O preço atual do minério de ferro obrigou as empresas a reduzirem os custos operacionais na fase mina. O carregamento e transporte de materiais com utilização de escavadeiras e caminhões grande porte representam grande parcela do custo total, particularmente com pneus, diesel, manutenção e mão de obra. Metas de movimentação anual são divididas durante os meses e as condições climáticas podem influenciar na produtividade e desempenho dos equipamentos. O banco de dados da movimentação mensal está condicionado com a capacidade de cada caminhão. Cada frota possui o payload característico e este representa a capacidade de transporte, sendo o valor da massa transportada o único parâmetro extraído em cada ciclo, sem considerar o posicionamento do material sobre a caçamba dos equipamentos. Forças de cisalhamento e torção são aplicadas constantemente no chassi e pneus dos caminhões e, quando as cargas estão descentralizadas, potencializam estes eventos. O transporte de cargas descentralizadas agride os pneus diminuindo a vida útil causando danos como deslocamento da banda de rodagem e separação do flanco. Este trabalho teve como objetivo diminuir as ocorrências de cargas descentralizadas e os custos operacionais. Para incrementar o posicionamento do material sobre as caçambas, a telemetria foi a ferramenta utilizada. Análises de pressões de suspensões indicam o posicionamento das cargas e através desses valores foi criado um banco de dados. Este banco de dados pode indicar qual operador de carga precisa de reciclagem, contribuindo para a redução de cargas descentralizadas e custos, uma vez que cargas deste perfil sucateiam precocemente pneus e suspensões. O estudo foi realizado em Itabira, em uma mina de minério de ferro a céu aberto. A metodologia comprovou ser capaz diminuir as ocorrências de cargas descentralizadas assim como aumentar a vida útil de pneus. Uma possível economia foi apresentada para ano de 2014, período em que a média das horas trabalhadas de pneus ficou abaixo da meta aumentando os custos fase mina. / The actual iron ore price forces the companies to reduce costs in all production steps of the mining operation. Loading and hauling materials using shovel-truck system represents the highest mining costs, particularly tires, diesel, maintenance and workforce. Annual goals of materials movement are split by months were weather conditions can affect productivity and performance of the fleet. The data file of the monthly material movement is based on the scale of each truck. Every fleet has a payload and it represents the capacity of hauling, being the value of loading a unique input extracted in each duty cycle, without taking into account the position of the material over the truck’s dump. Shear forces and torsion are applied all time at the frames trucks and, when the truckloads are unbalanced, increases the forces over the frame and tires. Transport unbalanced truckloads into long distances attack the tires and decrease its end of life, causing damages like displacement of tread and flank separation. The objective of this study is to propose a methodology to decrease unbalanced truck loads reducing the mining costs. In this mission of incorporating a material position on the truck´s dump, the telemetry was taking into consideration. The analysis of the suspension pressures data values shows the truckloads positions and with this data was created a databank. This databank indicates that the operators need truck load training to reduce unbalanced loads and truck costs in the mining operation, since unbalanced loads leads to early tires and suspensions scrap. The case study was carried out at Itabira Iron Ore Mine Complex, Brazil. This methodology was able to reduce the number of unbalanced truck loads as well as the tires life was increased. An economic saving estimate is presented based on 2014 scrapped tires data bank, in this year the tires life cycle was underneath, burdening operational costs.

O motivo da dissertação “Desenvolvimento de um Modelo de Dimensionamento de Equipamentos de Escavação e de Transporte” surgiu da necessidade de apoiar no processo de decisão de dimensionamento dos principais equipamentos de mineração. Este trabalho apresenta um modelo simples e direto para dimensionar os equipamentos principais de mineração (escavadeiras e caminhões) através de uma rotina criada denominada EXCEsimulator, concebido para o cálculo da capacidade das caçambas das escavadeiras, do número dos equipamentos de escavação e de transporte, bem como os tempos de espera das unidades de transporte em carregar. Para tal, definem-se os parâmetros de produtividade e caraterísticas dos equipamentos; calcula-se aplicando um modelo determinístico de produção; e faz-se o levantamento de equipamentos existentes no mercado, reunindo as suas características e serviços prestados pelos representantes ou fabricantes das marcas. Para demostrar a funcionalidade do modelo desenvolvido, o presente trabalho demonstrou, através de um estudo de caso, o dimensionamento de uma frota de carregamento e transporte para uma mineração a céu aberto utilizando indicadores de produção, e uma comparação entre o uso de equipamentos de pequeno e grande porte no aspeto da demanda de equipamento. O estudo foi desenvolvido a partir de uma empresa de mineração hipotética baseada em dados realista. O modelo desenvolvido é aplicável a qualquer tipo de equipamento de escavação e de transporte, independente do seu porte e capacidade de produção. Como conclusão, pretende-se com esta dissertação fornecer uma ferramenta útil para o apoio à decisão de dimensionamento de equipamentos e frotas de escavação e de transporte capaz de suprir a necessidade de uma consulta de mercado. / The reason for the dissertation "Development of an Estimating Model for Excavation and Transport Equipment" arose from the need to support the decision-making process for the size of the main mining equipment. This work presents a simple and direct model for sizing the main mining equipment (excavators and trucks) through a routine created called EXCEsimulator, designed to calculate the capacity of excavator buckets, number of excavation and transport equipment, and As the waiting times of the transport units on loading. For this, the parameters of productivity and characteristics of the equipment are defined; Is calculated by applying a deterministic model of production; And it is made the survey of existing equipment in the market, gathering its characteristics and services provided by the representatives or manufacturers of the brands. To demonstrate the functionality of the developed model, the present study demonstrated, through a case study, the design of a loading and transport fleet for open pit mining using production indicators, and a comparison between the use of small equipment And large in the aspect of equipment demand. The study was developed from a hypothetical mining company based on realistic data. The developed model is applicable to any type of excavation and transportation equipment, regardless of its size and production capacity. In conclusion, it is intended with this dissertation to provide a useful tool to support the decision on sizing equipment and excavation and transport fleets capable of supplying the need for a market consultation.

Introducing an electric thermostat to the thermal management system is a way of actively controlling the temperature of the engine, which has been shown to have several possible gains regarding power, fuel consumption, emissions and engine durability. Complexity, cost and durability are key concerns that have led to no heavy duty truck on the market having an electrically controllable thermostat. This emphasizes the need for exploring alternative solutions that enables electric control of the thermostat according to the needs of heavy commercial vehicles. Several concepts have been generated to solve this problem and a model based approach in Simulink, Matlab and GT Suite was used for the development and evaluation. The most promising concept of combining a BLDC electric motor with a wax body enables electric control with a downsized actuator and full fail-safe function while showing improvements in temperature control performance compared to a traditional wax thermostat. This thesis has increased the knowledge on the subject and could allow for implementing an electrically controlled thermostat in future Scania heavy duty trucks, leading to a more durable engine with lower fuel consumption and emissions.

Este trabalho apresenta um modelo para a verificação do trem-tipo de projeto de pontes e viadutos da norma brasileira a partir do tráfego real nas estradas. Inicialmente, apresenta-se a comparação da carga móvel da norma brasileira com o Eurocode e com as normas da AASHTO. Em seguida, apresenta-se o estado da arte no Brasil e no mundo em pesquisas na área de cargas móveis em pontes. Propõe-se um modelo de verificação do trem-tipo baseado em simulações das passagens e cargas de veículos, através do método de Monte Carlo. São utilizados dados de pesagem e de quantidades de veículos provenientes de uma rodovia concedida à iniciativa privada no interior paulista. São efetuadas análises de pontes celulares com diversos vãos, de 30 a 200 metros, sendo estudados os momentos fletores no meio do vão e forças cortantes adjacentes aos apoios, em obras isostáticas, e momentos fletores no apoio central de pontes contínuas de dois vãos. É dada maior ênfase às situações de congestionamento sobre a ponte, e são efetuadas extrapolações estatísticas para a obtenção dos esforços característicos, levando-se em conta as diferentes situações de tráfego possíveis. Por fim, é feita uma extensão ao estudo das grelhas, utilizando-se linhas de influência transversais em ponte com vão de 30 metros, sem transversinas intermediárias. / This work presents a model to verify the design traffic load model of the Brazilian code, based on real traffic at road bridges. First, it compares Brazilian load model with Eurocode 1 and AASHTO Standard and LRFD Specifications. Then, recent development and research on bridge traffic load models are presented, in Brazil and other countries. A verification model of the traffic load is proposed, based on quantity and weight vehicle simulations, using Monte Carlo method. Real traffic data of trucks, used in this work, have been collected at highways of Sao Paulo state. Box-girder bridges from 30 to 200 m spans are investigated, studying the bending moment at midspan and the shear forces near the supports, on simply supported bridges, and the bending moment at center support, on two-span continuous bridges. Traffic jam situations on the bridge are emphasyzed, and statistical extrapolations to the load effects carachteristic values are done. Finally, it presents an extension of this study to multi-beam cross sections, using transverse influence lines, in a 30 m span bridge, without transverse beams.

Orientador: Pablo Siqueira Meirelles / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T13:17:01Z (GMT). No. of bitstreams: 1 Mognon_RicardoJose_M.pdf: 6522567 bytes, checksum: c295d49c72243d82eac24226d8523fc7 (MD5) Previous issue date: 2011 / Resumo: Este projeto tem por objetivo estudar um problema de rigidez estrutural de cabina para caminhões e também da trinca de parabrisas laminados devido às forças dinâmicas geradas pelas suspensões de cabinas e chassis em caminhões pesados e extra-pesados. Essa análise será feita, inicialmente, através da validação dos modelos não lineares de amortecimento, molas helicoidais, barras estabilizadoras, bolsões de ar, feixes de molas e coxins utilizados pelas ferramentas computacionais comerciais para simulação dinâmica de sistemas multicorpos ADAMS/CAR, cujos resultados serão comparados aos obtidos por meio de aquisição de sinais experimentais em campo para sua validação. Análises de elementos finitos serão realizadas para verificar áreas críticas ao redor do parabrisa que justifiquem suas quebras. Tais resultados mostraram que a suspensão traseira de chassis está absorvendo pouca energia devido à falta de amortecedores, barra estabilizadora e um feixe de mola mais adequado, acarretando em um aumento na vibração da cabina. Também se constatou que a suspensão dianteira da cabina foi desenvolvida com um coeficiente de amortecimento abaixo do necessário, causando o final de curso em frenagem ou onde as condições de pista possuem muitos obstáculos ou desníveis. Os dois fatores descritos acima reduzem sensivelmente a vida útil dos componentes da suspensão da cabina que, em conjunto com as tensões residuais da variação do processo de fabricação e montagem, reduzem ainda mais a vida útil do parabrisa colado na estrutura da cabina, tornando-o mais sensível a qualquer deformação. Desta forma, uma nova barra estabilizadora para a suspensão da cabina foi desenvolvida reduzindo as forças dinâmicas principalmente laterais, a transmissibilidade e as deformações estruturais na cabina, assim como também culminou na melhoria da qualidade de fabricação, controle e montagem dos parabrisas / Abstract: This project aims to study a problem of structural stability for trucks and also cracks on laminated windscreens due to the dynamic forces of cab & chassis suspensions on heavy & extra heavy trucks. This analysis will be done through the validation of nonlinear damping models, coil springs, antiroll bars, air springs, leaf springs and bump stops using the commercial software tool for dynamic simulation of multibody systems ADAMS/CAR whose results will be compared to those taken by experimental signal acquisitions in the field and finite element analysis by software ABAQUS to find out critical areas around the windscreen in order to explain the cracks. Such results showed that the rear chassis suspension is absorbing low energy due to the lack of shock absorbers, antiroll bar and a correct leaf spring more appropriate, resulting in an increasing in the vibration of the cab. It also found that front cab suspension was developed with a lower damping coefficient what is always necessary to avoid the end of cab suspension stroke on breaking or on track conditions which have many obstacles or unevenness. Both factors mentioned above significantly decrease the lifetime of cab suspension components which together with the residual strengths of production process & assembly decrease even more the lifetime of bonded windscreen on cab structure that more sensitive to any cab deformation. Thus, a new antiroll bar to cab suspension was developed mainly by decreasing the dynamics forces, the transmissibility and the cab structural deformations and also resulted in the improvement of production process, control and assembly of the windscreens / Mestrado / Dinâmica / Mestre em Engenharia Automobilistica

In an ever-changing industry where competition between actors is growing, technical improvements and investments can be a way to outperform competitors and gain competitiveadvantages. In a relatively under-developed industry, technological developments may leadto major improvements and change the layout of the whole business. Purpose – The main purpose of this thesis is to investigate potential cost reductions obtained by autonomous vehicles within the Swedish logistics industry. Studying opportunities for companies tostrengthen their competitive advantage can create new markets, chances or ensure a strongmarket position. To investigate said opportunities, the following research questions werestated: What is the actual cost of implementing an autonomous vehicle? Which costs will be affected by an implementation of autonomous vehicles? How do these costs impact the Swedish logistics market seen from a cost perspective? Method – The data necessary to answer the questions was collected from document studies, literature studies and interviews. These were carried out simultaneously in an iterativeprocess. Moreover, a pragmatic philosophy was undertaken, together with an abductive approach. The data was compared with existing theory by pattern matching and analysed withthematic approach, in order to ensure the level of trustworthiness. Findings/Implications – The findings of this thesis is that autonomous vehicles willheavily impact the logistics industry. By gradually implementing autonomous vehicles, theSwedish logistics sector can save upwards of 13,4 billion SEK between 2020 and 2030.This shift towards autonomous vehicles will move jobs from the long haul sector to urbanlogistics and telecommunications. Additionally, the society will see great benefits as 90% ofall traffic accidents will not happen when all vehicles are autonomous. It is clear that theSwedish logistics industry will benefit from an implementation of autonomous vehicles.Simultaneously it will also be beneficial for the society and the Swedish welfare. Limitations – The major limitation of this thesis is the time horizon. Because of being future oriented, much data was based on external estimations that might change over time.Moreover, only costs directly connected to transportations has been investigated, leavingroom for further studies related to indirect costs, as well as the organizational impacts onfuture supply chains.

Every year over 1.35 Million lives are lost to road accidents. Trucks are probably the most dangerous vehicles on public roads due to their size and mass. 15% of all accidents involve trucks and the majority of victims are car occupants. Most of these accidents happen outside of urban areas at high speeds. In the dawn of autonomous drive and electromobility the trucking industry has the opportunity to reinvent their products. Volvo Trucks is a company that has Safety in its DNA. Future Volvo trucks could be tailored around Safety to save lives and bring justice to this core value. Autonomy has the potential to make road accidents history in the long run. Before that becomes a reality, society will face a transitioning period where autonomous vehicles will share the space with manually driven vehicles. Communication between human and machine will be more important that ever. Product Designers must account also for situations where an accident is unavoidable. The focus of this project is to explore what safety means for the human eye. How do we perceive safety visually and how do we create trust? Trucks are versatile products built with modularity in mind. Manufacturers are responsible for delivering a capable tractor unit. Trailers and other accessories are built externally. Throughout the process of this project a holistic approach was adopted. The only way to have full control over the product experience is to design a complete product: trailer and tractor unit. Volvo Trucks experts are consulted along the way covering key points of interest such as Passive Safety, User Experience Design and Aerodynamics. Benchmarking of existing concepts sets a starting point. Initial explorations question the architecture of conventional trucks. Different set-ups and layouts are proposed. Each decision is made based on various safety needs of the future semi-autonomous traffic. Analog sketches and digital renderings of design proposals build the way towards a key sketch. The chosen design direction is further developed and built in CAD. The vehicle is designed with an eye on its environment. The link between truck and car, truck and human is the core of this project. This vehicle sheds light on the mystery of how autonomous vehicles will blend with traffic as it is known today. Focusing on long haul highway routs Volvo VISE is designed to execute hub to hub transport services autonomously. Signals used to communicate in road traffic are translated to the digital age. By being able to understand its environment and react to it, Volvo VISE comes to life with a soul of its own. Through various sensors and autonomous technology the vehicle measures each traffic situation and earns the trust of its surroundings through clear communication of intent. With soft and generous shapes the exterior design describes a friendly vehicle that wins over its audience at the first glance. Volvo VISE has a deeper understanding of safety. Beneath the skin and besides its capability to communicate, the vehicle is equipped with several passive safety features, taking control in every situation. Volvo VISE ensures road safety for all.

Air pollution is a threat to the environment and human health. Freight trucking in particular is the main source of freight transportation emissions. Heavy-duty trucks emit large amounts of toxic air pollutants that cause serious diseases and harm public health. In addition, heavy-duty trucks emit great amounts of greenhouse gas (GHG), which is the leading cause of global warming. Despite increased environmental restrictions on air pollution and rising trucking greenhouse gas emissions in the past decades, no economic study has examined the potential GHG and air pollution reductions in the trucking sector and the associated private abatement costs to the industry. This study accounts for GHG emissions and toxic air pollutants in measuring and evaluating efficiency and productivity for the trucking industry in the 48 contiguous states. Moreover, the private costs of abatement to the industry were also estimated. When only GHG was incorporated in the production model, the results showed that each state could expand desirable output and reduce GHG by an average of 11 percent per year between 2000 and 2007. The Malmquist-Luenberger productivity indexes showed that omitting or ignoring GHG in trucking service production yielded biased estimates. On the other hand, due to increased environmental regulations, most of the toxic air pollutants decreased dramatically between 2002 and 2005. The analytical results showed that inefficiency decreased during this period. The private costs of abatement averaged $73 million per state in 2005. When GHG and six toxic air pollutants were incorporated in the production model, the estimated private abatement cost was $76 million per state, which was equivalent to 0.7 percent of the industry output in 2005.

<div>The United States Environmental Protection Agency (EPA) is charged with pro-tecting human health and the environment. Part of this mission involves regulating heavy-duty trucks that produce particulate matter (PM), unburned hydrocarbons (UHC), carbon dioxide (CO2), and nitrogen oxides (NOx). A byproduct of lean burn combustion in diesel engines is NOx. NOx output limits from commercial vehicles have been reduced significantly from 10 g/hp-hr in 1979 to 0.2 g/hp-hr in 2010. Ad-ditional reductions are expected in the near future.</div><div><br></div><div>One pathway to meet future NOx emissions regulations in a fuel efficient manner is with higher performing exhaust aftertreatment systems through improved engine air handling. As exhaust aftertreatment’s capability to convert harmful NOx into harmless N2 and H2O is a function of temperature, a key performance factor is how quickly does the exhaust aftertreatment system heat up (warm-up), and how well does the system stay at elevated temperatures (stay-warm).</div><div><br></div><div>When the warm-up strategy of iEGR was implemented over the heavy duty federal test procedure (HD-FTP) drive-cycle, it was able to get the SCR above the critical 250◦C peak NOx conversion threshold 100 seconds earlier than the TM baseline. While iEGR consumed 2.1% more fuel than the TM baseline, it reduced predicted tailpipe NOx by 7.9%.</div><div><br></div><div>CDA implemented as a stay-warm strategy over the idle portions of the HD-FTP successfully kept the SCR above the 250◦C threshold for as long as the TM baseline and consumed 3.0% less fuel. Implementing CDA both at idle and from 0 to 3 bar BMEP consumed an additional 0.4% less fuel, for a total fuel consumption reduction of 3.4%.</div><div><br></div><div>A method to predict and avoid compressor surge (which can destroy turbochargers and in fact did so during the HD-FTP experiments) instigated by CDA was devel-oped, as discussed later, and implemented with staged cylinder deactivation to avoid compressor surge.</div><div><br></div><div>The literature does not consider the fidelity of road grade data required to ad-equately predict vehicle fuel consumption and operational behavior. This work ad-dresses this issue for Class 8 trucks by comparing predicted fuel consumption and operation (shifting, engine torque/speed, and braking) of a single Class 8 truck simu-lated with grade data for the same corridor from different sources. The truth baseline road grade (best fidelity available with LiDAR) was obtained previously. This work compares road grade data to the truth baseline from four other typical methods i) utilizing GPS to record horizontal position and vertical elevation, ii) logging the pitch of a cost effective, commercially available IMU, iii) integrating the horizontal and ver-tical velocities of the same IMU, and iv) a commercially available dataset (Comm). Comm grade data (R2=0.992) best matches the LiDAR reference over a 5,432 m stretch of US 231 where high quality LiDAR data was available, followed in quality by the integrated IMU velocity road grade (R2=0.979). Limitations of the Comm dataset are shown, namely missing road grade (decreased point density) for up to 1 km spans on other sections of US 231, as well as for Interstate 69. Vehicle simulations show that both the Comm data (where available and accurate) and integrated IMU road grade data result in fuel consumption predictions within 2.5% of those simulated with the truth reference grade data.</div><div><br></div><div>The simulation framework described in Chapter 6 combines high fidelity vehicle and powertrain models (from Chapter 5) with a novel production-intent platooning controller. This controller commands propulsive engine torque, engine-braking, or friction-braking to a rear vehicle in a two-truck platoon to maintain a desired following distance. Additional unique features of the framework include high fidelity road grade and traffic speed data. A comparison to published experimental platooning results is performed through simulation with the platooning trucks traveling at a constant 28.6 m/s (64 MPH) on flat ground and separated by 11 m (36 ft). Simulations of platooning trucks separated by a 16.7 m (54.8 ft) gap are also performed in steady-state operation, at different speeds and on different grades (flat, uphill, and downhill), to demonstrate how platooning affects fuel consumption and torque demand (propulsive and braking) as speed and grade are varied. For instance, while platooning trucks with the same 16.7 m gap at 28.6 m/s save the same absolute quantity of fuel on a 1% grade as on flat ground (1.00 per-mile, normalized), the trucks consume more fuel overall as grade increases, such that relative savings for the platoon average decrease from 6.90% to 4.94% for flat vs. 1% grade, respectively. Furthermore, both absolute and relative fuel savings improve during platooning as speed increases, due to increase in aerodynamic drag force with speed. There are no fuel savings during the downhill operation, regardless of speed, as the trucks are engine braking to maintain reasonable speeds and thus not consuming fuel. Results for a two-truck platoon are also shown for moderately graded I-74 in Indiana, using traffic speed from INDOT for a typical Friday at 5PM. A 16.7 m (54.8 ft) gap two-truck platoon decreases fuel consumption by 6.18% over the baseline without degradation in trip time (average speed of 28.3 m/s (63.3 MPH)). The same platooning trucks operating on aggressively graded I-69 in Indiana shows a lower platoon-average 3.71% fuel savings over baseline at a slower average speed of 24.5 m/s (54.8 MPH). The impact of speed variation over, and grade difference between, these realistic routes (I-74 & I-69) on two-truck platooning is described in detail.<br></div><div><br></div>

Autonomous vehicles is a rapidly expanding field, and promise to play an important role in society. In more isolated environments, vehicle automation can bring significant efficiency and production benefits and it eliminates repetitive jobs that can lead to inattention and accidents. The thesis addresses the problem of lateral and longitudinal dynamics control of autonomous ground vehicles with the purpose of accurate and smooth path following. Clothoids are used in the design of optimal predictive controllers aimed at minimizing the lateral forces and jerks in the vehicle. First, a clothoid-based path sparsification algorithm is proposed to efficiently describe the reference path. This approach relies on a sparseness regularization technique such that a minimal number of clothoids is used to describe the reference path. Second, a clothoid-based model predictive controller (MPCC) is proposed. This controller aims at producing a smooth driving by taking advantage of the clothoid properties.  Third, we formulate the problem as an economic model predictive controller (EMPC). In EMPC the objective function contains an economic cost (here represented by comfort or smoothness), which is described by the second and first derivatives of the curvature.  Fourth, the generation of feasible speed profiles, and the longitudinal vehicle control for following these, is studied. The speed profile generation is formulated as an optimization problem with two contradictory objectives: to drive as fast as possible while accelerating as little as possible. The longitudinal controller is formulated in a similar way, but in a receding horizon fashion. The experimental evaluation with the EMPC demonstrates its good performance, since the deviation from the path never exceeds 30 cm and in average is 6 cm. In simulation, the EMPC and the MPCC are compared with a pure-pursuit controller (PPC) and a standard MPC. The EMPC clearly outperforms the PPC in terms of path accuracy and the standard MPC in terms of driving smoothness. / <p>QC 20160503</p> / iQMatic