Vineyards represent one of the main crop systems of greatest importance in the world economy, both in terms of the value chain of wine production and in its current expression of generating tradable goods. One of the ...
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Vineyards represent one of the main crop systems of greatest importance in the world economy, both in terms of the value chain of wine production and in its current expression of generating tradable goods. One of the challenges of grape production is grapevine health, which annually forces the winegrowers to incur fixed costs associated with the prevention and/or treatment of pests and diseases, causing an impact on the environment due to the application of phytosanitary products. Among the various diseases affecting grapevines, downy mildew ( Plasmopara viticola ) stands out, which causes negative impacts throughout the phenological cycle, particularly on leaves by affecting the absorption of photosynthetic pigments and consequent chlorophyll production, ultimately influencing grape yield and quality. Traditional methods for detecting vineyard diseases are often insufficient in crop protection, favoring new forms of a more agile decision support with timely responses. Proximal sensing trough optical sensors can assist in early disease detection. In this context, thermal infrared sensors stand out for their ability to capture changes in thermal response of leaves due to changes in grapevine metabolism and photosynthetic production. This study aims to explore the use of thermal infrared imagery to assess the detection of downy mildew by evaluating temperature variations in the surface of grapevine leaves when compared with non-infected leaves in a vineyard plot of the cv. Loureiro. The effects of temporal and spatial variability on the temperature of mildew-infected vine leaves are reported. A temperature variation of 2.71 °C was found within the same leaf when comparing to infected and non-infect areas. As the infection progresses over time, thermal variation tends to increase.
In this paper we compare the performance of a dead-reckoning system for robot navigation to a system using an Extended Kalman Filter (EKF). Dead-reckoning systems are able to approximate position and orientation by fe...
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ISBN:
(纸本)0819426415
In this paper we compare the performance of a dead-reckoning system for robot navigation to a system using an Extended Kalman Filter (EKF). Dead-reckoning systems are able to approximate position and orientation by feeding data (provided usually by local sensors) to the kinematic model of the vehicle. These systems are subject to many different sources of error. EKFs have the ability to combine the same information and compensate for most of these errors to yield a better estimate. Our simulation results using a simplified kinematic model of Rocky 7 (an experimental rover used in the Mars exploration program at Jet Propulsion Laboratory (JPL)) show that an improvement in performance up to 40% (position error) can be achieved. The local sensors used are: wheel encoders, steering angle potentiometer and gyroscope. Involvement of global sensor measurements can drastically increase the accuracy of the estimate. The lack of GPS or magnetic field on Mars narrows our choices for global localization. Landmarks, such as the sun can be used as natural beacons (reference point for absolute measurements). A sun sensor (SS) that measures the absolute orientation of the rover has been built by Lockheed Martin and now is part of the sensor suite of Rocky 7. The SS measurement is crucial for the estimation filter and we show that the accuracy of the estimation decreases exponentially as the frequency of the SS data fed to the EKF decreases.
The advent of multiple degree of freedom, dextrous robot hands has made robot hand control more complicated. Besides the existing problem of finding a suitable grasping position and approach orientation, it is now nec...
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Our objective is to recognize parts in a structured environment (such as a factory) using inexpensive and widely available hardware. In this paper we consider the class of parts with constant polygonal cross section. ...
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This paper introduces a method to detect and identify faults in wheeled mobile robots. The idea behind the method is to use adaptive estimation to predict (in parallel) the outcome of several faults. Models of the sys...
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The aim of this paper is to evaluate the Transmission control protocol (TCP) delay performance of IeeE802.11 WLANs using Wireshark which is a network performance monitoring tool. It also shows a detailed study of snif...
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Several studies suggest that robots can play a relevant role to address Autistic Spectrum Disorder (ASD). This paper presents a humanoid social robot-assisted behavioral system based on a therapeutic multilevel treatm...
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ISBN:
(纸本)9781450345606
Several studies suggest that robots can play a relevant role to address Autistic Spectrum Disorder (ASD). This paper presents a humanoid social robot-assisted behavioral system based on a therapeutic multilevel treatment protocol customized to improve eye contact, joint attention, symbolic play, and basic emotion recognition. In the system, the robot acts as a social mediator, trying to elicit specific behaviors in child, taking into account his/her multimodal signals. Statistical differences in eye contact and facial expression imitation behaviors after the use of the system are reported as preliminary results.
Current work presents a vibration suppression strategies of a Non-Deformable Metal Strip which is induced by rapid action of an industrial robot. In this case an external controller is designed as outer controller wit...
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Process planning for machined parts typically requires that a part be described through machining features such as holes, slots and pockets. This paper presents a novel feature finder, which automatically generates a ...
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