Research Track 1 - Assignment 2 - Solution

This is yet another simple and portable robot simulator which runs in a circuit. The requirements of the assignment are by using ROS and C++,

• to make robot move autonomously in the circuit as in the first assignment,
• to have a node to control the robot, and an additional node to interact with user to increase/decrease of the robot speed and reset position.

Installing and running

Choose a directory to work in, then clone the repo by typing

git clone https://github.com/EbruBaglan/secondassignment01

After you download and build the workspace, first initialize roscore by hitting,

$ roscore &

then go to the main directory on package and just hit

$ ./runew.sh

The simulation environment and all the nodes within are initiated just by that.

You will be at the user interface asking for increase/decrease/reset command.

Here is the video for run and proof that code works: https://youtu.be/xC3xZsW8AZs

Structure

There are 2 nodes to assure communication. userinterface node asks user for input, controller node provides both autonomous movement, and user-input movement.

There is one service. service service has the structure of char request and float32 response. Response is the increase/decrease value to the velocity.

How it works?

Automous moving part is straighforward. As long as there is no obstacle in front, robot keeps moving. When the front distance lowers to a certain distance, robot checks right and left surroundings. Whichever side is the farthest, robots turns toward that direction.

When user inputs a value, userinterface calls the service with the request char. Controller node, checks the request in the service structure, and puts an increment/decrement response into service, and it itself uses it in linear.x velocity assignment, and publishes it into cmd_vel.

Flowchart