<p>Syftet med denna studie var att utreda hur röststyrning kan användas för kontroll av aggregatet på en engreppsskördare.</p><p> </p><p>För att studera röststyrning genomfördes en så kallad Wizard of Oz-studie. Metoden går ut på att en människa ersätter en funktion i ett system som ännu inte finns eller är färdigutvecklad. I studien var det röstigenkänningen och inmatningen av korrekt respons som utfördes av en människa, trollkarlen. Rollen som trollkarl utfördes av en före detta skördarförare som numera arbetar som forskare på Skogforsk.</p><p> </p><p>Studien genomfördes i Skogforsks skogsmaskinsimulator. I den kan en försöksperson på ett verklighetstroget sätt arbeta med en engreppsskördare. Som försökspersoner användes fem professionella förare.</p><p> </p><p>Innan en förare provade röststyrningen fick han köra simulatorn med konventionell styrning för att vänja sig vid hur maskinen kändes att köra i den simulerade miljön. Därefter fick föraren använda sig av röststyrning. Försökspersonerna som var omedvetna om trollkarlens existens fick endast instruktion om att slutavverka ett bestånd genom att kontrollera aggregatet med rösten. De fick inga förslag på kommandon eller uttryck att använda utan fick själva utforska systemet och använda det som de ville. Kranen kontrollerade de som vanligt med spakarna.</p><p> </p><p>Under studien observerades försökspersonernas agerande av försöksledaren och efteråt genomfördes en intervju om upplevelsen av röststyrningen.</p><p> </p><p>Alla förarna lärde sig snabbt att använda systemet och använde sig av samma princip. En knapptryckning ersattes med ett kommando. Förarna använde sig till en början av uttryck de var bekanta med sedan tidigare. De rationaliserade medvetet uttrycken de använde till att bli korta och nästan alltid bara innehålla ett ord.</p><p> </p><p>Överlag tyckte försökspersonerna att röststyrningen var en positiv upplevelse och tyckte att det fungerade bra men förutsåg att det skulle bli problematiskt att använda vid svårarbetad skog som kräver mycket manuell inblandning i apteringen.</p><p> </p><p>Röststyrningen verkar gynna användning av automatiska sekvenser.</p>

Syftet med denna studie var att utreda hur röststyrning kan användas för kontroll av aggregatet på en engreppsskördare.   För att studera röststyrning genomfördes en så kallad Wizard of Oz-studie. Metoden går ut på att en människa ersätter en funktion i ett system som ännu inte finns eller är färdigutvecklad. I studien var det röstigenkänningen och inmatningen av korrekt respons som utfördes av en människa, trollkarlen. Rollen som trollkarl utfördes av en före detta skördarförare som numera arbetar som forskare på Skogforsk.   Studien genomfördes i Skogforsks skogsmaskinsimulator. I den kan en försöksperson på ett verklighetstroget sätt arbeta med en engreppsskördare. Som försökspersoner användes fem professionella förare.   Innan en förare provade röststyrningen fick han köra simulatorn med konventionell styrning för att vänja sig vid hur maskinen kändes att köra i den simulerade miljön. Därefter fick föraren använda sig av röststyrning. Försökspersonerna som var omedvetna om trollkarlens existens fick endast instruktion om att slutavverka ett bestånd genom att kontrollera aggregatet med rösten. De fick inga förslag på kommandon eller uttryck att använda utan fick själva utforska systemet och använda det som de ville. Kranen kontrollerade de som vanligt med spakarna.   Under studien observerades försökspersonernas agerande av försöksledaren och efteråt genomfördes en intervju om upplevelsen av röststyrningen.   Alla förarna lärde sig snabbt att använda systemet och använde sig av samma princip. En knapptryckning ersattes med ett kommando. Förarna använde sig till en början av uttryck de var bekanta med sedan tidigare. De rationaliserade medvetet uttrycken de använde till att bli korta och nästan alltid bara innehålla ett ord.   Överlag tyckte försökspersonerna att röststyrningen var en positiv upplevelse och tyckte att det fungerade bra men förutsåg att det skulle bli problematiskt att använda vid svårarbetad skog som kräver mycket manuell inblandning i apteringen.   Röststyrningen verkar gynna användning av automatiska sekvenser.

Vibration energy harvesters, or energy scavengers, recover mechanical energy from their surrounding environment and convert it into useable electricity as sustainable self-sufficient power sources to drive micro-to milli-Watt scale power electronics in small, autonomous, wireless devices and sensors. Using semiconducting, organic piezoelectric nanomaterials are attractive in low-cost, high resistance to fatigue, and environmentally friendly applications. Significantly, the deposition processes of sputtering ZnO (zinc oxide) thin films with high c-axis preferred orientation and electrospun PVDF (polyvinylidene fluoride) nanofibers with high piezoelectric £]-phase crystallisation are controlled at room temperature. Thus they don¡¦t have the necessity of post-annealed and electrical repoling process to obtain an excellent piezoelectricity, and are suitable for all flexible substrates such as PET (polyethylene terephthalate) and PI (polyimide). These works are divided into two parts. Part 1: Flexible piezoelectric harvesters based on ZnO thin films for self-powering and broad bandwidth applications. A new design of Al (aluminum)/PET-based flexible energy harvester was proposed. It consists of flexible Al/PET conductive substrate, piezoelectric ZnO thin film, selectively deposited UV (ultraviolet)-curable resin lump structures and Cu (copper) foil electrode. The design and simulation of a piezoelectric cantilever plate was described by using commercial software ANSYS FEA (finite element analysis) to determine the optimum thickness of PET substrate, internal stress distribution, operation frequency and electric potential. With the optimum thickness predicted by developed accurate analytical formula analysis, the one-way mechanical strain that is efficient to enhance the induced electric potential can be controlled within the piezoelectric ZnO layer. In addition, the relationship among the model solution of piezoelectric cantilever plate equation, vibration induced electric potential and electric power was realized. ZnO thin film of high (002) c-axis preferred orientation with an excellent piezoelectricity was deposited on the Al/PET by RF (radio-frequency) magnetron sputtering in room temperature. Al was sputtered on the PET substrate as the bottom electrode because of its low sheet resistance, superior adhesion with PET, and lattice constants matching with ZnO thin film. The selectively deposited UV-curable resin lump structures as proof mass were directly constructed on flexible piezoelectric plate using electrospinning with a stereolithography technique. One individual harvester achieves a maximum OCV (open-circuit voltage) up to 4V with power density of 1.247 £gW/cm2. This self-powered storage system can drive the warning signal of the LED (light emitting diode) module in both resonant and non-resonant conditions. We also succeeded in accomplishing a broad bandwidth harvesting system with operating frequency range within 100 Hz to 400 Hz to enhance powering efficiency. This system comprises four units of individual ZnO piezoelectric harvester in the form of a cantilever structure connected in parallel, and rectifying circuit with storage module. In addition, a modified design of a flexible piezoelectric energy-harvesting system with a serial bimorph of ZnO piezoelectric thin film was presented to enhance significantly higher power generation. This high-output system was examined at 15 Hz. The maximum DC (direct current) voltage output voltage with loading was 3.18 V, and the maximum DC power remained at 2.89 £gW/cm2. Furthermore, in order to examine the deformation between interfaces and the adhesion mechanism of multi-layer flexible electronics composites (e.g., ITO (indium tin oxide)/PET, Al/PET, ZnO/ITO/PET, and ZnO/Al/PET), nanoscratching and nano-indention testing (nanoindenter XP system) were conducted to analyze the adhesion before and after the vibration test. The plastic deformation between the ductile Al film and PET substrate is observed using SEM (scanning electron microscopy). Delamination between the ZnO and Al/PET substrate was not observed. This indicates that Al film provides excellent adhesion between the ZnO thin film and PET substrate. Part 2: Pre-strained piezoelectric PVDF nanofiber array fabricated by near-field electrospining on cylindrical process for flexible energy conversion. In various methodologies of energy harvesting from ambient sources, one-dimensional nanoharvesters have been gaining more attention recently. However, these nanofibers fabricated by micro-forming technologies may not easily control their structural diameter and length. This study originally presented the HCNFES (hollow cylindrical near-field electrospining) process to fabricate permanent piezoelectricity of PVDF piezoelectric nanofibers. Under high in-situ electric poling and strong mechanical stretching effect during HCNFES process, large PVDF nanofiber array with high piezoelectric £]-phase crystallisation was demonstrated. These pre-strained piezoelectric PVDF nanofibers fabricated by HCNFES with high process flexibility at low cost, availability in ultra-long lengths, various thicknesses and shapes can be applied at power scavenge, sensing and actuation. Firstly, PVDF nanofibers lay on a PET substrate, silver paste was applied at both ends of fibers to fix their two ends tightly on a Cu foil electrode pair. The entire structure was packaged inside a thin flexible polymer to maintain its physical stability. Repeatedly stretching and releasing the nanoharvester (NH 1) with a strain of 0.05% at 5 Hz vibration created a maximum peak voltage and current of -50 mV and -10 nA in forward connection, respectively. Secondly, a total of 44 parallel nanofibers have been fabricated and transferred onto an IDT (interdigital) electrode with 64 electrode pairs as a nanohavester (NH 2) to amplify current outputs under repeated mechanical vibration and impact tests. Under a repeated maximum strain of 0.14% at 6 Hz vibration, a peak current of 39 nA and peak voltage of 20.2 mV have been measured. Impact testing at 15 Hz, peak current of 130 nA has been collected with a voltage of 24.4 mV. Finally, the single PVDF fiber as nanoharvester (NH 3) with a strain of 0.05-0.1% at 5 Hz vibration created a maximum peak voltage and current of -45 mV and -3.9 nA, respectively. The maximum power remained at 18.45 pW/cm2 with a load resistor of 6.8 M£[. Based on the mechanism of converes piezoelectric effect, ANSYS software with coupled field analysis was used to realize piezoelectric actuation behavior of the PVDF fibers. From the observation of actuation property, a fixed-fixed single nanofiber was tested under different DC voltage supply. Comparing the polarized fiber with non-polarized fibers, the measurement of the center displacements as a function of electric field was conducted and characterized.

Energy harvesting is becoming increasingly important in low-power applications where energy from the environment is used to power the system alone, or to supplement a battery. For example, pulse oximeter sensors inside helmets of road racing cyclists are powered by the sun. These sensors have become smaller and more practical without the limitation of a finite energy supply. Harvested energy from an energy transducer (solar, piezoelectric, etc.) must be maximized to ensure these devices can survive periods where environmental energy is scarce. The conversion process from the transducer to usable power for the device is not perfectly efficient. Specifically, the output voltage of a solar cell is a function of the light intensity, and by extension the load it powers. A small perturbation of the light source quickly diminishes the available power. The wasted power reduces the energy available for the application, and can be improved using an approach called maximum power point tracking (MPPT). This technique maximizes harvesting efficiency by dynamically impedance matching the transducer to its load. This report introduces the Maximum Efficient Solar Harvester (MESH), an MPPT algorithm tuned for a specific Wireless Sensor Network (WSN) application. MESH specifically controls the operation of the DC-DC converter in a solar power management unit (PMU). The control is done by monitoring the available light and feeding that information to choose the optimal operating point DC-DC converter. This operating point has a direct dependency on the overall efficiency of the system. For MESH to be practical, the cost and power overhead of adding this functionality must be assessed. Empirical results indicate that MESH improves the maximum efficiency of the popular Texas Instruments (TI) RF2500-SEH WSN platform by an average of 20%, which far exceeds the power overhead it incurs. The cost is also found to be minimal, as WSN platforms already include a large portion of the hardware required to implement MESH. The report was done in collaboration with Shahil Rais. It covers the hardware components and the bench automation environment; Rais's companion report focuses on software implementation and MESH architecture definition. / text

Yield monitors have become an indispensable part of precision agriculture systemsbecause of their ability to measure the yield variability. Accurate yield monitor data availabilityis essential for the assessment of farm practices. The current technology of measuring grainyields is prone to errors that can be attributed to mass flow variations caused by the mechanismswithin a grain combine. Because of throughput variations, there are doubts regarding thecorrelation between the mass flow measurement and the actual grain volume produced at aspecific location. Another inaccuracy observed in yield monitor data can be attributed to inexactcut-widths values entered by the machine operator.To effectively address these yield monitor errors, two crop mass flow sensing deviceswere developed and used to correct yield monitor data. The two quantities associated with cropmaterial mass flow that were sensed were tension on the feeder housing drive chain and thehydraulic pressure on the threshing cylinder's variable speed drive. Both sensing approacheswere capable of detecting zero mass flow conditions better than the traditional grain mass flowsensor. The alternative sensors also operate without being adversely affected by materialtransport delays. The feeder housing-based sensor was more sensitive to variations in cropmaterial throughput than the hydraulic pressure sensor. Crop mass flow is not a surrogate forgrain mass flow because of a weak relationship (R2 andlt; 0.60) between the two quantities. The cropmass flow signal does denote the location and magnitude of material throughput variations intothe combine. This delineation was used to redistribute grain mass flow by aligning grain andcrop mass flow transitions using sensor fusion techniques. Significant improvements (?? = 0.05)in yield distribution profile were found after the correction was applied.To address the cut-width entry error, a GIS-based post-processing algorithm wasdeveloped to calculate the true harvest area for each yield monitor data point. Based on theresults of this method, a combine operator can introduce yield calculation errors of 15%. Whenthese two correction methods applied to yield monitor data, the result is yield maps withdramatically improved yield estimates and enhanced spatial accuracy.

<p>The focus of this dissertation is on phenomena exhibited by multistable systems. Two phenomena of particular importance are chaos control and stochastic resonance. In this work, both models that can predict ordered responses and experiments in which ordered responses occur are explored. In addition, parameter identification methods are presented and improved. </p><p>Chaos control, when implemented with delays, can be an effective way to stabilize unstable periodic orbits within a multistable system experiencing a chaotic response. Delayed control is easy to implement physically but greatly increases the complexity of analyzing such systems. In this work, the spectral element method was adapted to evaluate unstable periodic orbits stabilized by feedback control implemented with delays. Examples are presented for Duffing systems in which the delay is equal to the forcing period. The spectral approach is also extended to analyze the control of chaos with arbitrary delays. Control with arbitrary delays can also be used to stabilize equilibria within the chaotic response. These methods for arbitrary delays are explored in self-excited, chaotic systems.</p><p>Stochastic resonance occurs in multistable systems when an increase in noise results in an ordered response. It is well known that noise excitation of multistable systems results in the system escaping from potential wells or switching between wells. In stochastic resonance, a small external signal is amplified due to these switching events. Methods for modeling stochastic resonance in both underdamped and overdamped systems are presented. In addition, stochastic resonance in a bistable, composite beam excited by colored noise is investigated experimentally. The experimental results are compared with analytical models, and the effect of modal masses on the analytical expressions is explored. Finally, an alternative approach for calculating the effect of colored noise excitation is proposed.</p><p>In order to implement analysis methods related to delay differential equations or stochastic resonance, the parameters of the system must be known in advance or determined experimentally. Parameter identification methods provide a natural connection between experiment and theory. In this work, the harmonic balance parameter identification method was applied to beam energy harvesters and is improved using weighting matrices. The method has been applied to a nonlinear, bistable, piezoelectric beam with a tip mass. Then, an experimental method of determining the number of restoring force coefficients necessary to accurately model the systems was demonstrated. The harmonic balance method was also applied to a bistable, beam system undergoing stochastic resonance. Finally, a new weighting strategy is presented based on the signal to noise ratio of each harmonic.</p> / Dissertation

A escolha do espaçamento de plantio tem como objetivo inicial proporcionar para cada árvore o espaço suficiente para se obter o crescimento máximo com melhor qualidade e menor custo. Do ponto de vista da colheita mecanizada, o aumento da densidade da floresta implica diretamente na redução do volume individual das árvores, ocasionando também uma redução da capacidade produtiva do harvester.O objetivo deste estudo foi avaliar o efeito de diferentes espaçamentos e arranjos do plantio de povoamentos de eucalipto sobre a capacidade e custo operacional da colheita com harvester. A coleta de dados de produtividade do harvester foi feita em condições reais de operação, em dois povoamentos de eucalipto com diferentes espaçamentos: 6,0; 7,5; 9,0; 12; e 18 m2 por árvore, além do uso de um simulador de colheita. Usando-se os valores das variáveis espaçamento (E), volume médio (VM), diâmetro à altura do peito (DAP) e altura (H) aplicou-se um teste de regressão stepwise e se fez uma correlação para medir a participação dessas variáveis na capacidade operacional. Os custos operacionais dos equipamentos foram determinados através de um método contábil proposto pela FAO. O volume médio (VM) por árvore explicou 88 % da capacidade operacional da colhedora florestal e o espaçamento (E) afetou 8,5 %, sendo que o maior espaçamento é a causa do maior volume individual. Conseqüentemente, o custo da operação de colheita de árvores com harvester foi menor naqueles tratamentos com maior espaçamento. Os tratamentos simulados podem ser utilizados como reais para este tipo de comparação, dado que os tratamentos usando o simulador seguem a mesma tendência que a colheita real, ou seja, a maior espaçamento, maior volume individual por árvore e por tanto maior capacidade operacional do harvester. A maior proporção de tempo médio do ciclo de colheita por árvore foi o tempo de traçamento em condições de trabalho real, sendo que no caso da simulação da colhedora o maior tempo do ciclo foi de descasque-desgalhe. O modelo empírico apresentado pode ser uma ferramenta válida para predição de capacidade operacional do harvester. / Plantation spacing selection has the primary object of assigning each tree enough space in which maximum growth and best quality can be attained with a minimum cost. From the harvest standpoint, an increase in stand density directly implies a decrease of individual tree volume, reducing also harvester productive capacity. The objective of this research is to assess the effects of several initial spacing and arrangement in eucalypt plantations on production capacity and operational capacity and costs of forest harvester. Real operational data were collected from two eucalypt plantations at different initial spacing, viz. 6.0, 7.5, 9.0, 12 and 18 m2 per tree. Simulation data were obtained from forest harvester simulator. Using spacement (E), mean tree volume (MV), diameter at breast height (DBH) and height (H) values, a stepwise regression test procedure was run, and correlations computed in order to measure their participation in operational capacity. Operational costs were computed with accounting method proposed by FAO. Mean tree volume (MV) explained 88% of forest harvester operational capacity. Spacement (E) affected 8.5% of harvester operational capacity; wider spacements were related to higher individual tree volumes. Harvesting operation costs were lower in wider spaced treatments. Simulated treatments can be used as in field conditions. Treatments under simulated conditions and real conditions had the same results: the wider the spacement, more individual volume tree and higher harvester operational capacity. The higher time of the harvest cycle was the cross-cutting operation in real conditions and the debarked and delimbing in simulated conditions. The empirical model can be a valid tool to predict the harvester operational capacity

Orientador: Kléber Pereira Lanças / Banca: Saulo Philipe Sebastião Guerra / Banca: Paulo Roberto Arbex Silva / Banca: Ila Maria Corrêa / Banca: Nilson Salvador / Resumo: As colhedoras atuais de cana-de-açúcar são autopropelidas, com todo acionamento, das peças ativas e locomotoras, hidráulico. O cortador de base é composto por dois discos contra rotativos, com cinco lâminas retangulares cada, que cortam os colmos em sua base por impacto. Um rolo defletor empurra os caules para frente antes do corte para auxiliar na alimentação da máquina. A deflexão e o corte de base por impacto são responsáveis por danos na soqueira e no produto colhido. Estes danos aceleram o processo de deterioração, aumentam o nível de perdas e prejudica a rebrota. O objetivo desta pesquisa foi desenvolver e avaliar um sistema de corte de base que não se baseie no corte por impacto e que possa ser adaptado em qualquer colhedora comercial sem a necessidade de alterações na máquina. Para alcançar o objetivo proposto, foi realizado um estudo cinemático de lâminas curvas e foram conduzidos experimentos de laboratório e campo. Os discos do cortador de base estão sujeitos a dois movimentos, rotação e translação (avanço da colhedora). O estudo cinemático descreve estes movimentos em forma de matrizes. Foram elaborados programas com o uso do software MATLAB para a realização de uma simulação virtual, usada para investigar as configurações alternativas do cortador de base e fornecer subsídios para um desenvolvimento teórico do processo de corte da cana-de-açúcar. No laboratório foi construída uma estrutura de teste que simulava os movimentos de rotação e translação do disco, para cortar uma amostra do caule da cana-de-açúcar. Foram realizados dois experimentos; no primeiro foi utilizado um delineamento estatístico em esquema fatorial onde foi avaliado o passo do serrilhado, o ângulo horizontal da lâmina com inclinação para frente e para trás e a velocidade de corte. Foram analisados os danos no caule, perdas de massa, forças e energia de corte... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The current sugar cane harvesters are self propelled and all transmissions are hydraulic. The basecutting mechanism consists of two rotating discs, with five rectangular blades each, which cut the stalk at its base by impact. A knockdown roller pushes the stem forward before the cut to assist the machine feeding. The deflection and the basecutting by impact are responsible for damage to the stump and harvested product. This damage accelerates the deterioration process, increases the level of losses, damage and reduces the ratoon. The objective of this research was to develop and evaluate a basecutter system that is not based on the impact cut and can be adapted to any commercial harvester without any modification in the machine. To achieve the proposed objective, a cinematic study of curved blades was developed and was also conducted laboratory and field experiments. The basecutter discs are subject to two basic movements, rotation and translation (advancement of the harvester). The cinematic study describes these movements in form of matrices and some programs were written using the MATLAB software and this virtual simulation was used to investigate alternative basecutting configurations and provide knowledge to a theoretical development of the sugarcane cutting process. At the laboratory it was built a test rig that simulates the rotation and translation movements of the disc to cut a sample of sugarcane stalk. Two experiments were conducted: in the first, it was used a factorial statistics design which assessed the pitch of the serration, the horizontal blade angle (backward and forward) and cutting speed. It was analyzed the damage to stem, mass 4 losses, forces and cutting energy. In the second experiment the sample of whole sugarcane was submitted to a bending stress to simulate the effect of deflection roll and it was analyzed the damage to stem, mass loss and consumed energy... (Complete abstract click electronic access below) / Doutor

Este trabalho tem como objetivo analisar a influencia da configuração física do sistema de espalhamento de palha em colheitadeira de grãos na eficiência do espalhamento da palha, visando cobertura mais uniforme do solo de cultivo. Tal processo produzirá melhoramentos no próximo plantio, pois espalhamento mais uniforme de palha evita perdas de nutrientes do solo por incidência luz solar, assim como previne erosão hídrica e eólica. Para analisar a influencia dos parâmetros da configuração física do sistema espalhador de palha foram realizados testes alterando parâmetros como quantidade de pás, ângulo de pás, rotação dos rotores, diâmetro dos rotores, defletor central e vazão de material. Devido à importância econômica no cenário nacional e mundial, utilizou-se a cultura de soja e os testes foram realizados em laboratório seguindo as normas da Sociedade Americana de Engenheiros Agrícolas e Biológicos (ASAE). O trabalho visa fornecer dados que auxiliem designers no desenvolvimento de novos projetos de gerenciamento de resíduos, de modo que venham a aumentar a eficiência desses sistemas, contribuindo com o crescimento da agricultura em no país. Os resultados apontam que a geometria do defletor central apresenta o parâmetro de maior influencia na uniformidade de cobertura da palha ao solo. / The objective of this work is to analyze the influence of the physical configuration of the straw spread system in grain harvester on the efficiency of the straw spread, aiming at a more uniform coverage of the crop soil. This process will produce improvements in the next planting, because more uniform straw spread prevents soil nutrient losses by sunlight, as well as prevent water and wind erosion. In order to analyze the influence of the parameters of the physical configuration of the straw spreader system, tests were performed changing parameters such as blade quantity, blade angle, rotor rotation, rotor diameter, central deflector and material flow. Due to the economic importance in the national and world scenario, the soybean crop was used and the tests were carried out in laboratory according to the standards of the American Society of Agricultural and Biological Engineers (ASAE). The work aims to provide data to assist designers in the development of new waste management projects, so that they will increase the efficiency of these systems, contributing to the growth of agriculture in the country. The results indicate that the geometry of the central baffle presents the parameter of greatest influence on the uniformity of covering of the straw to the soil.

The aim of this thesis was to compare the activity and quality of work of the combine harvester New Holland CR 9080 and John Deere 9880 STS at harvest of cereals and oilseed rape and their simple economic evaluation. The thesis was focused on comparing losses and influence of moisture of harvested crops on the size of the losses, on the quality of crushing and the spreading of plant residues. Then the inf luence of moisture of harvested crops on the quality of crushing and the spreading of plant residues, analysis of performance and consumption of diesel were compared.