The purpose of this master thesis is to construct a steering transmission, for a trackedvehicle, containing two hydraulic circuits which are connected. The steeringtransmission should be mechanical to avoid steer-by-wire.BAE Systems Hägglunds has in an earlier study examined a system with two hydraulicpumps and one hydraulic motor, but the safety of the system wasn?t sufficient.To achieve sufficient redundancy there must be two hydraulic motors, which arecontrolled separately. When the two systems are connected in one point, this point is acritical part of the system because it directly affects both circuits. If one of the hydrauliccircuits fails the other should be able to operate independently as a steeringtransmission.

This report relate a concept study that consider a number of different proposals to improve the overcharging system in BAE Systems Ha?gglunds Tracked vehicle series BvS10, to maintain sealevel power at extreme altitude.At high altitude the power losses beacuase of the air density that decreases, which results in less fuel can be burned. The decreasing of air density also gives rise to fatigue failure of the turbocharger unless power is reduced.The proposals shall be as required by BAE Systems Ha?gglunds economically sustainable and defensible from a packing perspective. That means the selected solution must have a reasonable price tag and at the same time a minimal impact on adjacent components.The basis for this thesis is based on benchmarking of both the auto industry as the flight industry, to find inspiration and tips for improvement.Some of the concepts have after gathering facts and calculations been excluded while other solutions has been considered as workable and thus interesting for BAE Systems Ha?gglunds.Initially the current turbochargingsystem was analyzed in order to determine the starting point and thus be able to fix the current problems surrounding high altitude driving.

In the automatic manual transmission system, Opticruise, the choice of gear is based on several parameters such as road incline, driving resistance and vehicle mass. Many different mass estimations are made during driving. A final vehicle mass is then used to determine the current gear. Construction vehicles are often not equipped with air suspension and can therefore not estimate the vehicle mass when standing still. If that sort of vehicle is reloaded while standing still an incorrect mass estimation will be used and as an effect of that also a wrong gear.

This is a thesis presents a differential gear which is found in a Tracked vehicle called BvS10. The Tracked vehicle is manufactured by BAE Systems Hägglunds AB in Örnsköldsvik, Sweden. The differential gear has a bolted house. The differential meets the requirement specifications, but the problem is that the bolts are sheared off because of the extreme torque that the differential is exposed to resist.Previous report on the differential show pictures of bolts which have been sheared off at the threads. This report is also includes three lists that explain seven different proposals which some are approved and some are not, and the report also presents the force, tensile, and shear stress.In a bolted connection there is both axial tension stress and radial shear stress, which can lead to wear out and broken bolts.

The demand for biogas as vehicle fuel has risen sharply and there is a great need for increased production. A possible addition of vehicle gas can be produced by upgrading landfill gas which is formed by degradation of organic waste. This thesis investigates the potential of producing vehicle fuel from landfill gas in the region of Biogas Öst.In 2008, an amount of 32 million Nm3 landfill gas was extracted in the region. This level can be maintained for another ten years if the efficiency of gas extraction is improved. The annual production will decrease with time since landfills aren?t allowed to receive more organic waste.

Saab Aerosystems has a long tradition and a lot of competence in the field of flight simulation. Their ambition to broaden the market horizon has led to a discussion about also selling vehicle simulation solutions, both for military and civilian use.The aim of this thesis is to investigate the driver?s experiences of the accelerations he or she is exposed to whilst driving in rough terrain. The results may be used as a basis for future decisions and can act as a platform for the construction of an effective simulation model.To investigate the driver?s exposure of acceleration, some kind of dynamic simulation is needed.

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.

AbstractThe dependency of fossil fuels in the transport sector causes large emissions of carbondioxide. This problem can we reduce by using vehicle gas from digested solid manure and leftover of pasture. I have studied the potential for this in the county of Västernorrland. Thepurpose is to investigate how much vehicle gas that can be extracted.One central, large scale digestion and upgrade plant should be placed in Härnösand. Theamount of pasture and manure that is economical and practical available is enough to produce2,7-3,5 millions Nm3 vehicle gas.

This report covers the conceptual design of a new one person hybrid vehicle that is to be fast and convenient to drive on the roads. The vehicle is most of all supposed to be used as a commute vehicle but can also be used at other occasions as well.During the work with this project the group has focused on three larger areas, the outer design (body), wheel chassis and an ergonomically designed interior. The group was not able to just create these parts in 3D to get a trustworthy vehicle, hence number of other components and details were also created to get a better entirety.The outer design starts with idea generation and sketches and ends with a 3D model which is rendered to show how the final product is going to look. The design of the body has been going on during the entire work process due to new ideas and improvements that seemed interesting and had to be changed.The wheel chassis also started with idea generation, research and sketches. It ended up with a simulated 3D model which later on was mounted on the vehicle body to show how the vehicle is going to perform during usage.

  Befintliga studier har påvisat att genetiska algoritmer presterar bättre om de ges en bra startpopulation. I denna rapport presenteras en lokal sökalgoritm för att skapa en population med fokus på ?vehicle routing?-problem. Algoritmen använder sig av heuristik i en blandning av simulated annealing och tabu search för att skapa individerna till populationen. Utvärderingar av algoritmen på ett praktiskt problem visar att den ger en bra start jämfört med en slumpmässig startpopulation, vilket är vanligt att använda.

BAE Systems Hägglunds has a long history of producing high performance terrain Tracked vehicles (mostly for military applications), and they are now aiming at developing a tracked forwarder with similar techniques.The forwarder will be of series hybrid type where a diesel engine via a generator will power the motors (one for each drive wheel). Thanks to individually controlled motors and the gentle rubber tracks, this forwarder is calculated to have a considerably higher average speed in the terrain and to be more gentle to the soil. The forwarder with a weight of 11 metric tons and a load capacity of 15 metric tons is specified to have an average working speed of 7-10 km/h, a top speed in terrain of 15 km/h and a top speed on roads of 40 km/h.This master?s thesis aims at developing a conceptual design of the forwarder?s drive module which includes electric motor, gear unit, brake and drive wheel.To investigate if the requirements can be fulfilled a study of the dimensioning loading scenarios has been carried out. The resulting needs regarding the torque has been considered in order to determine the required gear ratios for different motor options.

This master thesis is a study on how a rategyro triad, an accelerometer triad, and a magnetometer triad can be integrated into a navigation system, estimating a vehicle?s attitude, i.e. its roll, tipp, and heading angles. When only a rategyro triad is used to estimate a vehicle?s attitude, a drift in the attitude occurs due to sensor errors.

The purpose of this master thesis is to evaluate how internal vehicle information inScania buses and trucks can be used for evaluation of driver performance regardingfuel economy, vehicle wear, traffic safety, emissions and cargo damage. To someextent it was examined whether this information could be used for training the driverto a better driving style. In addition, a prototype for such a system was developed.By first defining what distinguishes a talented driver and how he/she differs from apoor driver, followed by a study of the internal vehicle communication, a system thatin real-time gathers and interprets vehicle data could be developed.The resulting system can with reasonably high reliability detect a number of trafficevents (such as braking, lane changing or hilltops). At each such event, the driver?sbehaviour can be evaluated.

The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years.

The low bearing capacity of roads during the spring thaw and periods in the autumn leads every year to increases costs for Holmen Skog. To reduce costs and increase accessibility Holmen Skog decided to install and test a CTI-system. Central tire inflation (CTI) is a system that makes it possible to monitor and vary a vehicle?s tire inflation pressures from the cabin, while the vehicle is in motion. When tire pressures are reduced, the area of the contact surface between the tire and the road increases, thus reducing the ground pressure. The purpose of this study was to evaluate the CTI-equipped vehicle and analyze if the CTI technology is economical defensible during the thaw 2005.