4,528 research outputs found

    The Design and Development of an Automatic Guiding System for a Tractor

    Get PDF
    Mechanization and Automation are very fashionable words in present day Agriculture. Both imply a reduction in the amount of human effort necessary to achieve certain ends, and to accept the need for either of them is to assume that it will lead to some financial gain. Automation as applied to Agriculture is to improve many limited factors which affect the final yield of any agricultural crop. One of these factors, the mechanical operation, requires considerable care and attention to more nearly insure maximum yield and high quality. Numerous methods have been adopted through research and development to minimize field losses of a crop and to improve the quality of product with the use of more adaptable and accurate machines. As such, the objective of this study was: 1. To design, develop, and construct an automatic steering device which would enable a tractor to guide itself down the crop row accurately. The system was to be designed in a manner that would make it possible for the tractor to be used for a variety of crops with little or no change in the automatic steering components. 2. To design a system which could be justified economically where labor is scarce and expensive or unskilled, or where the tractors are operated in hazardous conditions

    GPS guidance system for automatic driving

    Get PDF
    Desde hace un tiempo, la automatización se ha convertido en una de las estrategias más importantes a implementar en la industria y en el día a día de las personas debido a sus beneficios, como una mayor seguridad o mayores tasas de producción. Por todo ello, la UCLL trabaja desde hace casi cuatro años en el proyecto Gepland Fruit que consiste en un vehículo autónomo que facilita la tarea de recogida de cajas en los campos de fruta. El objetivo principal de este proyecto es conseguir una conducción autónoma mediante conexión GPS. Se ha utilizado un programa de código abierto llamado AgOpenGPS que proporciona conexión GPS y cálculos de ángulo de dirección. En este proyecto, el código fuente ha sido modificado para que se conecte al sistema de control PLC que acciona el vehículo AGV autónomo. El propósito global sería lograr la conducción automática a través de un campo de frutas mientras recogiendo cajas que estaban al lado del camino.For some time now, automation has become one of the most important strategies to implement in the industry and in people's daily lives due to its benefits such as an improved safety or higher production rates. For all this, the UCLL has been working for almost four years in the Gepland Fruit project that consists of an autonomous vehicle that facilitates the task of box collection on fruit fields.The main goal of this project is to achieve autonomous driving using GPS connection. An opensource program called AgOpenGPS has been used thanks to its features, providing GPS connection and steering angle calculations. In this project, the source code has been modified so that it connects to the PLC control system that drives the autonomous vehicle. The final goal would be to achieve automatic driving across a fruit field while picking up boxes that lay next to the path.Departamento de Ingeniería de Sistemas y AutomáticaGrado en Ingeniería en Tecnologías Industriale

    Open and Closed Loop System Characteristics of a Tractor and an Implement Dynamic Model

    Get PDF
    Accurate guidance of towed implements is important for performing agricultural field operations and for gaining the ultimate benefit from an agricultural automatic guidance system. The study of open and closed loop system responses can be helpful in the design of practical guidance controllers. A dynamic model of a tractor and a towed implement system was developed. Open loop analysis of the kinematic and dynamic models revealed that the dynamic model was essential for capturing the higher order dynamics of the tractor and implement system at higher operating velocities. In addition, a higher fidelity dynamic model was also developed by incorporating steering dynamics and tire relaxation length dynamics. Closed loop system characteristics were studied by using a linear quadratic regulator (LQR) controller. The tractor position and heading and implement heading states along with respective rate states were fed back to close the loop. The higher fidelity closed loop system used a practical range of steering angles and rates to keep the response within nominal off-road vehicle guidance controller design specifications in the forward velocity range of 0.5 m/s to 10 m/s (1.8 km/h to 36 km/h). These simulation studies provided understanding about the characteristics of the tractor and towed implement system and showed promise in assisting in the development of automatic guidance controllers

    Volume 1 – Symposium: Tuesday, March 8

    Get PDF
    Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Components:Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Component

    HortiBot: A System Design of a Robotic Tool Carrier for High-tech Plant Nursing

    Get PDF
    Danish organic outdoor gardeners today use 50-300 hours per hectare for manual weeding. Through automatic controlling of an existing commercial machine this often heavy and costconsuming weeding will be eliminated. At the same time, a fully-automatic registration of field activities will contribute to the efficient implementation of EU directive 178/2002 concerning traceability in the primary production and thereby enhance the food-safety in the production chain. A radio controlled slope mower is equipped with a new robotic accessory kit. This transforms it into a tool carrier (HortiBot) for high-tech plant nursing for e.g. organic grown vegetables. The HortiBot is capable of passing over several parcels with visible rows autonomously based on a new commercial row detection system from Eco-Dan a/s, Denmark. This paper presents the solutions chosen for the HortiBot with regard to hardware, mechanicalelectrical interfaces and software. Further, the principles from a Quality Function Deployment (QFD) analysis was used to carry out the solicitation, evaluation and selection of most qualified design parameters and specifications attained to a horticultural robotic tool carrier. The QFD analysis provided a specific measure to evaluate each selected parameter in terms of satisfying user requirements and operational performance aspects. Based on a combination of importance rating and competitive priority ratings important user requirements include easy adaptation to field conditions in terms of row distance and parcel size, profitability, minimum crop damage during operation, and reliability. Lesser importance was attributed to affection value, attractive look, the possibility of out of season usage, and the use of renewable energy

    Soil sampling automation using mobile robotic platform

    Get PDF
    ArticleLand based drone technology has considerable potential for usage in different areas of agriculture. Here a novel robotic soil sampling device is being introduced. Unmanned mobile technology implementation for soil sampling automation is significantly increasing the efficiency of the process. This automated and remotely controlled technology is enabling more frequent sample collection than traditional human operated manual methods. In this publication universal mobile robotic platform is adapted and modified to collect and store soil s amples from fields and measure soil parameters simultaneously. The platform navigates and operates autonomously with dedicated software and remote server connection. Mechanical design of the soil sampling device and control software is introduced and discu ssed

    Development of an inexpensive guidance system for agricultural purposes

    Get PDF
    Robotics is a rapidly growing technology and robots have pervaded into most of the industries. Robotics and automation are designed to remove the human factor from the labor intensive and monotonous work and thereby decrease the associated costs. The application of robotics to agriculture is fairly recent. Robotic applications in agriculture vary from autonomous row-guidance tractors to fruit picking robots. Similarly, soil testing and soil sampling is one area in agriculture where automation of tasks and the employment of an autonomous robot would be of great use to consultants and farmers employing site specific farming techniques. Soil testing is an important part of farming used to determine the average nutrient status in a field and to obtain a measure of nutrient availability in the field. Fertilizers and other nutrients are applied to the fields based on different soil tests. Site specific farming is greatly dependent on soil testing and can result in increased yield, reduced cost and reduced water pollution. Soil testing requires a lot of soil samples and soil sampling is a time consuming, laborious process and expensive process. Most of the consultants employing site specific techniques use ATVs to get around large fields when sampling. The development of an autonomous guidance system for an ATV to perform soil sampling would be greatly beneficial to them. Labor costs would be significantly reduced and the operators would be subjected to fewer environmental elements. The use of ATVs ensures that no extra capital is needed to buy a vehicle. The use of a small vehicle like an ATV also causes less soil compaction. A WAAS enabled Differential GPS with accuracies to within 9.84 feet was used as the position sensor. Pocket PCs are more portable than a laptop computer and are more suitable for farm conditions. Shape files were used to provide the sampling points as input to the guidance program. A guidance program was made to operate on a PDA and provide guidance instructions. A microprocessor was programmed to read the guidance instructions and actuate the different components like throttle and steering. Tests were conducted to test the accuracy and consistency of the system. The offsets of each stop point from the test point were documented and analyzed. The results indicated that the system was as accurate as the GPS used for guidance. They also indicated that a guidance system can be realized with the use of very few components and an accuracy needed for soil sampling can be achieved. Avoidance routines for obstacles within the field were indicated as future developments

    전자유압밸브를 이용한 자율 주행 트랙터 조향성능 향상 연구

    Get PDF
    학위논문 (석사)-- 서울대학교 대학원 농업생명과학대학 바이오시스템·소재학부, 2017. 8. 김학진.The most common solution to achieving automated steering in an agricultural tractor is the use of an electric motor in parallel with a conventional hydrostatic valve-based hydraulic steering system owing to its simplicity and low cost. However, the existing overlap, or dead band, of a hydrostatic valve has limited its potential benefit to automated tractor steering in terms of providing various agricultural operations, including planting and spraying, at higher speeds. The main objective of this study was to develop an electro hydraulic steering system applicable to an auto-guidance system, and to compare the performance of the developed system with a conventional automatic steering system. A proportional-feedforward control algorithm was implemented to effectively compensate the non-linear behaviors of the hydraulic cylinders used for changing the steered wheel angle of the tractor. A computer-controlled hardware-in-the-loop electro-hydraulic steering simulator consisting of two different types of valve sub-systems s, i.e., hydrostatic valve and EHPV sub-system, was designed and built for the development of the steering control algorithms and to verify the feasibility of the developed steering controller for accurate steering of the system with acceptable response times. A field test was conducted using a Real Time Kinematic GPS based autonomous tractor equipped with the developed EHPV-based steering system and an EPS-based steering system used as a control to compare and investigate their potential in enhancing the path tracking functionality of an auto-guided system. The use of the EHPV-based steering controller was shown to improve the tracking error by about 29% and 50% for straight and curved paths, respectively, as compared to the EPS-based steering system.Chapter 1. Introduction 1 1.1. Study Background 1 1.2. Description of Tractor Steering System 6 1.3. Automatic Steering System 10 1.3.1. Electric Power Steering System 10 1.3.2. Electro Hydraulic Steering System 12 1.4. Review of Literature 13 1.5. Research Purpose 16 Chapter 2. Materials and Methods 17 2.1. Preliminary Performance Test of Conventional Steering System 17 2.1.1. Purpose of Preliminary Test 17 2.1.2. Zero-Load Test 21 2.1.3. Tractor Traveling Test 22 2.2. Hardware-in-the Loop Simulator 24 2.2.1. Hydraulic Circuit 25 2.2.2. Hardware Description 27 2.3. ISO 11783 Network 37 2.3.1. ISO 11783 (ISOBUS) 37 2.4. Steering Control Algorithm 45 2.4.1. Dead Time 48 2.4.2. Dead Band 51 2.4.3. Static Friction 57 2.5. Virtual Terminal 61 2.6. Vehicle Traveling Test 66 2.6.1. Hardware Configurations 66 2.6.2. Trajectory Tracking Control 72 2.6.3. Zero-Load Test 74 2.6.4. Sinusoidal Tracking Test 75 2.6.5. Path-Tracking and Test Methods 76 2.6.6. Evaluation Method of Path Tracking Deviation 79 Chapter 3. Results and Discussion 81 3.1. Preliminary Test Results of EPS-based Hydrostatic Steering System 81 3.2. Experiment Results of Steering Behavior of Hydrostatic Steering System using HIL simulator 85 3.3. Experiment Results of Electrohydraulic Steering System using HIL simulator 81 3.3.1. Dead-Time Approximation 88 3.3.2. Dead-Band Compensation 90 3.3.3. Static Friction Compensation 92 3.3.4. Steering Controller Test under Load Conditions 94 3.4. Performance Evaluation of Tractor Steering System 96 3.4.1. Zero Load Test 96 3.4.2. Sinusoidal Steering Test 96 3.4.3. Path-Tracking Test 99 Chapter 4. Conclusions 107Maste

    Summary of NASA landing-gear research

    Get PDF
    Research relative to tire tread, powered-wheel taxiing, air cushion landing systems, and crosswind landing gear is discussed
    corecore