High Speed Stereovision Setup for Position and Motion Estimation of Fertilizer Particles Leaving a Centrifugal Spreader

Abstract

A 3D imaging technique using a high speed binocular stereovision system was developed in combination with corresponding image processing algorithms for accurate determination of the parameters of particles leaving the spinning disks of centrifugal fertilizer spreaders. Validation of the stereo-matching algorithm using a virtual 3D stereovision simulator indicated an error of less than 2 pixels for 90% of the particles. The setup was validated using the cylindrical spread pattern of an experimental spreader. A 2D correlation coefficient of 90% and a Relative Error of 27% was found between the experimental results and the (simulated) spread pattern obtained with the developed setup. In combination with a ballistic flight model, the developed image acquisition and processing algorithms can enable fast determination and evaluation of the spread pattern which can be used as a tool for spreader design and precise machine calibration.

Precision Agriculture Technologies Positively Contributing to GHG Emissions Mitigation, Farm Productivity and Economics

“…VRNA is executed by either applying a prescription map that was designed after receiving data from the field using mainly canopy sensors that identify the status of the crop and correlate it with nutrient needs or by combining the recording and reacting procedure on-the-go, meaning simultaneously inorganic fertilizers are distributed in the field using two main technologies, the spinner or centrifugal spreaders that are based on a conveyer belt or chain that transfers the material (granules) from the hopper until it falls on one or more spinning disks throwing the particles into the field and the pneumatic spreaders that use airflow which divides the granules over a piped spreading boom for uniform distribution [40,41]. In VRNA through spinner spreaders, the application rate is controlled by adjusting the gate opening and/or changing the speed of the conveyor (and thus the input rate of material).…”

Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles

“…High intensity is necessary to maximize the depth of field and minimize motion blur. However, uniformity is also important to reduce under-segmentation and increase the accuracy of the matching steps [13]. To deal with these two optimization problems, a multiple objective optimization was used.…”

“…Moreover, application is limited to spreading disks with straight vanes assuming that particles slide along the disk. Hijazi et al developed a high speed stereo image acquisition system to counter these problems [13]. As in the studies of [11,14], a field of view of 1 m × 1 m was used to capture full throws of fertilizer in one image.…”

“…Therefore, this paper deals with the development of a lighting system to provide these specific requirements. In future work, the developed lighting system will be used in combination with a stereovision setup and motion estimation algorithms (see [13]) to determine accurately the spread pattern of centrifugal fertilizer spreaders.…”

Method for Volume of Irregular Shape Pellets Estimation Using 2D Imaging Measurement

“…With increasing productivity, the best tools for quality assurance are indirect methods of measuring that allow real-time evaluation of the quality of pellets [1][2][3][4][5][6][7][8][9][10][11][12][13]. The technique of processing digital images provides results that are very similar to the results of control equipment based on direct measurements [14][15][16][17][18][19].…”