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The thesis is devoted to the analysis of road resistances of a car. The first part deals with the theory of individual road resistance which counteracts the movement of the car. The chapters are given the formula for calculating individual road resistance and in the end is mentioned relationship of total road resistance. The second part is focused on the construction of tires, their signs and detailed description dimensions. This section also describes a tire according to the shapes of designs, their type and how to properly store them. The next part explains the theory of rolling the vehicle wheel according to the type of pads. The penultimate section describes the methodology for measuring the road resistance in real traffic. The conclusion describes experimental measurements of passive losses car at various inflation pressures made on vehicle testing institute of technology and automobile traffic. In this passage it is also a graphical and verbal evaluation of practical measurement.

This thesis is focused on measuring the shape of loaded tire and finding dependencies between inner tire pressure, load and the influence of these parameters on the resulting shape of the tire. Data for these dependencies were obtained by using a constructed measuring stand and 3D optical technology. Found dependencies describe the change in shape of the tire in specific mathematical functions, and served the creation of a parametric model of the tire. The main finding of this thesis is that the tire is actually behaves according to dependencies described by varying degrees of polynomial function.

The main aim of this diploma thesis is to deal with the influence of tire properties and parameters of driving dynamics. In the introduction are discussed the driving dynamics of vehicles and the importance of tires and their construction. The second part is devoted to implementation and evaluation of the own experiment. My experiment is to test the braking tire inflation and condition of various different sizes. The conclusion summarizes the importance of proper tire condition.

The non-linear model of pneumatic acting system, consisting of proportional directional control valve and symmetric rodless pneumatic cylinder is developed and investigated in this paper. This model enables to evaluate influence of essential nonlinearities concerned with working characteristics of airflow regulating valves and pneumatic cylinders on dynamics of the system. The modeling results of pneumatic acting system under several initial working conditions are presented and discussed in this article. The model reference based adaptive control method of force regulation in electro-pneumatic servo system is proposed and investigated in this paper to. This method allows eliminating of influence of nonlinearities of pneumatic cylinder and directional control valve on behavior of force regulation system. Therefore controllers of higher hierarchy level such as velocity and position controllers can be designed using conventional methods based on quantitative optimum. The modeling results of investigated system are presented in the paper.

As farm tractors and field equipment become larger and heavier, there is a growing concern about soil compaction. Heavy equipment and tillage implements can cause damage to the soil structure. The soil structure is important, because it determines the ability of a soil to hold and conduct water, nutrients, and air. These properties are necessary for plant root activity. The basic connection between soil and machine are tyres. The choice of tyres in agriculture not only affects economy of soil operations and traffic, but it affects the soil structure too. The manufacturers of tyres and agricultural machines are developing new constructions, which has goal to decrease impact of heavy machinery on soil structure. Practical part of diploma thesis deals with the influence of load and inflation of tractor tyres on soil compaction. The results of experimental measurement confirmed negative influence of heavy tractor on soil structure.

Diplomová práce se zabývá problematikou bezpečnosti práce zemědělských strojů při pohybu na svazích. Analyzuje metody měření boční síly na svazích a zabývá se měřením boční síly u volného a bržděného kola na různých površích, v závislosti na tlaku vzduchu v pneumatice.

This master‘s thesis describes problematics of mathematical models of tires for computer simulations. The goal of this thesis is to depict currently used models of tires and to compare them. Thesis describes brush type models, Fiala, Magic Formula (Pacejka), FTire, UA-Gim, 521 and DELFT. Those models are compared to each other by simulations carried out in software MSC ADAMS Car. The results are shown in figures with commentary and evaluation. This thesis serves as introduction to problematics of currently used mathematical models of tire in computer simulations.