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This report contains the first step towards a complete, fully autonomous, robust bucket fill regulator for a wheel loader working with gravel materials. The bucket fill procedure is the most critical part of the work cycle of a wheel loader. It is a task that has a long learning curve and also is weary, even for experienced drivers. The automation of it could therefore have a big impact on the cost effectiveness for wheel loaders and for the comfort of the drivers. In this report, a suggestion for the complete solution of an automatic bucket fill regulator is presented. A regulator prototype is also constructed with a Volvo L120F as the base. The scope for the prototype is limited to one type of gravel material and quite optimal conditions for the wheel loader, but the complete solution is kept in mind throughout the synthesis. The constructed regulator is prepared for expansion, but the implementation and field testing is limited to the scope.

The aim of the thesis is to derive a mathematical model of the engine and driveline in a passenger car, capable of describing the wheel speed disturbances related to the engine and driveline. The thesis is conducted in order to improve the disturbance cancelation algorithm in the indirect tire pressure monitoring system, TPI developed by NIRA Dynamics AB. The model consists of two parts, the model of the engine and the model of the driveline. The engine model uses an analytical cylinder pressure model capable of describing petrol and diesel engines. The model is a function of the crank angle, manifold pressure, manifold temperature and spark timing. The output is the pressure in the cylinder. This pressure is then used to calculate the torque generated on the crankshaft when the pressure acts on the piston. This torque is then applied in the driveline model. Both a two wheel and a four wheel driveline model are presented and they consist of a series of masses and dampers connected to each other with stiff springs. The result is a 14 and 19 degrees of freedom system of differential equations respectively. The model is then validated using measurements collected at LiU during two experiments. Measurements where conducted of the cylinder pressure of a four cylinder petrol engine and on the wheel speed of two different cars when driven in a test rig. The validation against this data is satisfactory and the simulations and measurements show good correlation. The model is then finally used to examine wheels speed disturbance phenomenon discovered in the huge database of test drives available at NIRA Dynamics AB. The effects of the drivelines natural frequencies are investigated and so is the difference between the disturbances on the wheel speed for a petrol and diesel engine. The main reasons for the different disturbance levels on the front and rear wheels in a four wheel drive are also discussed.

In this essay a conclusion about the way female characters are portrayed in fantasy novels will be attempted through an analysis of one selected female character from each selected novel. The works that have been chosen are; J.R.R. Tolkien’s The Lord of the Rings, Robert Jordan’s The Eye of the World and A Game of Thrones by George R.R. Martin. The analysis will be done with the help of examples and theories from both feministic criticism and gender studies. During the course of the discussion the background of the fantasy genre and goal of the scientific theories will be explained.The fantasy genre in itself allows its authors a chance to criticize the norms of our society, freed from the restraints of realism. The findings of this essay however, imply that some fantasy authors forsake this chance in order to more accurately emulate the medieval European society or in fact actively reinforce patriarchal norms.

Wheelchair is for those who cannot walk independently and need assistances in moving around. Six-wheel Power Wheelchair has great functions, such as large sphere of actions, no movement injuries, great stability, and small radius of gyration. The purpose of this paper is to apply the idea of engineering design method and offer a design theory for chassis mechanism for Six-Wheel Power Wheelchair. Firstly, the evolution of chassis mechanism for wheelchair is discussed and the existing chassis mechanism for wheelchair is analyzed. Based on the knowledge, this paper concludes the fundamental functions and structural characteristics of chassis mechanism for power wheelchair and lists the design requirements. Secondly, applying the creative mechanism design procedures, a new design for chassis mechanism and the Kinematic design for six-wheel power wheelchair are proposed and computerized Finally, using CAE software stimulating the designs, the paper presents the three-dimension graph and prototype of the designs.

<p>Idag är det möjligt att modellera de hydrauliska och mekaniska systemen hos en hjullastare. Det går även i viss omfattning att simulera omgivningen samt de förarkommandon som krävs för utförandet av en önskad uppgift. Däremot är det enda sättet att få reda på hur en förare kommer att uppleva maskinen, dess körbarhet, att bygga en fungerande prototyp och be en förare att testa den.</p><p>Syftet med det här examensarbetet var att hitta en korrelation mellan förarens bedömningar och mätdata insamlade från en hjullastare under körning. Resultaten är sedan tänkta att användas i framtida simuleringar. Olika hjullastare testades av en grupp provförare och deras subjektiva bedömningar såväl som mätdata från hjullastarna samlades in.</p><p>Slutsatsen är att det går till en viss del att förutsäga körbarheten från insamlade data om förarens körstil är känd. Då förarnas körstil skiljer väldigt mycket är det är inte möjligt att dra allmänna slutsatser om körbarheten.</p> / <p>Today it is possible to model all hydraulic and mechanical systems of a wheel loader. To an extent the surrounding environment and the operator input required for a desired operation can also be simulated. However the only way to determine how an operator will perceive the handling qualities, the operability, of the wheel loader is to assemble a working prototype and ask an operator to try it out.</p><p>The purpose of this Master thesis was to find some correlation between the drivers’ opinions and data recorded from the machines during operation. The results are intended to be used in future simulations. Different machines were tested by a group of drivers and their subjective impressions, as well as measurements from the machines were collected.</p><p>The findings from the analysis are that the operability can be determined to a certain extent if the driver’s behaviour is known. Because of the differences in the way the drivers operate the machine it has not been possible to draw any general conclusions.</p>

The Reaction Wheel Pendulum (RWP) is an interesting nonlinear system. A prototypical control problem for the RWP is to stabilize it around the upright position starting from the bottom, which is generally divided into at least 2 phases: (1) Swing-up phase: where the pendulum is swung up and moves toward the upright position. (2) Stabilization phase: here, the pendulum is controlled to be balanced around the upright position. Previous studies mainly focused on an energy method in swing-up phase and a linearization method in stabilization phase. However, several limitations exist. The energy method in swing-up mode usually takes a long time to approach the upright position. Moreover, its trajectory is not controlled which prevents further extensions. The linearization method in the stabilization phase, can only work for a very small range of angles around the equilibrium point, limiting its applicability. In this thesis, we took the 2nd order state space model and solved it for a constant torque input generating the family of phase-plane trajectories (see Appendix A). Therefore, we are able to plan the motion of the reaction wheel pendulum in the phase plane and a sliding mode controller may be implemented around these trajectories. The control strategy presented here is divided into three phases. (1) In the swing up phase a switching torque controller is designed to oscillate the pendulum until the system’s energy is enough to drive the system to the upright position. Our approach is more generic than previous approaches; (2) In the catching phase a sliding surface is designed in the phase plane based on the zero torque trajectories, and a 2nd order sliding mode controller is implemented to drive the pendulum moving along the sliding surface, which improves the robustness compared to the previous method in which the controller switches to stabilization mode when it reaches a pre-defined region. (3) In the stabilization phase a 2nd order sliding mode integral controller is used to solve the balancing problem, which has the potential to stabilize the pendulum in a larger angular region when compared to the previous linearization methods. At last we combine the 3 phases together in a combined strategy. Both simulation results and experimental results are shown. The control unit is National Instruments CompactRIO 9014 with NI 9505 module for module driving and NI 9411 module for encoding. The Reaction Wheel Pendulum is built by Quanser Consulting Inc. and placed in UT’s Advanced Mechatronics Lab. / text

This thesis presents the results of a qualitative research study that examined the resilience development with six Anishinabe (Ojibway) women. This study examined from the women’s perspectives, “What meaning(s) do First Nation graduates of secondary or post-secondary education make about risk and/or protective factors that may have affected their success in completing their degree/diploma requirements?” In this research, I closely examined the historical accounts and progressive educational changes of six successful Anishinabe women who attended either the residential, provincial or band operated schools. The narrative/storywork voiced by the women was gathered by one in-depth interview and were analyzed in two parts. First, the Western idea of resilience (Benard, 2004) was examined. Second, the development of resilience utilizing Indigenous narrative/storywork (Archibald, 2008; Thomas, 2008; Wilson, 2008) and the cultural framework of the Medicine Wheel teachings (Bopp, Bopp, Brown, & Lane, 1988; Medicine Wheel Evaluation Framework, 2012) was explored. The findings from this thesis revealed that through protective factors and/or supports of their community, environment, school, and family and restored Indigenous philosophy, maintained culture, language, spirituality and traditional worldviews, a process of resilience emerged and/or was developed and overpowered risk factors, challenges and/or adversities. The amalgamation of findings supports what research suggests that Aboriginal people exist in two worlds, their world and mainstream world (Fitznor, 2005). Co-existance, acceptance, and a balance of both worlds are supports and fundamental keys to resiliency and educational success.

This thesis evaluates an electric vehicle with four independently-controlled in-wheel electric motors. The electric vehicle investigated in this work requires a main con- troller that not only coordinates with each individual motor drive controller, but is also needed to distribute torque and power to each in-wheel motor. The controller adjusts the speed of each motor to the driving conditions according to the require- ments and emulates the behavior of a mechanical di erential. Then, in addition to the electronic di erential controller, a simple yet robust control strategy for maximiz- ing traction force between tire and road is developed and presented. Moreover, the controller continuously senses the yaw rate and prevents over- and under-steering by adjusting the torque on the right or left wheels. Simulation and experimental results validate the proposed strategy.

7th IFAC Symposium on Advances in Automotive Control, The International Federation of Automatic Control, September 4-7, 2013. Tokyo, Japan