Detta arbete behandlar framtagandet av ett antal digitala konceptmodeller i CAD-programvaran CATIA, där lastväxlarmoduler med primärt fokus mot räddningstjänstens arbete behandlats. Modulerna är även applicerbara mot BAE Systems Hägglunds civila bandvagnssystem Beowulf. Framtagandet har skett i ett direkt samarbete med BAE Systems Hägglunds i Örnsköldsvik, samt civila myndigheter och räddningstjänsten i Umeå. Arbetets huvudinriktning har legat mot att optimera terrängförmågan för räddnings-tjänstens arbete med relevant utrustning, där skogsbrandsbekämpning använts som ett fokusområde på grund av dess förekomst i svår terräng. Framtagandet av konceptet grundar sig på intervjuer med yrkesverksam personal på civila myndigheter samt räddningstjänsten. Detta mynnade i ett antal CAD-modeller för konceptmoduler som bygger på en lastväxlare för att kunna ta med sig stora delar av den utrustningen som finns placerade i de skogsbrandsdepåer som MSB tillhandahåller. Detta arbete visar även på att Beowulf skulle erbjuda en exceptionell plattform och basmodul för att utökas med flertalet andra typer av moduler som bygger på lastväxlare, främst för att skapa en enhetlighet och ökad terrängförmåga till hela civilförsvaret. Arbetets resultat har enbart fokuserat på de tekniska detaljerna för konceptframtagandet, men sammanställningen av intervjuerna påtalar även att samtliga instanser är överens om att bandvagnsförmågan är en viktig förmåga och resurs att inneha för räddnings-tjänsten och civilförsvarets förmåga att verka i terräng, vilket skulle vara en aspekt att vidareutveckla i kommande arbeten som berör området. / This work presents the development of digital conceptual modules of a load changer unit with demountable modules in the CAD software CATIA. The primary focus of application was on the Swedish rescue services. The modules can be mounted on the BAE Systems Hägglunds tracked vehicle system Beowulf. The development process was conducted in direct cooperation together with BAE Systems Hägglunds located in Örnsköldsvik, civilian authorities and the rescue services in Umeå. The main focus of the work was on optimizing the terrain capability for the rescue service´s work with relevant equipment, mainly regarding forest fires, as they commonly occur in rough terrain. The development of the concept was based on interviews with professional staff at civilian authorities and the rescue service in Sweden, resulting in a number of conceptual models that make use of an existing load changer, and allow transporting the majority of the equipment located in the forest fire depots provided by MSB. The work also shows that Beowulf would offer an exceptional platform and base module to be expanded with other types of modules based on a load changer unit, mainly to create uniformity and increased terrain capability for the entire civilian defense. Although, the work only focused focused on the technical details of the concept development, the compilation of the interviews indicates that the all-terrain tracked vehicle capability is an important and valuable resource to possess for the rescue services and the entire civil defense. This aspect could be further developed in future work concerning the topic.

<p>A vehicle that carries a person sitting in a wheelchair has been rebuilt. The original vehicle was provided with a petrol engine, hydrostatic drive and a mechanical steering rod, making it noisy and hard to maneuver. The purpose with this project was to convert the vehicle to make it more environmental and easier to drive.A new design has been proposed where an electrical drive has replaced the noisy combustion engine and an electrical motor with joystick control has replaced the manual steering.</p><p>The project was divided into two parts. One mechanical part where the construction of the drive and steering were to be decided. The other part involved programming the microprocessor and implementation of all the necessary electrical for the control system of the vehicle. The rebuild of the machine to a complete electrical machine was successful and the performance is similar to the original construction but easier to drive, less noisy and more environmental.</p>

A vehicle that carries a person sitting in a wheelchair has been rebuilt. The original vehicle was provided with a petrol engine, hydrostatic drive and a mechanical steering rod, making it noisy and hard to maneuver. The purpose with this project was to convert the vehicle to make it more environmental and easier to drive.A new design has been proposed where an electrical drive has replaced the noisy combustion engine and an electrical motor with joystick control has replaced the manual steering. The project was divided into two parts. One mechanical part where the construction of the drive and steering were to be decided. The other part involved programming the microprocessor and implementation of all the necessary electrical for the control system of the vehicle. The rebuild of the machine to a complete electrical machine was successful and the performance is similar to the original construction but easier to drive, less noisy and more environmental.

Construction machines, also referred to as engineering vehicles or earth movers, are used in a variety of tasks related to infrastructure development and material handling. While modern construction machines represent a high level of sophistication in several areas, their suspension systems are generally rudimentary or even nonexistent. This leads to unacceptably high vibration levels for the operator, particularly when considering front loaders and dump trucks, which regularly traverse longer distances at reasonably high velocities. To meet future demands on operator comfort and high speed capacity, more refined wheel suspensions will have to be developed. The aim of this thesis is therefore to investigate which factors need to be considered in the fundamental design of suspension systems for wheeled construction machines. The ride dynamics of wheeled construction machines are affected by a number of particular properties specific to this type of vehicle. The pitch inertia is typically high in relation to the mass and wheelbase, which leads to pronounced pitching. The axle loads differ considerably between the loaded and the unloaded condition, necessitating ride height control, and hence the suspension properties may be altered as the vehicle is loaded. Furthermore, the low vertical stiffness of off-road tyres means that changes in the tyre properties will have a large impact on the dynamics of the suspended mass. The impact of these factors has been investigated using analytical models and parameters for a typical wheel loader. Multibody dynamic simulations have also been used to study the effects of suspended axles on the vehicle ride vibrations in more detail. The simulation model has also been compared to measurements performed on a prototype wheel loader with suspended axles. For reasons of manoeuvrability and robustness, many construction machines use articulated frame steering. The dynamic behaviour of articulated vehicles has therefore been examined here, focusing on lateral instabilities in the form of “snaking” and “folding”. A multibody dynamics model has been used to investigate how suspended axles influence the snaking stability of an articulated wheel loader. A remote-controlled, articulated test vehicle in model-scale has also been developed to enable safe and inexpensive practical experiments. The test vehicle is used to study the influence of several vehicle parameters on snaking stability, including suspension, drive configuration and mass distribution. Comparisons are also made with predictions using a simplified linear model. Off-road tyres represent a further complication of construction machine dynamics, since the tyres’ behaviour is typically highly nonlinear and difficult to evaluate in testing due to the size of the tyres. A rolling test rig for large tyres has here been evaluated, showing that the test rig is capable of producing useful data for validating tyre simulation models of varying complexity. The theoretical and experimental studies presented in this thesis contribute to the deeper understanding of a number of aspects of the dynamic behaviour of construction machines. This work therefore provides a basis for the continued development of wheel suspensions for such vehicles. / QC 20110531

Denna rapport ar resultatet av ett kandidatexamensarbete som avlades på KTH under våren 2018 i maskinkonstruktion. Uppdragsgivare var KTH och Skogforsk; det svenska skogsbrukets forskningsinstitut, som är finansierat av skogsnäringen och den svenska staten. Bakgrunden till projektet är de ökande kraven på ekologi och ergonomi i branchen, samt bristen på förare och operatörer. Uppgiften var att förbereda en skotare, modellXt28, för automation modellbaserat. En skotare är ett terrängfordon som används för att transportera rundvirke, stubbar och liknande. Då arbetet för att helt automatisera ett fordon är väldigt omfattande begränsades detta projekt till att fokusera på skotarens perception av omgivningen. Läsaren kommer få ta del av utformningen av en skyddande sensorenhet, anpassad för den krävande miljön. Krav för automation av fordon, val av sensorer och placering av dessa, möjliga lastfall, och infästningsmöjligheter behandlas. En utmaning under arbetets gång har varit bristen på tillgängligt tidigare liknande arbete, där kombinationen autonomi och helt odefinierat körområde behandlades. / This report is the result of a bachelor thesis completed at KTH (Royal Institute of Technology, Stockholm, Sweden) during spring 2018 in machine design. The project was executed in collaboration with KTH and Skogforsk (the Forestry Research Institute of Sweden), which is the central research body for the Swedish forestry sector, and financed jointly by the government and the members of the institute. The background of the project is the ever increasing requirements of ecology and ergonomics in the business, and the shortage of operators. The object of the project was to prepare and adapt a forwarder developed by Skogforsk (among others), Xt28, for automation. A forwarder is a forestry vehicle used for transporting logs. As the process of fully automating a vehicle is very extensive this project was limited to focusing on the forwarder's perception of the surrounding environment. The reader will take part in the development of a protective sensor unit, fitted for the demanding environment of a forwarder in Sweden. Requirements for vehicle automation, suitable sensors and placement, possible load cases, and attachment possibilities will be considered. A challenge during the project was the lack of earlier work and projects found on the same area, where self driven vehicles and operation o road were both regarded.