An aerial robotic system for inventory of stockpile warehouses

Abstract

This article describes the development and evaluation of an aerial robotic system for smart inventory of stockpile warehouses. The system was developed to automatically measure piles of different bulk materials, such as phosphorus and potassium compounds, which are stored in bays of different sizes inside a warehouse. This warehouse configuration is very common among fertilizer and animal food industries in Brazil. While an inventory can be executed by a human technician, the insalubrious environment, the imprecision of the manual volume estimation, and the time spent by the technician to access the information motivate the automation of the process. The proposed system uses a multirotor electrical drone that navigates autonomously inside the warehouse while it acquires light detection and ranging (LIDAR) point cloud data. This data is used to build a three-dimensional (3D) model of the environment, which is then processed to identify the stockpiles of material and calculate their volumes.Since the environment is GPS-denied and its characteristics, including symmetry, illumination and texture, do not favor visual-or LIDAR-based localization, a drone navigation strategy that relies on relative positioning with respect to simple structures of the warehouse was developed. This article also presents our approach for autonomous stockpile volume estimation, which was numerically evaluated both in simulation and with real data, yielding in accuracy and precision of about 98%. The results presented in the article show that the aerial system is able to substitute the previously adopted manual procedure, highly increasing its accuracy, repeatably and safety, and drastically reducing its time of execution and cost.

A Novel Multi-LiDAR-Based Point Cloud Stitching Method Based on a Constrained Particle Filter

“…Drone scanning involves the use of unmanned aerial vehicles (UAVs) equipped with cameras or laser scanners to perform aerial scans of coal piles [8][9][10][11]. This system can rapidly capture surface data of extensive coal piles within a short timeframe, thereby offering the advantages of improved resolution and comprehensiveness.…”

Design and development of an autonomous unmanned aerial vehicle for surface coalmines surveillance

“…This study aimed to examine the accuracy of measuring stockpile volumes using UAVs. The objectives of the research were to assess errors in field measurements and high-precision volume calculations, to map the volume of stockpiles [19] using UAV images, and to calculate the time needed for the survey. The imaging process was performed using a UAV, while the detailed survey was carried out through Laser Scanning to compare and verify the accuracy of both methods.…”

Stockpile Volume Estimation in Open and Confined Environments: A Review

“…Recently, multirotor drones have been employed in numerous applications involving confined space inspection, including stockpile volume estimation, e.g., [1,97,98]. Multirotor drones, in particular, possess the ability to hover and fly in all directions, making them well-suited for indoor missions.…”

“…This is besides the fact that vision-based approaches are not favored in dark environments. Gago et al [98] demonstrated the development and evaluation of an aerial robotic system for stockpile volume estimation within warehouses. They used a DJI Matrice 100 quadrotor drone and equipped it with a 3D LiDAR (Velodyne VLP 16 Puck Lite).…”