PRH-RRT*

Potential Functions and Receding Horizon-based RRT*
Local path planning algorithm for real-time navigation in dynamic environments.

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Overview

This repository provides an implementation of PRH-RRT*, an extension of the RRT* (Rapidly-exploring Random Tree Star) algorithm designed for real-time local path planning in cluttered and dynamic environments.

PRH-RRT* enhances classical RRT* by introducing:

• Receding-horizon-based tree management to limit computation to a moving region around the robot.
• Potential-function-based tree biasing to guide exploration toward the global path while maintaining obstacle clearance.
• Online tree trimming to remove outdated or collision-prone branches as the robot moves.

The algorithm is intended for mobile robot navigation and has been validated in realistic simulation environments.

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Key Features

• Local path planning with receding horizon strategy
• Potential-field-guided tree expansion (attractive, repulsive, and exploratory terms)
• Real-time tree pruning for computational efficiency
• Compatible with ROS-based simulation and mapping frameworks
• Designed for dynamic and partially observable environments

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Dependencies

The following open-source packages were used to run and evaluate PRH-RRT*:

• AWS RoboMaker Hospital World
  https://github.com/aws-robotics/aws-robomaker-hospital-world

• Rover Robotics ROS1 Stack
  https://github.com/RoverRobotics/roverrobotics_ros1

• OctoMap Mapping
  https://github.com/OctoMap/octomap_mapping

Additional requirements:

• ROS1 (tested with Noetic)
• C++14 / Python3
• Numpy
• Pandas

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Installation

1. Clone the Repository

git clone https://github.com/ziuoo/PRH-RRT_star.git
cd PRH-RRT_star

2. Install Dependencies

rosdep update
rosdep install --from-paths src --ignore-src -r -y

3. Build the Workspace

catkin_make # or catkin build
source devel/setup.bash

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Usage

Launch Simulation Environment

Example using AWS RoboMaker Hospital World:

roslaunch mission_controller hospital_simulation.launch

Run PRH-RRT* Planner

roslaunch prh_rrt_star prh_rrt_star.launch

The planner subscribes to local map and robot state topics and publishes a collision-free local path in real time.

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Repository Structure

PRH-RRT_star/
├── prh_rrt_star/            # Core PRH-RRT* planner implementation
│   ├── src/                 # Algorithm source code
│   └── launch/              # ROS launch files
├── pkgs_localmap/           # Local occupancy and OctoMap integration
├── pkgs_simul/              # Simulation-related packages
├── mission_controller/      # Mission and execution management
├── CMakeLists.txt
└── README.md

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Notes

• This repository focuses on local planning; a global path is assumed to be provided by an external planner.
• Dynamic obstacles are handled in an observation-driven manner using updated occupancy information.
• Parameter values were empirically tuned through simulation experiments.