PiLiDAR is a project demonstrating a low-cost, DIY LiDAR scanner built using a Raspberry Pi. It leverages a readily available RPLiDAR A1M8 sensor, Python code, and a simple mechanical setup involving a servo motor to rotate the LiDAR unit, creating 360-degree scans. The project provides complete instructions and software, allowing users to easily build their own LiDAR system for applications like robotics, mapping, and 3D scanning. The provided Python scripts handle data acquisition, processing, and visualization, outputting point cloud data that can be further analyzed or used with other software.
This paper explores the feasibility of using celestial navigation as a backup or primary navigation system for drones. Researchers developed an algorithm that identifies stars in daytime images captured by a drone-mounted camera, using a star catalog and sun position information. By matching observed star positions with known celestial coordinates, the algorithm estimates the drone's attitude. Experimental results using real-world flight data demonstrated the system's ability to determine attitude with reasonable accuracy, suggesting potential for celestial navigation as a reliable, independent navigation solution for drones, particularly in GPS-denied environments.
HN users discussed the practicality and novelty of the drone celestial navigation system described in the linked paper. Some questioned its robustness against cloud cover and the computational requirements for image processing on a drone. Others highlighted the potential for backup navigation in GPS-denied environments, particularly for military applications. Several commenters debated the actual novelty, pointing to existing star trackers and sextants used in maritime navigation, suggesting the drone implementation is more of an adaptation than a groundbreaking invention. The feasibility of achieving the claimed accuracy with the relatively small aperture of a drone-mounted camera was also a point of contention. Finally, there was discussion about alternative solutions like inertial navigation systems and the limitations of celestial navigation in certain environments, such as urban canyons.
Summary of Comments ( 158 )
https://news.ycombinator.com/item?id=43738561
Hacker News users discussed the PiLiDAR project with a focus on its practicality and potential applications. Several commenters questioned the effective range and resolution of the lidar given the Raspberry Pi's processing power and the motor's speed, expressing skepticism about its usefulness for anything beyond very short-range scanning. Others were more optimistic, suggesting applications like indoor mapping, robotics projects, and 3D scanning of small objects. The cost-effectiveness of the project compared to dedicated lidar units was also a point of discussion, with some suggesting that readily available and more powerful lidar units might offer better value. A few users highlighted the educational value of the project, particularly for learning about lidar technology and interfacing hardware with the Raspberry Pi.
The Hacker News post titled "Raspberry Pi Lidar Scanner" (linking to a GitHub project called PiLiDAR) has generated several comments, offering a variety of perspectives on the project.
Several users discuss the practicality and applications of such a setup. One user highlights the potential limitations due to the Raspberry Pi's processing power, suggesting that a more powerful platform might be necessary for real-time, high-resolution scanning, especially with more advanced SLAM algorithms. They also express interest in the project's potential for robotics applications. Another user suggests the possibility of using it for indoor mapping and navigation, emphasizing the affordability of the setup. A different commenter points out the previous existence of similar projects using the Raspberry Pi and lidar, indicating this isn't an entirely novel concept.
The discussion also touches upon the specific components used in the project. One comment mentions the RPLidar A1M8, a specific lidar model, and notes its limited range and resolution, suggesting alternative lidar units for improved performance depending on the desired application. This comment thread also delves into the cost-effectiveness of using the RPLidar A1 with a Raspberry Pi, considering other processing options. A separate comment chain discusses the intricacies of processing lidar data on resource-constrained devices like the Raspberry Pi, with suggestions for optimizing code and algorithms.
Some comments focus on the software aspects. One user inquires about the specific SLAM algorithm being used and its suitability for the Raspberry Pi's hardware. Another user expresses interest in the project's potential for creating 3D models of environments. There's also mention of the project's use of Python and its libraries, with some users expressing appreciation for the language choice.
A few comments touch upon the safety aspects of using lidar, particularly regarding eye safety and the power of the laser used.
In summary, the comments section explores various facets of the project, including its technical feasibility, potential applications, component choices, software implementation, and safety considerations. The discussion reveals both enthusiasm for the project's potential and a pragmatic awareness of its limitations.