The Master´s thesis deals with the engineering design of single-axle brakeless dump trailer for a tractor designed for transporting and dumping of particulate materials and firewood. The engineering design of the trailer is based on the proposed kinematic scheme and the basic calculations that are checked by FEM analysis in Ansys Workbench. The drawing documentation is done in AutoCAD.

Traction efficiency of tractors barely reaches 50 % in field operations. On the other hand, modern trends in agriculture show growth of the global tractor markets and at the same time increased demands for greenhouse gas emission reduction as well as energy efficiency due to increasing fuel costs. Engine power of farm tractors is growing at 1.8 kW per year reaching today about 500 kW for the highest traction class machines. The problem of effective use of energy has become crucial. Existing slip control approaches for tractors do not fulfil this requirement due to fixed reference set-point. The present work suggests an optimal control scheme based on set-point optimization and on assessment of soil conditions, namely, wheel-ground parameter identification using fuzzy-logic-assisted adaptive unscented Kalman filter.:List of figures VIII List of tables IX Keywords XI List of abbreviations XII List of mathematical symbols XIII Indices XV 1 Introduction 1 1.1 Problem description and challenges 1 1.1.1 Development of agricultural industry 1 1.1.2 Power flows and energy efficiency of a farm tractor 2 1.2 Motivation 9 1.3 Purpose and approach 12 1.3.1 Purpose and goals 12 1.3.2 Brief description of methodology 14 1.3.2.1 Drive torque feedback 14 1.3.2.2 Measurement signals 15 1.3.2.3 Identification of traction parameters 15 1.3.2.4 Definition of optimal slip 15 1.4 Outline 16 2 State of the art in traction management and parameter estimation 17 2.1 Slip control for farm tractors 17 2.2 Acquisition of drive torque feedback 23 2.3 Tire-ground parameter estimation 25 2.3.1 Kalman filter 25 2.3.2 Extended Kalman filter 27 2.3.3 Unscented Kalman filter 27 2.3.4 Adaptation algorithms for Kalman filter 29 3 Modelling vehicle dynamics for traction control 31 3.1 Tire-soil interaction 31 3.1.1 Forces in wheel-ground contact 32 3.1.1.1 Vertical force 32 3.1.1.2 Tire-ground surface geometry 34 3.1.2 Longitudinal force 36 3.1.3 Zero-slip condition 37 3.1.3.1 Soil shear stress 38 3.1.3.2 Rolling resistance 39 3.2 Vehicle body and wheels 40 3.2.1 Short description of Multi-Body-Simulation 40 3.2.2 Vehicle body and wheel models 42 3.2.3 Wheel structure 43 3.3 Stochastic input signals 45 3.3.1 Influence of trend and low-frequency components 47 3.3.2 Modelling stochastic signals 49 3.4 Further components and general view of tractor model 53 3.4.1 Generator, intermediate circuit, electrical motors and braking resistor 53 3.4.2 Diesel engine 55 4 Identification of traction parameters 56 4.1 Description of identification approaches 56 4.2 Vehicle model 58 4.2.1 Vehicle longitudinal dynamics 58 4.2.2 Wheel rotational dynamics 59 4.2.3 Tire dynamic rolling radius and inner rolling resistance coefficient 60 4.2.4 Whole model 61 4.3 Static methods of parameter identification 63 4.4 Adaptation mechanism of the unscented Kalman filter 63 4.5 Fuzzy supervisor for the adaptive unscented Kalman filter 66 4.5.1 Structure of the fuzzy supervisor 67 4.5.2 Stability analysis of the adaptive unscented Kalman filter with the fuzzy supervisor 69 5 Optimal slip control 73 5.1 Approaches for slip control by means of traction control system 73 5.1.1 Feedback compensation law 73 5.1.2 Sliding mode control 74 5.1.3 Funnel control 77 5.1.4 Lyapunov-Candidate-Function-based control, other approaches and choice of algorithm 78 5.2 General description of optimal slip control algorithm 79 5.3 Estimation of traction force characteristic curves 82 5.4 Optimal slip set-point computation 85 6 Verification of identification and optimal slip control systems 91 6.1 Simulation results 91 6.1.1 Identification of traction parameters 91 6.1.1.1 Comparison of extended Kalman filter and unscented Kalman filter 92 6.1.1.2 Comparison of ordinary and adaptive unscented Kalman filters 96 6.1.1.3 Comparison of the adaptive unscented Kalman filter with the fuzzy supervisor and static methods 99 6.1.1.4 Description of soil conditions 100 6.1.1.5 Identification of traction parameters under changing soil conditions 101 6.1.2 Approximation of characteristic curves 102 6.1.3 Slip control with reference of 10% 103 6.1.4 Comparison of operating with fixed and optimal slip reference 104 6.2 Experimental verification 108 6.2.1 Setup and description of the experiments 108 6.2.2 Virtual slip control without load machine 109 6.2.3 Virtual slip control with load machine 113 7 Summary, conclusions and future challenges 122 7.1 Summary of results and discussion 122 7.2 Contributions of the dissertation 123 7.3 Future challenges 123 Bibliography 125 A Measurement systems 137 A.1 Measurement of vehicle velocity 137 A.2 Measurement of wheel speed 138 A.3 Measurement or estimation of wheel vertical load 139 A.4 Measurement of draft force 140 A.5 Further possible measurement systems 141 B Basic probability theoretical notions 142 B.1 Brief description of the theory of stochastic processes 142 B.2 Properties of stochastic signals 144 B.3 Bayesian filtering 145 C Modelling stochastic draft force and field microprofile 147 D Approximation of kappa-curves 152 E Simulation parameters 156

The dissertation explores the work with harvester technology with a mobile traction winch in sloping terrains. It deals with the efficiency of these machines in their technological varieties. A time measurement study was undertaken in the dissertation which studied the work of a harvester with a mobile traction winch and without a mobile traction winch during the toll logging of a centennial spruce stand. The time study was performed in eastern Slovakia to establish the differences in time consumption during the work cycles. Some minor differences had been detected during work tasks, however, these did not exhibit any effect on the mobile traction winch in the work cycles of logging one tree. Furthermore, the time study measured the effect on any changes in work productivity, which is required during the operation of the mobile traction winch. Besides the harvester, a time study of a forwarder with a mobile traction winch has been compiled. To establish the effect on the forrest environment of the harvester technology and the mobile traction winch, an evalution of damage to the soil in two technological varieties was performed in Slovakia and the Czech republic. The technological variety with a mobile traction winch was less damaging to the soil surface due to the prevention of wheel slipping destpite the fact that the overall results of soil damage were negative. An operating cost analysis has been worked out to complete the study, which has shown the technological variety with the mobile traction winch to be more costly due to the purchase price of the winch and the higher fuel consumption. The main advantage, however, is safety, not cost savings.

This Master´s thesis deals with construction design of break system of the tractor Zetor Forterra HSX. At the beginning, there is an overview of different possibilities breaking system from other world´s producers of tractors. Afterwards there is constructional working from selection variant of suspension to final project. In this case the thesis contains required calculations of the whole device. Thesis also contains the stress and strain analysis of selected components of construction using a numerical approach of finite element method and drawing documentation of the selected components.

This diploma thesis deals with the strength and frequency analysis of tractor exhaust pipe, which is being developed as an economic alternative in the preparation of construction for use in convertible tractor’s in the Zetor Tractors company. First, modal analysis is performed to determine the natural frequency of the exhaust pipe. In the next section it deals with stress-strain analysis to assess the overall structural strength of the exhaust pipe. At the end is performed thermodynamic analysis to assess the thermal resistance. For these calculations was used the finite element method (FEM) using computing software ANSYS 13.

This diploma thesis is focused on compiling a computational model of the transmission of a Zetor Forterra HSX tractor in the Multibody software MSC ADAMS environment. It analyses the issue of creating gears in terms of vibration and noise. The thesis describes the creation of computational model which is used for simulation of the load conditions during tractor operation. The methodology is applied to a single-stage gearbox in which is verified. Then it is used on a model of a real tractor gearbox. The response of the input load conditions is projected during the forces in the engagement of the gears which are transmitted to the bearings.

The master thesis describes the methodology of laboratory and field measurements of tractors and tractor kits. It also contains graphical and tabular processing of measurement data and subsequent evaluation of the results obtained. It deals with the influence of power in the upper rod of three point hinge on wheel slip, work efficiency and fuel consumption.

Master’s thesis focuses on the specifics of agricultural machinery accidents. The introductory part defines agricultural machines and its basic characteristics. It also analyzes specific technical regulations that govern the use of these machines in traffic. The experimental part then describes the methodology and interprets the results of conducted experimental measurements on driving dynamics of a tractor with carried accessory. These measurements consist of a break test in straight line, evasion manoeuvre and acceleration while turning left. The focus was given to not just the acceleration values, but also to the influence of the carried accessory, the load on the front axle or the tire pressure. The analysis of the findings made compares the results with the driving dynamics of ordinary passenger cars and provides a detail dissection of the most frequent causes of agricultural machinery accidents.

This thesis deals with the installation of modern high pressure injection common rail system to six-cylinder tractor engine. This system replaces injection system with in-line fuel injection pump. Common Rail system installation on an existing engine is designed with minimal design changes to the engine block and engine head. It is advantageous to minimize production costs of the transition to high-pressure injection system. The thesis contains the design and stress analysis of the new component for high-pressure injection system.

This thesis presents a comparison of fuel consumption and transportation efficiency of various transport vehicles in primary agricultural production. The first part deals with the possibility of transport of materials in agriculture. The following is a description of the compared vehicles. Finally, it describes the methodology of calculation of fuel consumption vehicles, which are then compared.