ROS Robot Simulation

======================= Reaserch Track1, 2nd assignment Professor: Carmine Recchiuto Student: Shima Amiri Fard

Installing & Running:

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to build the program, run the following commands:

$ mkdir -p catkin_ws/src

$ cd catkin_ws/src

$ git clone https://github.com/shimaamiri/ResearchTrack_assignment2.git

$ cd ..

$ source /opt/ros/<distro>/setup.bash

$ catkin_make

To run the programm, open 4 terminals and run one of the following commands in each of them:

$ roscore

$ rosrun stage_ros stageros $(rospack find second_assignment)/world/my_world.world

$ rosrun second_assignment controller

$ rosrun second_assignment UI

Problem & Solution:

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The robot endowed with laser scanners, should move inside a circuit with the possibility to increase/decrease the velocity or reset the position by user. This program consists of the following components:

• Stageros node from the world folder, which consists of the simulation environment (robot and robot circuit).
• User interface (UI) node, which interacts with the user (increase / decrease the speed or reset the robot’s position).
• Controller node, for controlling the robot.
• A Service, which takes as the request the user command and gives as the responce the velocity.

• For obtaining the distance from the wall, the ranges vector of laser scanner should be considered (we divide the ranges vector into 3 subsections; left, front, and right. Then, we consider the minimum value of each subsection, which provides information about the closest wall).

The program rosgraph is shown in the following image:

Controller node

Subscribes to command and base_scan topics and publishes the robot control signal with respect to detected obstacles to cmd_vel topic.

User Interface (UI) node

Recieves as input the increasing/decreasing speed command or reset position request from the user and publishes them on command topic.

Flowchart

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The program flowchart is shown in the following image: