72 research outputs found
3D Simulation with virtual stereo rig for optimizing centrifugal fertilizer spreading
Stereovision can be used to characterize of the fertilizer centrifugal spreading process and to control the spreading fertilizer distribution pattern on the ground reference. Fertilizer grains, however, resemble each other and the grain images contain little information on texture. Therefore, the accuracy of stereo matching algorithms in literature cannot be used as a reference for stereo images of fertilizer grains.
In order to evaluate stereo matching algorithms applied to images of grains a generator of synthetic stereo particle images is presented in this paper. The particle stereo image generator consists of two main parts: the particle 3D position generator and the virtual stereo rig. The particle 3D position generator uses a simple ballistic flight model and the disc characteristics to simulate the ejection and the displacement of grains. The virtual stereo rig simUlates the stereo acquisition system and generates stereo images, a disparity map and an occlusion map. The results are satisfying and present an accurate reference to evaluate stereo particles matching algorithms
Development of a stereovision-based technique to measure the spread patterns of granular fertilizer spreaders
Centrifugal fertilizer spreaders are by far the most commonly used granular fertilizer spreader type in Europe. Their spread pattern however is error-prone, potentially leading to an undesired distribution of particles in the field and losses out of the field, which is often caused by poor calibration of the spreader for the specific fertilizer used. Due to the large environmental impact of fertilizer use, it is important to optimize the spreading process and minimize these errors. Spreader calibrations can be performed by using collection trays to determine the (field) spread pattern, but this is very time-consuming and expensive for the farmer and hence not common practice. Therefore, we developed an innovative multi-camera system to predict the spread pattern in a fast and accurate way, independent of the spreader configuration. Using high-speed stereovision, ejection parameters of particles leaving the spreader vanes were determined relative to a coordinate system associated with the spreader. The landing positions and subsequent spread patterns were determined using a ballistic model incorporating the effect of tractor motion and wind. Experiments were conducted with a commercial spreader and showed a high repeatability. The results were transformed to one spatial dimension to enable comparison with transverse spread patterns determined in the field and showed similar results
Measuring teat dimensions using image analysis
The interaction between teat and teatcup liner can strongly affect the milking characteristics and udder health. Therefore teat morphology is an important parameter in choosing the most appropriate liner. Nevertheless, teat morphology is rarely considered in choosing a teatcup liner. Gathering information on teat morphology on large scale with current techniques is time consuming, subjective and not always accurate. However, the ability to measure teat shape parameters in an easy way and on large scale has many applications. This study presents a new vision based measuring system that uses a camera to obtain a 2D image of the teat and image processing analyses to determine teat length and diameters. The technique is proven to be accurate (error less than 6%), repeatable and reproducible for both teat length and diameters
The Use of High-Speed Imaging Systems for Applications in Precision Agriculture
UB Dijon EcolDurInternational audienceThe book "New Technologies - Trends, Innovations and Research" presents contributions made by researchers from the entire world and from some modern fields of technology, serving as a valuable tool for scientists, researchers, graduate students and professionals. Some practical applications in particular areas are presented, offering the capability to solve problems resulted from economic needs and to perform specific functions. The book will make possible for scientists and engineers to get familiar with the ideas from researchers from some modern fields of activity. It will provide interesting examples of practical applications of knowledge, assist in the designing process, as well as bring changes to their research areas. A collection of techniques, that combine scientific resources, is provided to make necessary products with the desired quality criteria. Strong mathematical and scientific concepts were used in the applications. They meet the requirements of utility, usability and safety. Technological applications presented in the book have appropriate functions and they may be exploited with competitive advantages. The book has 17 chapters, covering the following subjects: manufacturing technologies, nanotechnologies, robotics, telecommunications, physics, dental medical technologies, smart homes, speech technologies, agriculture technologies and management
2D vision based measuring device for teat morphology in dairy cows
Teat morphology is an important parameter in choosing the most appropriate teatcup liner for a herd since the interaction between teat and liner can strongly affect the milking characteristics and udder health. Nevertheless, information on teat morphology is very scarce and rarely sufficient for liner selection. Gathering information on large scale with current techniques is time consuming, subjective and not always accurate. However, the ability to measure teat parameters in an easy way and on large scale has many applications. This study presents a new vision based measuring technique for teat shape parameters. A camera is used to obtain a 2D image of the teat and image processing analyses to determine teat length and diameters. In addition, shape parameters of teat and teat end can be defined. The resolution in length and diameters is better than 0.5 mm. The error on the length of the teats that make an angle in the longitudinal plane of maximum 25° towards the camera, is no more than 5 %. To validate the repeatability of the measuring method, the teats of one Holstein cow were measured 5 times by 8 different members of a test panel of which 5 people were experienced in working with cows. Reproducibility was tested by measuring the teats of 7 Holstein cows by the same test panel. The teats of each cow were measured once in a defined order. The sequence in which the members measured the teats was randomized. No significant differences were found between the 5 successive measurements of one person on 3 teats. Significant differences in left-front teat measurements (p=0.002) were due to the lack of cow experience (p=0.022). Teat length measurements did not significantly differ between members of the test panel as long as teats could be easily reached. However, no significant differences were found for all teats between operators familiar with cows. In conclusion, a new accurate, repeatable and reproducible method was developed to measure teat parameters in all kinds of milking parlours. To obtain repeatable and reproducible results, some training in working in close interaction with cows is advised
A 3-D stereovision system for fertilizer granule characterization
Machine vision evolved considerably in the last decade. The positive price evolution and robustness of the cameras combined with the high accuracy have led to their widespread use in different agricultural sectors. Our consortium presented different image based methods to measure the speed and direction of fertiliser grains. Currently, a first attempt to extract 3D-information with an image acquisition system based on stereoscopy is presented. The system uses previously developed and tested 2-D techniques. Depending on the imposed vertical angle, the first stereovision system showed an average error between 0,1% and 2,2% for measuring distance and height difference between grains. The second set-up showed promising results when comparing the measured values to the imposed velocity. Preliminary tests indicated that the designed stereovision system is capable of performing high speed 3D measurements on grains. More tests and research are necessary to further develop this first approach to a useful tool for spreading
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