A three-link, single-degree-of-freedom mechanism, named the Spirograph linkage, is investigated in this thesis. What is special about this open-chain mechanism is that, by the use of a chain and two sprockets and therefore maintaining a constant angular velocity ratio between the two rotating links, the path traced by this mechanism can be shown to be either an epitrochoid or a hypotrochoid. Through the understanding of the formulations of the trochoids, the relations between the design parameters of the Spirograph linkage and the corresponding path patterns are derived. With certain design parameter combinations, the Spirograph linkage is able to feature paths with cusps, which means dwells and are useful in applications. A design chart for such cusp-generating Spirograph linkages is then included in the thesis for the sake of convenience. In addition, by matching the link-length ratio with the angular velocity ratio, ways for finding closed single-loop paths of the Spirograph linkage are also studied. As for the path generation problems concerning only a fraction of the entire path, we compare results given by the classical precision point scheme with assorted combinations of initial conditions. In the latter part of the thesis, non-circular sprockets are also introduced to provide the Spirograph linkage additional freedom to cope with the demand of more flexible, i.e., non-symmetrical shapes of the path. However, many constraints are to be imposed on the design process of such linkages, and these design limitations are elaborated in the thesis. At last, the use of Newton¡¦s method, the selection of the proper type of trochoids, the application of the envelop method for obtaining the profile of the non-circular sprocket, the analyses of angular velocity ratios, etc. are all exemplified in the several numerical examples of the thesis.

The aim of the diploma thesis "History of selected math problems" is to explore specific math issues, which famous mathematicians dealt with in the past, using up-to-date knowledge and methods. For each issue there is explained history and diagrams describing its origin and solution.

After a huge amount of success within the military, the benefits of the use of unmanned aerial systems over manned aircraft is obvious. They are becoming cheaper and their functions advancing to such a point that there is now a large drive for their use by civilian operators. However there are a number of significant challenges that are slowing their inevitable integration into the national airspace systems of countries. A large array of emergency situations will need to be dealt with autonomously by contingency management systems to prevent potentially deadly incidences. One such emergency situation that will need autonomous intervention, is the total loss of thrust from engine failure. The complex multi faceted task of landing the stricken aircraft at a potentially unprepared site is called a forced landing. This thesis presents methods to address a number of critical parts of a forced landing system for use by an unmanned aerial system. In order for an emergency landing site to be considered, it needs to be within glide range. In order to find a landing site s reachability from the point of engine failure the aircraft s glide performance and a glide path must be known. A method by which to calculate the glide performance, both from aircraft parameters or experiments is shown. These are based on a number of steady state assumptions to make them generic and quick to compute. Despite the assumptions, these are shown to have reasonable accuracy. A minimum height loss path to the landing site is defined, which takes account of a steady uniform wind. While this path is not the path to be flown it enables a measure of how reachable a landing site is, as any extra height the aircraft has once it gets to the site makes a site more reachable. It is shown that this method is fast enough to be run online and is generic enough for use on a range of aircraft. Based on identified factors that make a landing site more suitable, a multi criteria decision making Bayesian network is developed to decide upon which site a unmanned aircraft should land in. It can handle uncertainty and non-complete information while guaranteeing a fast reasonable decision, which is critical in this time sensitive situation. A high fidelity simulation environment and flight test platform are developed in order to test the performance of the developed algorithms. The test environments developed enable rapid prototyping of algorithms not just within the scope of this thesis, but on a range of vehicle types. In simulation the minimum height loss paths show good accuracy, for two completely different types of aircraft. The decision making algorithms show that they are capable of being ran online in a flight test. They make a reasonable decision and are capable of quickly reacting to changing conditions, enabling redirection to a more suitable landing site.

The main aim of master’s thesis was to handle the computing proposal and the construction design of the powertrain of racing Wankel rotary engine with 300 kW power output and in the case of 9000 speed per minute. On the basic of these values was made the primary design of the rotary engine, design of the eccentric shaft and rotor housing. Mechanical stress and torsional vibrations of the eccentric shaft were analyzed by using the course of indicator diagram.

This master's thesis deals with the design of FEM model of gear pair with an intention to find out how stiffness changes during meshing. It firstly describes the necessary knowledge needed to analyse the problem, like the geometry of an involute tooth and evaluation of meshing stiffness. Followed by a description of work procedures from the creation of models through settings of mesh, contacts and analysis to evaluating of results.