flow of data and Trung tried to build the structure.

Then, DIEN TRANG KHANH 30%, NAM VU 35%, TRUNG LE 35% for the coding only.

Progress Reports (CODE ONLY);

13/10/22 ALL TEAMS

Divide code for simulation and real Demo
- CODE for simulation: DONE
- CODE for real Demo: Working....
Find shortest path code (not the priority then using RVIZ packages)
Delete Update nav_msgs.msg/ Path

............................................................................. 12/10/22 Nam Vu and Trung Le

testing code and debug
Update nav_msgs.msg/ Path
Update logger and loginfor

Trang Khanh Dien

Do Calibration for Laser Scan ............................................................................. 5/10/22
Working on the Algorithms CODE LOGIC: ALGORITHM UPDATE CURRENT CHOICE CHOICE RETURN NEXT STATE RESET DATA ............................................................................. 4/10/22 TRANG KHANH DIEN
Update Callback Callback for Laser Returns the range value of LiDAR Callback for Odometry Returns the value of global x and yaw

4/10/22 TRUNG LE

Add rate sleep to the command
When Turtlebot3 rotates, LaserScan is still active and interrupts rotation
Update code: If (abs(current yaw - initial yaw) < pi/2) #Done turn rate.sleep()

4/10/22 NAM VU

Updated orientation commands
Rebuild flow code:

Main: STATE (1 -> 6) CALLBACK() ALGORITHM UPDATE CURRENT CHOICE CHOICE RETURN NEXT STATE EACH STATE: DO 1 COMMAND

............................................................................. 21/9/22 TRUNG LE

Update Structure for code Structure 1: State { Go Ahead Turn Left Turn Right Check Collision Go Ahead while turn left Go Ahead while turn right }
Each State will be executed with different sets of commands, avoiding duplicate orders
Updated Structure for laser data Structure 2: Laser { Angle 0 Angle from 30 to 60 ... }

............................................................................. 20/9/22 TRANG KHANH DIEN

Build minimun range for Lidar, want to use PID control so lidar will be projected at angles of 30-60 for right and 300-330 for left.
Update, no using PID
Subscribe to LaserScan can scan data in 1 area min range [30:60] (Wall Follow) min range [0:15] && [345:359] (Ahead)

............................................................................. 16/9/22: NAM VU

Update functions to use +Function (Move or Turn or Check) Declare global variable linear angular return globle variable
Test the Functions. The functione inear = 1 angular = 0 current_choice = 2 (Turn) linear = 0 angular = 1 (-1)

............................................................................. 11/9/22: TRUNG LE

Use Rosmsg and Rostopic to identify topics suitable for programming. Select topic /cmd_vel (Twist()) as the main topic for moving the robot.
Logic Code:
- Go Ahead (Pub in linear.x) and current distance (Sub in Odemetry) if current distance < distance (min distrance with wall) Turn Left

11/9/22: TRANG KHANH DIEN

Identify other Topics to subscribe to:
- sensor_msgs/LaserScan
- nav_msgs/Odometry
- Math
- Transformation
Instead of determining the distance by a certain value, we can determine it by subscribing to the data in LaserScan.
Logic Code:
- If LaserScan < minimum variables Turn

............................................................................. 10/9/22: NAM VU 1.

Install packages (Gazebo, SLAM, Turtlebot3 Empty World,...) to prepare the code.