by, Israel Raul Tiñini Alvarez and Ruben Coarecona
Instructor: Ing. Pinaya Gutierrez Benjamin
The objective of this project is to implement a navigation system based on ROS for the control of a terrestrial robot that performs autonomous localization and navigation tasks.
A simulated differential vehicle model was created that satisfies the necessary requirements: the transformation tree, the odometry, the laser scanner and the base controller, whose code can be found in the folder src/mybot_description/mybot.xacro
Gmapping, mapserver and teleoperation were used to map the simulated environment in Gazebo, for this three steps were followed: create the map, save the map and load the map. The maps are in src/mybot_navigation/maps and the worlds of Gazebo are in src/mybot_gazebo/world
In the simulation of the autonomous navigation of the robot, ACML was used for the location and the base move package for navigation, in addition to the simulated model of the robot that was charged in Gazebo to perform the simulation, the parameters of the navigation node were configured find in src/mybot_navigation/config
A differential vehicle was built, which was composed mainly of two engines, an arduino and a raspberry pi 3B, and autonomous navigation was carried out with this. Autonomous navigation of a simulated and physical land vehicle could be performed, however the evasion of obstacles I just managed to make it through the simulation. For the detection of physical osbtaculos Visp_auto_track was used, because this uses the node of usb_cam which is compatible with the Raspberry
There are basically three steps:
- Creating the map
- Saving the map
- Loading the map.
Run the following commands below. Use gmapping to map the environment, acml for localitation, the teleop to move the robot around to create an accurate and thorough map:
- Launch the Gazebo world
roslaunch mybot_gazebo mybot_world.launch - Start map building
roslaunch mybot_navigation gmapping_demo.launch - Launch RVIZ
roslaunch mybot_description mybot_rviz_gmapping.launch - Start teleop
roslaunch mybot_navigation mybot_teleop.launch
Run the following commands below. Use MapServer to save the map.
- Save the map using MapServer
rosrun map_server map_saver -f ~/mybot_ws/src/mybot_navigation/maps/test_map
Run the following commands below. Verify that the mapping was done well
- Launch the World
roslaunch mybot_gazebo mybot_world.launch - Load the map
roslaunch mybot_navigation amcl_demo.launch
Run the following commands below. Use rviz to set navigation waypoints and the robot should move autonomously
- Launch the World
roslaunch mybot_gazebo mybot_world.launch - Load the map
roslaunch mybot_navigation amcl_demo.launch - Launch RVIZ
roslaunch mybot_description mybot_rviz_amcl.launch
SIMULATE AUTONOMOUS NAVIGATION VIDEO
Run the following commands below.
- Start serial communication (Raspberry)
rosrun rosserial_python serial_node.py /dev/ttyACM0 - Launch the World
roslaunch mybot_gazebo mybot_world.launch - Launch the teleoperation
roslaunch mybot_navigation mybot_teleop.launch - Start the node that transforms speed messages
rosrun odometria twist_to_motor - Start the node that transforms the count of the encoders into a odometry message
rosrun odometria diff_tf - Listen to the speed in PWM of the engine 1
rostopic echo /motor1 - Listen to the speed in PWM of the engine 2
rostopic echo /motor2
Run the following commands below.
- Start serial communication (Raspberry)
rosrun rosserial_python serial_node.py /dev/ttyACM0 - Start the node that transforms the count of the encoders into a odometry message
rosrun odometria diff_tf - Start the node that transforms speed messages
rosrun odometria twist_to_motor - Launch the Move Base node with ACML
roslaunch mybot_navigation amcl_demo.launch - Launch RVIZ
roslaunch mybot_description mybot_rviz_amcl.launch - Listen to the speed in PWM of the engine 1
rostopic echo /motor1 - Listen to the speed in PWM of the engine 2
rostopic echo /motor2