3-D Modeling of Tomato Canopies Using a High-Resolution Portable Scanning Lidar for Extracting Structural Information

In the present study, an attempt was made to produce a precise 3D image of a tomato canopy using a portable high-resolution scanning lidar. The tomato canopy was scanned by the lidar from three positions surrounding it. Through the scanning, the point cloud data of the canopy were obtained and they were co-registered. Then, points corresponding to leaves were extracted and converted into polygon images. From the polygon images, leaf areas were accurately estimated with a mean absolute percent error of 4.6%. Vertical profile of leaf area density (LAD) and leaf area index (LAI) could be also estimated by summing up each leaf area derived from the polygon images. Leaf inclination angle could be also estimated from the 3-D polygon image. It was shown that leaf inclination angles had different values at each part of a leaf

A comparison of low-cost techniques for three-dimensional animal body measurement in livestock buildings

Data about health and development of animals are still now mostly collected through manual measurements or visual observations but these kinds of methods of collecting data are causes of several problems. Alternatively, optical sensing techniques can be implemented in order to overcome limitations arising from manual contact measurements. The present research discusses metrological analysis of Structure from motion (SfM) photogrammetry approach, low-cost LiDAR scanning and Microsoft Kinect v1 depth camera to three- dimensional animal body measurement, with specific reference to pigs. Analyses were carried out on fiberglass model to get rid of animal movements. Scans were captured based on a segmented approach, where different portion of the body have been imaged during different frames acquisition tasks. The obtained results demonstrate the high potential of 3D Kinect. LiDAR show a higher RMS value respect to Kinect and SfM most probably due to the collection approach based on single profiles rather than on surfaces. Anyway, the RMS of relative noise ranges between 0.7 and 4 mm, showing a high accuracy of reconstructions even for the others techniques

Comparison of forest attributes derived from two terrestrial lidar systems.

Abstract Terrestrial lidar (TLS) is an emerging technology for deriving forest attributes, including conventional inventory and canopy characterizations. However, little is known about the influence of scanner specifications on derived forest parameters. We compared two TLS systems at two sites in British Columbia. Common scanning benchmarks and identical algorithms were used to obtain estimates of tree diameter, position, and canopy characteristics. Visualization of range images and point clouds showed clear differences, even though both scanners were relatively high-resolution instruments. These translated into quantifiable differences in impulse penetration, characterization of stems and crowns far from the scan location, and gap fraction. Differences between scanners in estimates of effective plant area index were greater than differences between sites. Both scanners provided a detailed digital model of forest structure, and gross structural characterizations (including crown dimensions and position) were relatively robust; but comparison of canopy density metrics may require consideration of scanner attributes

3차원 스캔 모델과 광학 시뮬레이션을 이용한 파프리카의 생육 단계 및 차광 조건별 수광과 광합성 속도 예측

학위논문 (석사)-- 서울대학교 대학원 : 농업생명과학대학 식물생산과학부(원예과학전공), 2019. 2. 손정익.In greenhouses, many crops are cultivated at high planting densities because this type of cultivation is highly productive and presents economic advantages. A high planting density causes strong mutual shading effects among adjacent crops, decreasing canopy light interception, photosynthesis, and consequently, crop yield and quality. The objective of this study was to analyze the light interception and photosynthetic rates of the paprika canopy using 3D-scanned plant models and optical simulation according to the growth stage and shading condition. Here, 3D plant models of paprika plants grown in greenhouses were constructed at 7, 35, 63, 91, and 112 days after transplanting by using a portable 3D scanner. To investigate the shading effects, the 3D-scanned plant models were arranged as isotropic forms of 1 × 1, 3 × 3, 5 × 5, 7 × 7, and 9 × 9 plants with a distance of 60 cm between plants, and the light interception of the center plant in the arrangement was obtained with the growth stage by simulation. The canopy photosynthetic rates were calculated using the Farquhar, von Caemmerer, and Berry (FvCB) model. The total canopy light interception and light interception per unit leaf area of the center plant decreased due to the self- and mutual shading effects caused by the growth of each plant and the increase in the number of surrounding plants. The canopy photosynthetic rates showed similar patterns to those of the total light interception, but their decreasing rate was less than that of the total light interception because the leaf photosynthetic rate was saturated at the top of the canopy. In this study, the spatial distributions of the canopy light interception and photosynthetic rates could be analyzed by using 3D-scanned models of paprika and optical simulation. This method can be an effective tool for designing crop cultivation systems as well as estimating canopy light interception and photosynthesis in greenhouses.온실에서는 높은 단위 생산성을 위해 높은 재식 밀도로 작물을 재배한다. 그러나 높은 재식 밀도 조건에서는 인접한 개체에 의한 상호 차광이 발생하여 캐노피 수광과 광합성을 감소시키고, 결과적으로 작물 수량과 품질의 저하를 초래한다. 이에 따라 최적 재식 밀도를 찾기 위한 연구가 진행되었으나, 이를 간접적인 단위로 표현하여 작물 간의 상호 작용에 대한 분석이 어렵다. 따라서 본 연구의 목적은 3차원 스캔 모델과 광학 시뮬레이션을 이용하여 파프리카의 생육 단계와 차광 조건에 따른 수광과 광합성 속도를 분석하는 것이다. 3차원 스캐닝을 통해 정식 후 7, 35, 63, 91, 112일의 작물 모델을 구축하였다. 작물의 차광 효과를 분석하기 위해 작물 모델을 60cm 간격으로 1 × 1, 3 × 3, 5 × 5, 7 × 7, 9 × 9로 정방형 배치하여 생육 단계별 시뮬레이션을 진행하였고, 중심에 위치한 개체의 수광량을 계산하였다. 캐노피 광합성 속도는 FvCB 모델을 이용하여 계산하였다. 시뮬레이션 결과 모든 생육 단계에서 주변 개체 수가 증가할수록 작물 수광량은 감소하였다. 특히, 단위 엽면적당 수광량은 작물의 생육이 진행됨에 따라 감소하였다. 이는 각 작물의 생육에 따른 자기 광 차단과 주변 작물의 증가에 따른 상호 광 차단 효과 때문으로 생각된다. 이산화탄소 소모량은 총 수광량과 비슷한 변화 양상을 보였으나, 작물 상단부에서 광합성 포화가 나타났기 때문에 수광량 변화에 감소율은 작았다. 본 실험에서는 파프리카의 3차원 스캔 모델과 광학 시뮬레이션을 이용하여 생육 단계와 주변 개체의 증감에 따른 작물의 수광과 광합성 변화를 분석할 수 있었다. 이는 추후 온실 내에서 작물 재배 시스템을 디자인하고, 수광과 광합성을 예측하는 데에 효과적인 방법이 될 수 있을 것이다.ABSTRACT i CONTENTS iii LIST OF TABLES iv LIST OF FIGURES v INTRODUCTION 1 LITERATURE REVIEW 3 MATERIALS AND METHODS 6 DISCUSSION 12 CONCLUSION 24 LITERATURE CITED 29 APPENDICES 37 ABSTRACT IN KOREAN 40Maste

Pre-Processing of Point-Data from Contact and Optical 3D Digitization Sensors

Contemporary 3D digitization systems employed by reverse engineering (RE) feature ever-growing scanning speeds with the ability to generate large quantity of points in a unit of time. Although advantageous for the quality and efficiency of RE modelling, the huge number of point datas can turn into a serious practical problem, later on, when the CAD model is generated. In addition, 3D digitization processes are very often plagued by measuring errors, which can be attributed to the very nature of measuring systems, various characteristics of the digitized objects and subjective errors by the operator, which also contribute to problems in the CAD model generation process. This paper presents an integral system for the pre-processing of point data, i.e., filtering, smoothing and reduction, based on a cross-sectional RE approach. In the course of the proposed system development, major emphasis was placed on the module for point data reduction, which was designed according to a novel approach with integrated deviation analysis and fuzzy logic reasoning. The developed system was verified through its application on three case studies, on point data from objects of versatile geometries obtained by contact and laser 3D digitization systems. The obtained results demonstrate the effectiveness of the system

Innovative LIDAR 3D Dynamic Measurement System to Estimate Fruit-Tree Leaf Area

In this work, a LIDAR-based 3D Dynamic Measurement System is presented and evaluated for the geometric characterization of tree crops. Using this measurement system, trees were scanned from two opposing sides to obtain two three-dimensional point clouds. After registration of the point clouds, a simple and easily obtainable parameter is the number of impacts received by the scanned vegetation. The work in this study is based on the hypothesis of the existence of a linear relationship between the number of impacts of the LIDAR sensor laser beam on the vegetation and the tree leaf area. Tests performed under laboratory conditions using an ornamental tree and, subsequently, in a pear tree orchard demonstrate the correct operation of the measurement system presented in this paper. The results from both the laboratory and field tests confirm the initial hypothesis and the 3D Dynamic Measurement System is validated in field operation. This opens the door to new lines of research centred on the geometric characterization of tree crops in the field of agriculture and, more specifically, in precision fruit growing

3D Maize Plant Reconstruction Based on Georeferenced Overlapping LiDAR Point Clouds

3D crop reconstruction with a high temporal resolution and by the use of non-destructive measuring technologies can support the automation of plant phenotyping processes. Thereby, the availability of such 3D data can give valuable information about the plant development and the interaction of the plant genotype with the environment. This article presents a new methodology for georeferenced 3D reconstruction of maize plant structure. For this purpose a total station, an IMU, and several 2D LiDARs with different orientations were mounted on an autonomous vehicle. By the multistep methodology presented, based on the application of the ICP algorithm for point cloud fusion, it was possible to perform the georeferenced point clouds overlapping. The overlapping point cloud algorithm showed that the aerial points (corresponding mainly to plant parts) were reduced to 1.5%–9% of the total registered data. The remaining were redundant or ground points. Through the inclusion of different LiDAR point of views of the scene, a more realistic representation of the surrounding is obtained by the incorporation of new useful information but also of noise. The use of georeferenced 3D maize plant reconstruction at different growth stages, combined with the total station accuracy could be highly useful when performing precision agriculture at the crop plant level

Desarrollo de un robot cnc tipo cartesiano de la marca farmbot como soporte tecnológico para el proceso de control de calidad de plantines.

El trabajo de investigación presenta la implementación de un robot CNC del tipo cartesiano de la marca Farmbot como soporte tecnológico para el desarrollo de algoritmos en procesamiento de imágenes para el proceso de control de calidad en viveros industriales. Partiendo de la estructura metálica, los componentes que comprende el sistema electrónico como firmware, herramientas y la visión artificial, finalmente el desarrollo de algoritmos para el procesamiento de imágenes a través de internet.This research presents the efficient implementation of a CNC Farmbot Cartesian robot for the development of algorithms in image processing and the design of programs via Internet for robot applications in orchards and industrial nurseries. First, the mechanical-electrical structure of the robot is implemented. Second, electronic components, firmware, robots work tools and the artificial vision are installed. Finally, the development of algorithms for the processing of images through the internet.Tesi