The evolution of electronics in the vehicle industry has introduced the possibility for more X-by-wire systems in future vehicles. However, the use of steer-by-wire systems has not yet been widelyimplemented. This opens up an opportunity to explore strategies around the potential use of such asystem.The purpose of the project was to evaluate how to design a variable steering ratio which would give asuitable ratio in all speeds. This would, in turn, make it possible to reduce the need for large steeringwheel angles. Additionally, steering wheel designs which can be implemented with a steer-by-wiresystems are discussed and what possibilities there are to move certain interfaces to the steering wheel.The evaluation process consisted of driving a real car with a constant steering ratio in normal trafficand later modelling a variable steering ratio and testing it in a simulator. This was to get data on howlarge steering wheel angles that are needed in different driving scenarios to then be able to design asuitable variable steering ratio. The tests conducted on normal roads in a real car has shown that thedriver utilises the whole steering range (full lock-lock distance) at speeds below 30 km/h and about±10° on the steering wheel at high speeds. The tests conducted in the simulator show that the variablesteering ratio presented in this report decreases the workload on the driver most of all at speeds below30 km/h.The variable steering ratio presented has been compared with a fixed steering ratio in the simulatorand the tests show that the variable steering ratio works similar to the fixed steering ratio in the samescenarios. The variable steering ratio also decreases the need for a steering wheel angle greater than±180°.

Yes / An analysis is presented to determine the best selection criteria for the properties of a steering shaft to be used as a back-up apparatus for a steer-by-wire (SBW) system during system failure. The properties of interest are the steering-shaft stiffness and its damping coefficient. A mathematical model representing the failed state of an SBW system is derived, and a set of experiments to validate the model is presented. Once the model had been validated, further predictions of the car¿s handling behaviour for a range of steering-shaft properties and different road speeds were completed by simulations in MATLAB/Simulink. A minimum stiffness which did not cause the car to become unstable owing to overshoot was determined, and the minimum acceptable damping coefficient value was derived. It is concluded that the suggested stiffness and damping coefficient values increased the steering ratio, and the results of further investigations are presented, which confirm that the vehicle is safe to be driven in the event of SBW system failure if the recommended shaft properties are used.

Yes / The fundamentals and preliminary analyses of an innovative future technology referred to as `semi-active steering' (SAS) are presented in this article. The proposed steering system configuration is similar to a conventional electrical power-assisted steering with the replacement of the rigid steering shaft with a low stiffness resilient shaft (LSRS), the presence of which allows `active control¿ to be performed on vehicles similar to the concept of full steer-by-wire (SBW). But, unlike SBW, the LSRS is an integral part of the system characteristics. The advantages of the semi-active system in comparison with SBWand other conventional systems are demonstrated. A mathematical model to predict the mechanical properties of the LSRS has been developed, and experiments were conducted on a medium-sized car fitted with an LSRS to verify that vehicle stability and drivability can be ensured in the event of active system failure. The results have indicated that the vehicle was stable and safe to be driven at low speeds, and is predicted to be driveable and safe at higher speeds. It is concluded that an SAS system of this type has the potential to improve the safety of SBW systems.

<p>The purpose of this master thesis project has been to analyze and document the Sirius 2001 Concept Car. In addition, it has also been a goal to get the car in a usable state by implementing new software on the on board computers. </p><p>The car is a Tiger Cat E1 that is modified with four wheel steering and an advanced X-by-Wire system. The computers in the X-by-Wire system consist of six TTP PowerNodes that communicate with each other over a redundant, fault tolerant TTP/C communications bus. The computers are connected to a number of sensors and actuators to be able to control the car. </p><p>This project has contributed to the car in several ways. A complete documentation of the systems implemented in the car is one. Another is a programmers manual which significantly lowers the threshold when working with the car. Last but not least is the modifications in hardware and software, which have made the car usable and show some of the possibilities with the system. </p><p>The results show that the Sirius 2001 Concept Car is a suitable platform for research in car dynamics and fault tolerant systems. The work has also shown that the TTP/C communication model works well in an application like this.</p>

The purpose of this master thesis project has been to analyze and document the Sirius 2001 Concept Car. In addition, it has also been a goal to get the car in a usable state by implementing new software on the on board computers. The car is a Tiger Cat E1 that is modified with four wheel steering and an advanced X-by-Wire system. The computers in the X-by-Wire system consist of six TTP PowerNodes that communicate with each other over a redundant, fault tolerant TTP/C communications bus. The computers are connected to a number of sensors and actuators to be able to control the car. This project has contributed to the car in several ways. A complete documentation of the systems implemented in the car is one. Another is a programmers manual which significantly lowers the threshold when working with the car. Last but not least is the modifications in hardware and software, which have made the car usable and show some of the possibilities with the system. The results show that the Sirius 2001 Concept Car is a suitable platform for research in car dynamics and fault tolerant systems. The work has also shown that the TTP/C communication model works well in an application like this.

The thesis deals with the calculation and evaluation of the flight characteristics of the aeroplane Z 143 with the power unit Lycoming AEIO-580-B1A. The first part of the text focuses on a general description of the aircraft, its geometric characteristics and calculation of mass and aerodynamic characteristics. In terms of flight performance there are compared the values for contemporary model and developmental aircraft with a more powerful engine. Another part of the work deals with the calculation of properties in terms of stability and manageability. In this section regards the determination of the results of the flight characteristics and their assessment of whether they comply. In the end I discuss the individual results and comment the possible recommendations on correction or improvement of these properties.

The object of this diploma thesis is revision of coolant system skid steer loaders “BOBEK” B861, B961 and his eventually optimization for prevention of overheating hydraulic system and engine. The first part dedicate of general issues of coolant skid steer loaders. The second part is the calculation during heat stress hydraulic systems of loader and the third part include proposals for solutions problems of overheating hydraulic systems and combustion engine.

The diploma thesis deals with computational analysis of driving behavior of a vehicle. The first section summarizes and explains the basic parameters of steering geometry. Next section covers the tests which are used to study driving behavior of vehicles. The practical part consists of computational model that is able to simulate and evaluate tests of step steer input.

Simulation tools have progressed largely and in modern times they are commonly usedby engineers to design and simulate machines or part of machines before building and deploying them in the field. The field of Hardware-in-the-loop (HIL) is gaining significant interest among companies as they strive to enhance product safety and reliability simul-taneously reducing testing costs and accelerated development speed. This study presents the Real Time simulation improvements effectuated to the Steer and Brake by wire system on an underground face drill rig. These improvements in the model are validated with a comparison between simulated environment and real test data from the machine using a cosimulation between Matlab&amp;Simulink with AMESim. At the end, this improved model is prepared to be compatible with an Hardware-in-the-loop application that requires an adequate computational time.

With aging, the sensory, motor, and central nervous system deficiencies lead to inadequate bicycle postural control in older cyclists. Similarly, variety in riding skills leads to different bicycle postural control strategies. Cycling seems to be an automated task but keeping the bicycle stable at low speed, pedaling, and steering requires continuous physical and cognitive effort, and in long term may lead to fatigue induced by steering and stabilizing the e-bike at low forward speeds especially in older cyclists. E-bikes enables riders to cycle for langer duration and distance by reducing the physical fatigue. There is an increasing societal interest in electric bicycles where in 2021, 26. 73 billion US dollars worldwide have been invested on e-bikes and by 2027 this global market size will increase to 53.53 billion US dollars (Statista). However, with increased numbers of e-bikes, bicycle accidents due to inadequate steering and balance control by older cyclists have increased, which suggests needs for extra safety measures to maintain balance on a bicycle for challenging situation such as facing undesired disturbances or low forward speeds. We developed a prototype steering assist which aims to increase safety and improve the user experience, by reducing the steering effort and enhancing the bicycle postural control (rider-bike balance control). We investigated the potential effectiveness ofthe steering assist technology in real life challenging situations. Our present study should be considered exploratory research to find the potential effectiveness of the steering assist technology in improving the user experience and safety compared to a non-assistive e-bike. The improved bicycle postural control is validated by smaller range, variability, and rate of steering and roll trajectories when the rider is subjected to an unwanted disturbance. Improved bicycle postural control is expected based on the reduced need for compensatory behavior in the presence of assistive technology. Decreased steering effort is expected due to reduced demand for acute steering control in the anticipatory control strategy.