In a typical stockpile measurement scenario, calculating volumes with a drone came within 95% of a laser scanner output with 96% time savings on field data collection. For this customer, adopting drones for regular stockpile measurement led to cost savings of up to 30% and improved operational efficiency.
A large aggregate company sells asphalt and readymix cement to clients all over the United States. As their Bay Area site has grown, their incoming daily orders require more raw materials than can be delivered each morning. To keep up with demand, they need to stockpile material and accurately measure and record all materials available on any given day. The estimate the benefit to more frequent and accurate stockpile measurement will be:
Cost Savings: Previously this aggregate company paid for materials by the truckload (one truck = 24 tons). This meant that they risked being overbilled for trucks arriving with material under capacity and overpaying for materials, like sand, that often arrive wet. The company estimated they could be paying up to 30% more than expected for raw materials.
Operational Efficiency: Relying on calculating volume by counting trucks coming and going leaves a large margin of error (30-40%) and hurts their ability to deliver the accurate amount of material to customers at the right time.
Field Data Collection:
Laser Scanning (81 minutes)
Stockpiles were first measured with a high-end 3D laser scanner to achieve the best possible accuracy.
Nine scans were completed on two medium stockpiles. Each scan took approximately 9 minutes, resulting in 81 total minutes in the field.
Operations were suspended while the site was scanned.
Drone (3 minutes)
Flight was planned and autonomous drone was flown using 3DR Site Scan.
One flight was conducted over the two medium stockpiles (approximately 15% of total battery).
Flight was completed in three minutes.
Data stored on the scanner is transferred to Autodesk ReCap.
In ReCap data is manually calibrated, and RCMs are exported.
RCMs are imported to ReMake to calculate volumes.
Imagery is sent for cloud processing from the field.
RCMs are downloaded from 3DR web application.
RCMs are imported into ReMake to calculate volumes.
Total volume measured with the laser scanner was 425.7m3 vs. 404.6 m3 from the drone, a difference of 5%. Given the minimal time for data collection and expected cost savings and efficiency gains, the supervisor of the aggregate site plans to deliver a weekly report with accurate volume measurements.