During life of railway vehicles, shape irregularities develop on wheels and rails because of wear. The shape irregularities then affect forces in wheel-rail contact and cause further damage of contact surfaces, vibrations and noise and increase risk of derailment. A numerical simulation of railway vehicle motion with more details on contact surfaces geometry was created to investigate dynamic contact loads in wheel-rail contact. A variety of methods can be used to evaluate forces in rolling contact, the method chosen for this study was algorithm CONTACT based on boundary element method. Four studies are presented in this papers: contact loads from a wheel with a flat and with a wavy tread pattern, loads on wavy rail and load in a curve. The first three studies investigated effects of existing wear patterns, the last one looked for cause of common wear pattern developing on rails. Results of the studies with worn components used showed that the worst kind of shape irregularities is a flat present on wheel. This type of shape cause loss of contact and following impacts. The study of ride in curve showed that cause of high wear in curves, especially those with small radii, is caused by vibration of wheelset. This vibration is then caused by different length of inner and outer rail and wheels travelling along a different path.

This paper focuses on the kinematic and dynamic numerical simulation of mechanisms by applying a numerical method, and a complex simulation programme built on it, developed by the author. Described are mathematical principles of the numerical method used and also the programming progression of the important parts of the application and its optimization. The final part includes comparative measuring of the accuracy and performance.

Title: Case study of walk and run kinematics involution Objectives: Identify differences in the execution of walk and run, their time and space parameters, by two couples in close family relationship (father and son; father and daughter), who participate in the performance sport of running. Methods: Two family couples (3 men and one woman) participated to laboratory and field tests. Each subject participated in two kind of walk (walk on treadmill at the speed of 5km/h and walk on the athletic track - at natural walking speed) and according the abilities to 15 speeds of running locomotion (13 speeds on treadmill and 2 speeds on the athletic track). Kinematics of all speeds was analysed with the software Kinovea 0.8.15. The thesis is a pilot study, that is trying to ascertain the extend of difference of the execution of locomotion of subjects in the male parental line (father and son; father and daughter). Results: Noticeable difference in the characteristics of all measured speeds of locomotion are seen by the older two members of relatives (74,8 and 40,2 years), the faster was the evaluated speed, the larger was the difference in stride length (6 to 25 cm) and in stride frequency in walking as well as in running (23 to 38 steps per minute). For the second tested two members of a family (53,7 and...

Previous studies proposed that Neandertals had one third higher energetic cost of locomotion than anatomically modern humans. Greater cost of locomotion could disadvantage Neandertals in competition with anatomically modern humans and could be a factor in their extinction. Greater cost of Neandertal locomotion was ascribed to their shorter lower limb and greater body mass. However, Neandertals differed also in other morphological parameters that were not considered in estimation of their locomotor cost. In this dissertation we model locomotor cost of Neandertals and anatomically modern humans using previously described relation between muscle force production and energetic cost of movement. We estimate the key locomotor parameters using a model developed by us from osteometric data from literature (n =50) and from our measurement (n = 21), and from kinematic data of 26 individuals. Further, we analyze the effect of relative lower limb length (in relation to body mass) and crural index on energetic cost of locomotion. Our results suggest that walking of Neandertal males was 9-14% energetically more demanding than walking of anatomically modern males. Nevertheless, the walking cost of Neandertal females was similar to that of anatomically modern females. Inclusion of lower limb proportions into the...

This diploma thesis deal with conceptual design of racing car of T1 category. Car consist of tubular frame, front and rear double wishbone suspension, braking system and conceptual design of the fairing. These are the basic of this thesis. For the completeness of the design, the location of the crew and the placement of the components inside the frame are also proposed. Adams Car 2016, Autodesk Inventor 2016, Ansys Workbench 18.1 were used for designing, testing, simulation and calculations. Designed T1 category race car meets International Automobile Federation (FIA) technical standards and safety regulatons.

Conformal geometric algebra is defined in the thesis. Representations of geometric objects and possibilities of their geometric transformations are presented. Conformal geometric algebra is applied to the calculation of forward kinematics of a robotic manipulator UR10 from Universal Robots. It is also applied to determine the position of the machine based on the location and rotation of two cameras. Then it is used in an inverse task, where based on records from the two cameras, dimensions of the UR10 manipulator and possibilities of its movement, the mutual position of these cameras is determined. And consequently the possibilities of their location in space. Finally, the derived procedures are implemented in a custom program created in the CluCalc environment, using which a sample example verifying the correctness of these procedures is calculated.

This diploma thesis deals with a design and implementation of an embedded device (module), used to control a robotic manipulator. The module instructs servomotors of the manipulator to move according to the commands received via USB interface. The module consists of two double-sided printed circuit boards. The first one allows connection to the CAN bus, redundant and thus reliable power supply for servomotors as well as the whole module. The second board, compute oriented one, embeds powerful microcontroller used to communicate with the servomotors and to solve the kinematics tasks. As a part of the thesis a graphical user interface as well as a web-oriented interface were developed. Both interfaces allow full control of the manipulator. All the communicating buses, tools and methods used during the design and implementation phases of the work are described in the thesis. Finally, measurements proved improvement of the motion smoothness and response times in several orders of magnitude in comparison to the previous system.

Tato diplomová práce se zabývá revizí elektroniky robotického vozidla car4 se zaměřením na měření rychlosti otáčení kol, výkonovou a řídicí elektroniku. Car4 posloužilo jako základ pro již přes 20 diplomových prací od roku 2010. To znamenalo, že některé základní aspekty car4 byly zastaralé. Bylo vytvořeno schéma elektroniky vozidla, které bylo dále využito pro vývoj a výrobu nového hardwaru. Komponenty byly poté otestovány a implementovány na vozidlo. Dále byl vytvořen kinematický model 4WS vozidla za použití Ackermanovy geometrie, který byl implenetován a otestován na car4. Dále by měl sloužit jako základ řídicího algoritmu pro budoucí vývoj car4.

The diploma paper deal with control problems of a four legged walking robot. They endeavour to establish and partly implement the walking and control algorithms. They are divided into six parts. Individual chassis types and their advantages and drawbacks are analysed in introduction. Next part describes mechanical design of the robot and also all realised electronics facilities. The third part describes in detail sensors that are used by the robot. Following part deals with description of robot's walking. It explains individual walking phases and analyses both static and dynamic stability. Next part contains description of the robot's software facility. The software facility of the control micro-controller and the algorithm that generates walking are explained in this part. It also describes software facility of control application in computer. Exploration of the possibilities for wireless control is carried out in the last part.

The main object of this thesis is the proposal of fitting (setting) hydraulic cylinder into test equipment of ball-joints of company TRW-DAS Dačice a.s. The thesis includes a short review about testing ball-joint of above company and about liquid mechanisms. Also, there are analyzed demands for fitting (setting) hydraulic cylinder into testing equipment. In the main part of this thesis there is described my own constructive proposal with numeric calculations in proper software. In enclosure there are all analytical calculations with productive drawings and an assembly drawing.