followbot: A Python repository from davidlee1435

Lab 5

David Lee (jl4397) Rachel Wu (rww2115)

COMSW4733 Computational Aspects of Robotics
Peter Allen

Unzip tarball and cd into this repository

$ cd <path_to_this_repo>

In one terminal run the world file. To launch turtlebot and map for part 1

roslaunch followbot launch.launch

To launch turtlebot and map for part 2

ROBOT_INITIAL_POSE="-x -2.85 -y -0.27 -Y 1.53" roslaunch followbot launch.launch world_file:=color.world

To launch turtlebot and map for part 3

ROBOT_INITIAL_POSE="-x -2.85 -y -0.27 -Y 1.53" roslaunch followbot launch.launch world_file:=shape.world

To launch the map for extra credit

ROBOT_INITIAL_POSE="-x -2.85 -y -0.27 -Y 1.53" roslaunch followbot launch.launch world_file:=extra.world

In another terminal, run the script in the src directory.

For part 1: python p1.py
For part 2: python p2.py

Part 1 p1.py

Follower: class that provides logic for the bot's movements
image_callback(): Callback passed into the image subscriber. Creates a binary mask based on the robot's camera's input and follows the line that the mask forms.

Part 2 p2.py

Follower: class that provides logic for the bot's movements. Initialized with several values corresponding to the lower and upper HSV bounds for the colors on the map
get_mask_for_color(): given an HSV frame and a color, this function returns 20 pixels of what the robot sees masked with the color. If, for example, 'red' is passed in as an argument, the resulting image would show white for a pixel if that pixel was red in the original image.
rotate(): rotates the bot
image_callback(): the image callback function passed into the imag subscriber. For every frame, it checks if the centroid of the mass of colored pixels is a red, blue, green, or yellow pixel in the original image. It turns left if the pixel is green, right if the pixel is blue, stops if the pixel is red, and follows the line if the pixel is yellow.