O objetivo desta dissertação foi estudar dispositivos para contenção de veículos desgovernados por falta de freios em declives longos e íngremes. Para tanto, fez-se uma revisão abrangente da literatura especializada e coletaram-se dados em testes realizados na área de escape construída no km 42,7 da pista sul da Via Anchieta, onde existe um declive de 12,8 km de extensão. A pesquisa relatada nesta dissertação focaliza três aspectos principais: a eficiência do dispositivo em deter caminhões sem freios, a localização do dispositivos e a determinação da velocidade segura de operação de caminhões nesse declive. Dados empíricos da desaceleração dos caminhões no dispositivo foram coletados com auxílio de GPS, o que permitiu estudar o comportamento dos caminhões dentro da caixa de retenção. Os dados coletados foram usados para a calibração de um modelo capaz de estimar a desaceleração média proporcionada pelo dispositivo em função da velocidade de entrada e do número de eixos do caminhão. Para a análise da localização do dispositivo, propôs-se um modelo que leva em consideração o perfil vertical do declive, a velocidade dos caminhões, a temperatura dos freios e a frequência de acidentes com veículos desgovernados ao longo do declive. A determinação da estratégia ótima de condução no declive consistiu em determinar a máxima velocidade que os caminhões podem percorrer o declive sem que os freios sofram superaquecimento. Os parâmetros usados na análise foram a massa bruta total do veículo e as reduções da sua caixa de câmbio. Foram estabelecidas velocidades e marchas máximas para 16 tipos de caminhão. Os resultados obtidos mostram que este tipo de dispositivo é capaz de deter caminhões desgovernados com segurança e podem subsidiar projetos de novas áreas de escape no Brasil. / The objective of the dissertation was to study devices for arresting runaway trucks on long and steep downgrades. A comprehensive review of the literature was carried out and empirical data were collected by means of real life trials at an arrester bed build at a 12.8 km downgrade on the southward lanes of Via Anchieta, the old highway connecting the cities of São Paulo and Santos, in Brazil. The research reported focused on three major aspects: arresting capability of the escape area, location of the escape area and safe operating speeds for trucks on this downgrade. Truck deceleration data were collected during the trials by means of GPS equipment installed in the vehicles and were used to determine truck behavior within the arrester bed. A mathematical model, which allows the estimation of average deceleration as a function of entry speed and number of axles, was fitted to the observed data. The location study proposed a method to establish the points along the downgrade where arrester beds are needed, based on road profile, truck speed, brake temperature and accident data. Optimal driving strategies for truck drivers to negotiate safely the downgrade were also studied, in order to determine the downgrade maximum speed that would avoid brake overheating. The parameters used in this analysis were gross vehicle mass and gearbox characteristics. Safe maximum downgrade speeds and gears were established for 16 truck models. The results, which showed that arrester beds are capable of safely stopping runaway trucks in long and steep downgrades, may also be used to assist the design of new arrester beds in Brazil.

O objetivo desta dissertação foi estudar dispositivos para contenção de veículos desgovernados por falta de freios em declives longos e íngremes. Para tanto, fez-se uma revisão abrangente da literatura especializada e coletaram-se dados em testes realizados na área de escape construída no km 42,7 da pista sul da Via Anchieta, onde existe um declive de 12,8 km de extensão. A pesquisa relatada nesta dissertação focaliza três aspectos principais: a eficiência do dispositivo em deter caminhões sem freios, a localização do dispositivos e a determinação da velocidade segura de operação de caminhões nesse declive. Dados empíricos da desaceleração dos caminhões no dispositivo foram coletados com auxílio de GPS, o que permitiu estudar o comportamento dos caminhões dentro da caixa de retenção. Os dados coletados foram usados para a calibração de um modelo capaz de estimar a desaceleração média proporcionada pelo dispositivo em função da velocidade de entrada e do número de eixos do caminhão. Para a análise da localização do dispositivo, propôs-se um modelo que leva em consideração o perfil vertical do declive, a velocidade dos caminhões, a temperatura dos freios e a frequência de acidentes com veículos desgovernados ao longo do declive. A determinação da estratégia ótima de condução no declive consistiu em determinar a máxima velocidade que os caminhões podem percorrer o declive sem que os freios sofram superaquecimento. Os parâmetros usados na análise foram a massa bruta total do veículo e as reduções da sua caixa de câmbio. Foram estabelecidas velocidades e marchas máximas para 16 tipos de caminhão. Os resultados obtidos mostram que este tipo de dispositivo é capaz de deter caminhões desgovernados com segurança e podem subsidiar projetos de novas áreas de escape no Brasil. / The objective of the dissertation was to study devices for arresting runaway trucks on long and steep downgrades. A comprehensive review of the literature was carried out and empirical data were collected by means of real life trials at an arrester bed build at a 12.8 km downgrade on the southward lanes of Via Anchieta, the old highway connecting the cities of São Paulo and Santos, in Brazil. The research reported focused on three major aspects: arresting capability of the escape area, location of the escape area and safe operating speeds for trucks on this downgrade. Truck deceleration data were collected during the trials by means of GPS equipment installed in the vehicles and were used to determine truck behavior within the arrester bed. A mathematical model, which allows the estimation of average deceleration as a function of entry speed and number of axles, was fitted to the observed data. The location study proposed a method to establish the points along the downgrade where arrester beds are needed, based on road profile, truck speed, brake temperature and accident data. Optimal driving strategies for truck drivers to negotiate safely the downgrade were also studied, in order to determine the downgrade maximum speed that would avoid brake overheating. The parameters used in this analysis were gross vehicle mass and gearbox characteristics. Safe maximum downgrade speeds and gears were established for 16 truck models. The results, which showed that arrester beds are capable of safely stopping runaway trucks in long and steep downgrades, may also be used to assist the design of new arrester beds in Brazil.

This thesis is aimed at studying the open pit truck- shovel haulage systems using computer simulation approach. The main goal of the study is to enhance the analysis and comparison of heuristic truck dispatching policies currently available and search for an adaptive rule applicable to open pit mines. For this purpose, a stochastic truck dispatching and production simulation program is developed for a medium size open pit mine consisting of several production faces and a single dump site using GPSS/H software. Eight basic rules are modeled in separate program files. The program considers all components of truck cycle and normal distribution is used to model all these variables. The program asks the user to enter the number of trucks initially assigned to each shovel site. Full-factorial simulation experiments are made to investigate the effects of several factors including the dispatching rules, the number of trucks operating, the number of shovels operating, the variability in truck loading, hauling and return times, the distance between shovels and dump site, and availability of shovel and truck resources. The breakdown of shovel and trucks are modeled using exponential distribution. Three performance measures are selected as truck production, overall shovel utilization and overall truck utilizations. Statistical analysis of the simulation experiments is done using ANOVA method with Minitab software. Regression analysis gives coefficient of determination values, R2, of 56.7 %, 84.1 %, and 79.6 % for the three performance measures, respectively. Also, Tukey&rsquo / s method of mean comparison test is carried out to compare the basic dispatching rules. From the results of statistical analysis, it is concluded that the effects of basic truck dispatching rules on the system performance are not significant. But, the main factors affecting the performances are the number of trucks, the number of shovels, the distance between the shovels and dump site, finally the availability of shovel and truck resources. Also, there are significant interaction effects between these main factors. Finally, an adaptive rule using the standardized utilization of shovels and trucks is developed.

Orientador: Antonio Celso Fonseca de Arruda / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-13T03:10:22Z (GMT). No. of bitstreams: 1 Mariolani_JoseRicardoLenzi_D.pdf: 4176852 bytes, checksum: 167bdeef2aec084118559b01ce0a899c (MD5) Previous issue date: 2009 / Resumo: Milhares de pessoas morrem por ano em todo o mundo em conseqüência da falta de párachoques adequados nas traseiras dos caminhões. Na tentativa de reverter essa situação, iniciou-se um trabalho de cooperação entre UNICAMP, Mercedes-Benz do Brasil e General Motors do Brasil cujos objetivos principais foram os de denunciar a Resolução CONTRAN No. 805/95 como ineficaz, projetar, construir e testar pára-choques confiáveis e apresentar soluções às autoridades governamentais. Para isso sugeriram-se os requisitos mínimos necessários ao projeto de um pára-choque eficaz, o qual deveria idealmente resistir ao impacto de um hipotético veículo "médio" a 50 km/h, projetou-se e construiu-se um pára-choque articulado com base nos requisitos sugeridos e realizaram-se dois crash tests, com o novo pára-choque articulado e com um pára-choque construído de acordo com a Resolução CONTRAN No. 805/95. O pára-choque articulado foi capaz de evitar a penetração do automóvel sob o caminhão, o que não ocorreu com o outro. Os resultados obtidos e os requisitos de projeto sugeridos formaram a base de uma nova norma brasileira referente à matéria, a qual se tornou a Resolução CONTRAN No. 152/03 e introduziu, na data de sua publicação, avanços inéditos em relação à proteção dos ocupantes de passageiros em colisões contra a traseira de caminhões. / Abstract: Because of the lack of effective rear underride guards attached to trucks, trailers and semitrailers, rear underride crashes are responsible for thousands of deaths every year throughout the world. Trying to reverse this situation, cooperative work was started between University of Campinas, Mercedes-Benz do Brasil and General Motors do Brasil, whose main goals were to denounce the Brazilian regulation CONTRAN no. 805/95 as ineffective, to design, construct and test a reliable underride guard and to present solutions to government authorities. To meet these goals, design parameters considered being the minimum essential requirements for effective underride guards, which ideally should be able to resist an impact of a hypothetical "average" car at 50 km/h, have been proposed. A new retractile underride guard has been designed according to the proposed parameters and crash tests have been carried out with the retractile guard and with another constructed according to regulation CONTRAN no. 805/95. The retractile guard could avoid underride, but the other could not. Based on these results and on the proposed design parameters, a new Brazilian standard for rear underride guards has been elaborated. This standard became later the new regulation CONTRAN no. 152/03 and introduced, at the date of issuing, the utmost in safety requirements concerning protection against underride. / Doutorado / Materiais e Processos de Fabricação / Doutor em Engenharia Mecânica

In the traffic domain it is commonly known that sleepiness is a highlycontributing factor in traffic accidents. Research has shown that sleepinessamong drivers is present in about 16-23 % of all car accidents. In the aviation andrailway industry a method or framework with some shared influences from theHuman Factors approach, called Fatigue Risk Management (FRM) has been usedto investigate how social and organisational factors affect the personnel’s level ofsleepiness. The overall aims of this study are to investigate how truck drivers’experience, fight and counteract sleepiness in their daily work environment. Theresults show that drivers face a wide variety of sleep contributing factors,stemming from both organisational factors and individual behaviour. Possibleways of counteracting truck driver sleepiness, concerning both the individual andthe organisation, are also suggested.

This thesis deals with a truck transport and with influence economic crisis on truck transport. The theoretical part is specialized in the truck transport in general, in the highways and toll in the Czech Republic, in the transporters' association, in international contracts and in the characteristic of truck transport management. The practical part deals with a choosen transport firm and with influence economic crisis on this choosen firm.

The increase in truck traffic on highways has brought many problems and challenges to transportation planning and traffic operation, including traffic congestion, transportation system deficiency (insufficient truck parking, etc.), safety, infrastructure deterioration, environmental impacts (air quality and noise), economic development, and so forth. Along with the increase in truck traffic, the need for developing a statewide truck freight demand model has grown so that a state can estimate truck traffic at any point on its highways. The most significant hurdle to including freight transportation in the transportation modeling process is that most of the demand forecasting methodologies currently available were developed for passenger trips, not freight trips. This type of modeling methodology usually makes an assumption that freight trips follow the same behavioral mechanism as passenger trips. In order to overcome the weakness of using a typical four-step demand forecasting modeling process, the concept of commodity flow models (CFMs) can be used to develop a truck freight flow model. It is widely accepted that focusing on the freights enables CFMs to capture more accurately the fundamental economic mechanisms that drive freight movements. The type of commodity being carried is one of the most important characteristics of truck movements, and it is sometimes a challenge to obtain such information from the carriers. Thus, lately, the integration of the freight flow modeling and land use modeling has emerged as an alternate tool to estimate freight movements than the previously developed models. In this study, county-level multiple regression models relating land use to commodity flow were developed using a geographical information system and statistics. Then, a statistical/mathematical statewide commodity flow distribution model was developed by using a physical friction factor (physical distance), a statistical friction factor (Euclidean distance), and economic factors (differences of population and difference of employment among the counties). The commodity flow distributed among truck traffic analysis zones (TTAZs) by the statewide commodity flow distribution model were converted to truck trips and the resulting truck trips were assigned to Utah's truck routes using the all-or-nothing assignment procedure of TransCAD and a genetic algorithm. Truck freight data from the US Census Bureau's Commodity Flow Surveys, which have become available to the public for free via the Internet, enabled the development of a commodity flow based statewide truck freight demand model. It was found that the integration of the freight flow and land use data could be a practical method for modeling tuck traffic demand on state-wide truck routes although the current level of data availability on commodity flow and land use data still constrains the full capability of this type of modeling.

En följd av såväl politiska beslut som den ökade medvetenheten hos kunder är att efterfrågan av grönare teknik har ökat. Idag står andelen av laddbara personbilar för ungefär en tredjedel av alla nyregistrerade personbilar i Sverige. Det är inte bara personbilstillverkare som går igenom detta teknikskifte mot grönare teknik och smartare självkörande bilar, samma trend ses i lastbilsindustrin. Även fast kunderna i detta fall är andra företag som t.ex. stora åkerier finns det även här en stor efterfrågan på den nya tekniken. Det kan tyckas motstridigt att tillverka ett elfordon som både ska klara av att transportera tung last samtidigt som det ska kunna erbjuda en lång räckvidd. Självkörande lastbilar är något som Scania tillsammans med flera stora lastbilstillverkare jobbar med att utveckla. De utmaningar som finns för lastbilstillverkare gällande det autonoma skiljer sig från personbilstillverkare. Syftet med rapporten är att undersöka hur produktutvecklingsprocessen påverkas av teknikskiftet mot eldrivna, autonoma lastbilar. Inledningsvis genomfördes en litteraturstudie där tidigare kända teorier och studier inom relevanta områden undersöktes för att få en bättre förståelse för det nuvarande kunskapsläget. Därefter hölls tre stycken semistrukturerade intervjuer med personer från olika avdelningar med olika kompetenser från företag inom dels lastbilsindustrin, men även personbilsindustrin. Intervjuerna syftade till att samla så mycket information som möjligt kring de utmaningar som lastbilsindustrin står inför ur ett produktutvecklings perspektiv. Även de förändringar som skett i samband med teknikskiftet var av intresse under intervjuerna. Efter intervjuerna gjordes en sammanställning och en analys av det resultat som framkommit under studien. Resultatet visar att det har skett en stor förändring inom industrin på flera områden. Nya arbetsmetoder har implementerats för att korta ned ledtiderna och öka kvaliteten på produkterna. Det finns ett ökat behov av nya kompetenser inom branschen och det blir allt vanligare att anställa personal från hela världen som kan arbeta på distans. Vidare satsas det allt mer på att omskola befintlig personal. Resultatet visar även att antalet samarbeten har ökat och att det sker ett stort informationsutbyte mellan företag som båda jobbar med autonom teknik. / An increasing demand for greener technology has been forced through by political decisions, but also as a result of growing awareness amongst customers. Today, the proportion of rechargeable passenger cars accounts for about a third of all newly registered passenger cars in Sweden. It is not just passenger car manufacturers who are experiencing this shift towards greener technology and smarter autonomous cars. The same trend can be seen in the truck industry, even if the customers in this case are large hauliers. It may seem contradictory to manufacture a vehicle that must both be able to transport heavy loads and withstand long range. Scania, amongst other big truck manufacturers, has come a long way in developing autonomous trucks. The challenges of truck manufacturers differ from those of passenger car manufacturers regarding autonomous technology. This study will investigate how the product development process is affected by the shift in technologytowards electric, autonomous trucks.Initially, a literature study was conducted where previous theories and studies in relevant areas were examined in order to gain a better understanding of the current state of knowledge. Subsequently, three semi-structured interviews were held with people from different departments and with various competences from companies in both the truck and car industries. The aim of the interviews was to gather as much information as possible about the challenges facing the truck industry from the product development perspective. The changes that have taken place as a result of the technology shift were also of interest in the interviews. Afterwards, an analysis summary was made of the results that emerged during the study. The results show that there has been significant change in several areas within the industry. New working methods have been implemented to shorten lead times and increase the quality of the products. There is a growing need for new skills within the industry and it is becoming increasingly common to employ staff from all over the world who can work remotely. At the same time, more and more funding is going towards further training of existing staff. The results also show that the number of collaborations has increased and that there is a large exchange of information between companies that are in the autonomous technology business.

Background  Global warming caused by greenhouse gas emissions necessitates a decrease in carbon emission caused by the truck transport industry. To combat the threat of global warming, goals are being set up on a global, national and corporate level. These goals are putting pressure on logistics service providers to decrease the emissions within the truck transport industry. Implementation of green practices is found to be especially challenging within heavy truck transport due to weight and distance of the transport characteristics. In order to achieve emission reductions, logistics service providers are dependent on the alignment with their transport buyers, known as shippers to implement green logistics practices. Purpose The purpose of this study is to identify challenges and enablers for sustainable green transitions within heavy truck transports among shippers and logistics service providers. The study formulates two research question to help achieve the purpose, these questions are focused on challenges and enablers among both shippers and logistics service providers.  Method The study employs an explorative research approach in a multiple case study setting. Three configurations of shipper-LSP relationships are studied and analyzed through thematic analysis, the researchers also conducted a cross-case analysis to compare and identify similarities and differences between the cases in order to draw conclusions.  Conclusion A green transition within the heavy truck transport sector face numerous challenges. The challenges include a high dependency on vehicle development, lacking infrastructure, alignment issues between shippers and logistics service providers and trade off dilemmas. In order to overcome the issues findings, suggest that shippers and LSPs should focus on creating shared goals in order to facilitate implementation of green logistics practices and mitigate the challenges.

Driven by the goal of decreasing emissions and pollutants towards a more sustainable future, the automotive industry is undergoing a rapid transition towards battery-powered electric vehicles. This shift to sustainable transport is fast-paced, and new technical solutions are being offered on a regular basis to fulfil the future needs for electric vehicles, including battery-electric trucks. This continuously necessitates a fast development of the battery-electric truck, along with the cooling system. To validate the cooling system, Scania's preferred approaches are testing and 3D simulations. However, these approaches are time-consuming and cannot match the pace of the design or the development. This thesis addresses the implementation of using 1D Simulations (GT-Suite) to carry out coolant filling simulations as a more efficient approach by studying the filling of the battery cooling system in an electric truck and, later, validating the results obtained with a test rig. In this thesis, different cases were defined, each adding more complexity to the circuit, and the parameters studied were the filling times and the location of air traps. Finally, a case with a closed circuit and running a coolant pump was developed to study the possibilities of devising quicker deaeration techniques for the circuit. The work completed in this thesis may be used as an example of how filling simulations can be performed with GT-Suite. This thesis is a good starting point, exploring a vast potential in using 1D Simulations to simulate the coolant-air interaction in a cooling system. Nonetheless, the findings revealed that GT-Suite v2020 and v2021 lack a robust model to properly simulate the interaction of coolant and air in certain sections of the circuit. In addition, the simulation model failed to obtain a steady-state solution in some cases resulting in discrepancies between the results from the test rig and the simulations. In conclusion, it was found that 1D simulations are not an ideal way forward when individual components of the cooling circuit are being considered, for example, the cooling plates, but are much quicker and seem to be a promising method to get an overview on a system level. / Fordonsindustrin drivs av målet att minska utsläppen och föroreningarna mot en mer hållbar framtid och genomgår en snabb omställning mot batteridrivna elfordon. Övergången till hållbara transporter går snabbt och nya tekniska lösningar erbjuds regelbundet för att möta de framtida behoven av elfordon, inklusive batteridrivna lastbilar. Detta kräver kontinuerligt en snabb utveckling av den batteri-elektriska lastbilen, tillsammans med kylsystemet. För att validera kylsystemet är Scanias föredragna metoder testning och 3D-simuleringar. Dessa tillvägagångssätt är dock tidskrävande och kan inte matcha takten i designen eller utvecklingen. Denna avhandling behandlar implementeringen av att använda 1D-simuleringar (GT-Suite) för att utföra kylvätskefyllningssimuleringar som ett effektivare tillvägagångssätt genom att studera fyllningen av batterikylsystemet i en elektrisk lastbil och senare validera resultaten som erhållits med en testrigg. I denna avhandling definierades olika fall, var och en lägga till mer komplexitet till kretsen, och de undersökta parametrarna var påfyllningstiderna och platsen för luftfällor. Slutligen utvecklades ett fall med en sluten krets och kör en kylvätskepump för att studera möjligheterna att utforma snabbare deaerationstekniker för kretsen. Arbetet i denna avhandling kan användas som ett exempel på hur fyllningssimuleringar kan utföras med GT-Suite. Denna avhandling är en bra utgångspunkt och utforskar en enorm potential i att använda 1D-simuleringar för att simulera kylvätske-luftinteraktionen i ett kylsystem. Resultaten visade dock att GT-Suite v2020 och v2021 saknar en robust modell för att korrekt simulera interaktionen mellan kylvätska och luft i vissa delar av kretsen. Dessutom kunde simuleringsmodellen inte få en steady state-lösning i vissa fall vilket resulterade i skillnader mellan resultaten från testriggen och simuleringarna. Sammanfattningsvis konstaterades det att 1D-simuleringar inte är en idealisk väg framåt när enskilda komponenter i kylkretsen övervägs, till exempel kylplattorna, men är mycket snabbare och verkar vara en lovande metod för att få en översikt på systemnivå.