Evaluation of low-cost depth cameras for agricultural applications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology- related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at different positions within the image, and cameras usefulness in indoor and outdoor settings. Then, cameras were tested in a swine facility and in a corn field. Five different cameras were used: (1) Microsoft Kinect v.1, (2) Microsoft Kinect v.2, (3) Intel® RealSenseTM Depth Camera D435, (4) ZED Stereo Camera (StereoLabs), and (5) CamBoard Pico Flexx (PMD Technologies). Results indicate that there were significant camera to camera differences for ZED Stereo Camera and Kinect v.1 camera (p \u3c 0.05). All cameras showed an increase in the standard deviation as the distance between camera and object increased; however, the Intel RealSense camera had a larger increase. Time-of-flight cameras had the smallest error between different sizes of objects. Time-of-flight cameras had non-readable zones on the corners of the images. The results indicate that the ToF technology is the best to be used for indoor applications and stereoscopy is the best technology for outdoor applications

Evaluation of low-cost depth cameras for agricultural applications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at different positions within the image, and cameras usefulness in indoor and outdoor settings. Then, cameras were tested in a swine facility and in a corn field. Five different cameras were used: (1) Microsoft Kinect v.1, (2) Microsoft Kinect v.2, (3) Intel® RealSense™ Depth Camera D435, (4) ZED Stereo Camera (StereoLabs), and (5) CamBoard Pico Flexx (PMD Technologies). Results indicate that there were significant camera to camera differences for ZED Stereo Camera and Kinect v.1 camera (p \u3c 0.05). All cameras showed an increase in the standard deviation as the distance between camera and object increased; however, the Intel RealSense camera had a larger increase. Time-of-flight cameras had the smallest error between different sizes of objects. Time-of-flight cameras had non-readable zones on the corners of the images. The results indicate that the ToF technolog

Sistema automatizado para aquisição de dados de umidade relativa do ar

Devido à importância do ambiente na produção animal e vegetal e, portanto, controle ambiental adequado, o trabalho propõe como objetivo a construção de um sistema de aquisição automatizada de dados de umidade relativa do ar, utilizando-se de microcontrolador de dimensões reduzidas e de baixo custo. A calibração do sensor de umidade relativa foi realizada em três etapas de simulação desenvolvidas em laboratório: caixas perfuradas, dessecador sem tampa contendo sílica-gel em seu fundo e psicrometria. As etapas de calibração, utilizando situações naturais e artificiais, bem como as metodologias desenvolvidas, apresentaram resultados que permitem concluir que o sistema pode ser utilizado com segurança no monitoramento dessa variável

Evaluation of low-cost depth cameras for agricultural applications

Low-cost depth-cameras have been used in many agricultural applications with reported advantages of low cost, reliability and speed of measurement. However, some problems were also reported and seem to be technology related, so understanding the limitations of each type of depth camera technology could provide a basis for technology selection and the development of research involving its use. The cameras use one or a combination of two of the three available technologies: structured light, time-of-flight (ToF), and stereoscopy. The objectives were to evaluate these different technologies for depth sensing, including measuring accuracy and repeatability of distance data and measurements at different positions within the image, and cameras usefulness in indoor and outdoor settings. Then, cameras were tested in a swine facility and in a corn field. Five different cameras were used: (1) Microsoft Kinect v.1, (2) Microsoft Kinect v.2, (3) Intel® RealSense™ Depth Camera D435, (4) ZED Stereo Camera (StereoLabs), and (5) CamBoard Pico Flexx (PMD Technologies). Results indicate that there were significant camera to camera differences for ZED Stereo Camera and Kinect v.1 camera (p \u3c 0.05). All cameras showed an increase in the standard deviation as the distance between camera and object increased; however, the Intel RealSense camera had a larger increase. Time-of-flight cameras had the smallest error between different sizes of objects. Time-of-flight cameras had non-readable zones on the corners of the images. The results indicate that the ToF technolog

Análise de métodos de estimativa de evapotranspiração na otimização de sistemas de drenagem

Inúmeros são os métodos para se estimar a evapotranspiração potencial (ETP) em que os mais simplificados apresentam limitações quanto à precisão dos resultados obtidos e os mais complexos apontam a dificuldade de se dispor de todos os dados necessários ao cálculo. No presente trabalho, compararam-se os métodos de Thornthwaite e Camargo com o de Penman-Monteith, tomado como padrão, com o objetivo de se verificar qual a influência da utilização de cada método na estimativa da ETP diária sobre o dimensionamento econômico de um sistema de drenagem, utilizando-se o modelo SISDRENA. Pelos resultados obtidos concluiu-se que as diferenças entre os métodos não afetaram significativamente a obtenção do espaçamento econômico entre drenos