Sub-Optimal-Path-Finder

Overview

This project implements search-based algorithms that yield a sub-optimal path if one exists. Path finding algorithms, such as Weighted A*, have been used to find a sub-optimal path for the robot from the user-defined start to end point. The project also generates animation to visualize the exploration of each of the mentioned search-based methods. It first checks that the user inputs do not lie in the obstacle space. Note that the obstacle space is pre-defined and static.

In Weighted A*, the heuristic cost is multiplied by an inflation factor, epsilon. If epsilon is 1, Weighted A* reduces to A*.

Unlike A* and Weighted A*, Depth-first search(DFS) has no concept of cost-to-come and cost-to-goal. Moreover, it is based on a Last-In-First-Out (LIFO) queue. A LIFO queue is simply known as a stack.

Figure 1 - Comparison of A*, Weighted A*, and DFS

Todo

• Implement tree based algorithms such as PRM and RRT

Dependencies

• Python3
• Python3 Libraries: Numpy, OpenCV-Python, Math, Queue, Time, Sys, Ast

Install Dependencies

• Install Python3, Python3-tk, and the necessary libraries: (if not already installed)

These commands are based for Linux systems such as Ubuntu
sudo apt install python3
sudo apt install python3-pip
pip3 install numpy opencv-python queue

• Check if your system successfully installed all the dependencies
• Open terminal using Ctrl+Alt+T and enter python3
• The terminal should now present a new area represented by >>> to enter python commands
• Now use the following commands to check libraries: (Exit python window using Ctrl+Z if an error pops up while running the below commands)

import numpy
import cv2
import queue

Run

• Using the terminal, clone this repository and go into the project directory, and run the main program:

git clone https://github.com/urastogi885/sub-optimal-path-finder
cd sub-optimal-path-finder

• If you have a compressed version of the project, extract it, go into project directory, open the terminal, and run the robot explorer.

python3 robot_explorer.py <start_x,start_y> <goal_x,goal_y> <robot_radius> <clearance> <method> <animation>

• An example for using Weighted A* for a rigid robot:

python3 robot_explorer.py 50,30 150,150 2 1 0 1

• The output in the Overview section has been generated using the above arguments.