P-PUMA Control System

A ROS 2 C++ package implementing advanced path tracking control algorithms for autonomous vehicle guidance. The system provides multiple pursuit-based strategies (Pure Pursuit, LP Pursuit, ACC Pursuit) with configurable vehicle dynamics models.

Overview

The P-PUMA control system is designed to guide autonomous vehicles along predefined paths using interchangable path-tracking algorithms. It integrates with ROS 2 for distributed computing and real-time control, offering flexible algorithm selection and tunable parameters for different vehicle configurations and driving conditions.

Features

• Multiple Path Tracking Algorithms

  • Pure Pursuit: Classic pursuit algorithm for smooth path tracking
  • LP Pursuit: Low-Pass filtered pursuit for reduced steering noise
  • ACC Pursuit: Acceleration-based pursuit strategy + Low-Pass filtering

• Vehicle Dynamics Models

  • Dry surface dynamics
  • Wet surface dynamics
  • Configurable via VehicleConfig Class

• Robust Control

  • Mission-based speed limits
  • State validation and timeout detection
  • Emergency handling

Project Structure

p-puma/
├── control_p2/                  # Main ROS 2 package
│   ├── include/control_p2/
│   │   ├── control_manager.hpp      # Core control logic management
│   │   ├── control_node.hpp         # ROS 2 node implementation
│   │   ├── options.hpp              # Configuration parameters
│   │   ├── utils.hpp                # Utility functions
│   │   ├── math/
│   │   │   ├── pure_pursuit.hpp
│   │   │   ├── lp_pursuit.hpp
│   │   │   └── acc_pursuit.hpp
│   │   └── model/
│   │       ├── vehicle_config.hpp
│   │       └── dry_model.hpp
│   ├── src/
│   │   ├── control_manager.cpp
│   │   ├── control_node.cpp
│   │   └── math/
│   │       ├── pure_pursuit.cpp
│   │       ├── lp_pursuit.cpp
│   │       └── acc_pursuit.cpp
│   ├── CMakeLists.txt
│   ├── package.xml
│   └── LICENSE
├── test/                        # Unit tests
│   ├── test_manager.cpp
│   └── test_plan.cpp
├── doc/                         # Documentation/Images    
└── README.md

Dependencies

Core Dependencies

• ROS 2 (Humble or newer recommended)
• ament_cmake: Build system
• rclcpp: ROS 2 C++ client library
• Eigen: Linear algebra library
• lart_msgs: Custom message definitions (LART project)
• tf2: Coordinate transformation library

Installation

Prerequisites

Ensure you have ROS 2 installed and sourced:

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

Build from Source

# Clone the repository
cd ~/ros2_ws/src
git clone https://github.com/yourusername/p-puma.git

# Build the package
cd ~/ros2_ws
colcon build --packages-select p-puma

# Source the workspace
source install/setup.bash

Usage

Launch the Control Node

ros2 run p-puma control_p2

ROS 2 Topics

Subscriptions (Inputs)

Topic	Message Type	Description
/lart/state	lart_msgs/State	Current vehicle state
/lart/mission	lart_msgs/Mission	Mission configuration
/lart/path	lart_msgs/PathSpline	Path to follow
/lart/dynamics	lart_msgs/Dynamics	Vehicle dynamics parameters
/pose	geometry_msgs/PoseStamped	Current vehicle pose

Publications (Outputs)

Topic	Message Type	Description
/lart/dynamics_cmd	lart_msgs/DynamicsCMD	Control commands (speed, steering)
/visualization_marker	visualization_msgs/Marker	Visualization of target point

Configuration

Algorithm Selection

Edit control_p2/include/control_p2/options.hpp:

#define ALGORITHM  "math/lp_pursuit.hpp"
#define MODEL      "model/dry_model.hpp"

Available algorithms:

• math/pure_pursuit.hpp
• math/lp_pursuit.hpp
• math/acc_pursuit.hpp

Speed Limits

Configure mission-based speed limits in options.hpp:

#define DEFAULT_MAX_SPEED 2.0f  // m/s
#define ACC_SPEED 2.0f          // m/s
#define EBS_SPEED 2.0f          // m/s

Control Frequency

#define FREQUENCY 50  // Hz

Algorithm Details

Pure Pursuit

• Classic path-tracking algorithm

LP Pursuit (Low-Pass)

• Enhanced Pure Pursuit with filtered steering
• Reduces high-frequency steering noise
• Smoother vehicle response

ACC Pursuit (Acceleration Control)

• Combines low-pass path tracking with speed regulation
• PID-based speed controller

Testing

Run unit tests:

colcon test --packages-select p-puma

Acknowledgments

• Built for LART (Leiria Academic Racing Team)

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Last Updated: March 2024
ROS 2 Version: Humble (or newer)
Build Status: