Table of Contents

  • THE EFFICIENCY OF AUTOMOTIVE VEHICLES BASED ON INTELLIGENT ONBOARD SYSTEMS

    pg(s) 14-17

    Broad automotive engineering in modern agricultural technologies results in the need to improve the operational characteristics of internal combustion engines. In this regard, the internal combustion engines are increasingly stringent requirements in terms of energy conservation and environmental safety. Improving the efficiency of operation of the engine is reduced to the complex optimization of the main variables and parameters of motors with absolute quality assessment used in these fuels. For a comprehensive optimization should be linked all the characteristics of the engine through certain values and parameters.

    When using fuels of different quality formulated problem is modeled as a multiobjective multi-parameter optimization. One way to solve this problem is the application of the guideline systematic approach – the principles of hierarchy. Management of automotive equipment by using on-Board devices, the functioning of which is considered at the level of subsystems of the engine. The basis for the partitioning of the engine on the levels is the structure, the relationship between the elements and features of their functioning.

    The interaction of the subsystems is reduced to the implementation of vehicle specified performance properties of the command signals from the electronic engine control systems. Decomposition of the hierarchical structure of the engine should be limited to three levels.
    During the development of the automated engine management system used in the dynamic system of the engine as the control objects, simulation, mathematical optimization techniques, special simulation setup and debug systems. In the result, we developed several technical solutions: automated system bench testing of engines and simulation of dynamic stand electronic control systems for internal combustion engines.

  • CONCEPT OF A NEW PRO ECOLOGIC MANIPULATOR OF THE SPECIALIZED TRACKED VEHICLE

    pg(s) 18-22

    This paper presents a new concept of the manipulator of the specialized tracked vehicle, designed within the project “WND- POIG.01.03.01-00-164/09 & UOD-DEM-1-145/011”, to be applied for conservation of the protected wetlands. The flail mower, cutting disk for trunks of the trees and/or new version of cutting head are to be interchangeably fitted at the end of the manipulator. It should be more functional in use and more efficient in cutting and removing small trees or bushes, or shredding them on spot. The new cutting head, described in this paper is dedicated to remove and transport branches of bushes, as well as single small trees with a diameter up to 140 mm and weight up 400 kgs on 3.2 m length arm. The paper presents the results of the kinetostatics and strength analysis of the virtual model of the new version of the manipulator. Real model of the new manipulator will be made from the steel S355 and its mass without tools should be around 350 kgs. The manipulator will be tested during field tests that are planned in the summer 2015.

  • DESIGN AND BULID VEHICLE WITH SOLAR DRIVE FOR WORLD SOLAR CHALLENGE COMPETITION

    pg(s) 23-26

    The paper shows problems and examples finishes solutions applied in the motor industry which be used by solar car production to competition World Solar Challenge. The subject matter will contains the mechanical matters connected with endurance of materials, the wheel set and aerodynamics as well as the electric questions relating the photovoltaic and conversion of electric energy on mechanical energy.

  • RECOMMENDATIONS ON CLIMATIZED CABINS AND SEATS

    pg(s) 27-29

    In view of the high risen demands on the machine operator to a safe and high efficient guidance the best possible "workplace situations" must be available. Beside assisted vehicle operation and ergonomically optimized machine interaction particular importance must be attended to individual adjustments as well as climate management. Though for a good climate in the cabin the newest technologies are applied, still the perceived comfort can become disagreeable in spite of air-conditioning. On longer terms the heat as well as the humidity produced by the driver accumulate in the seat and lead to negative sensations, concentration interferences, tiredness and consequently performance losses. Thus the operator’s seat sets a great challenge for agricultural and forestral automotive vehicles already in the matter of ergonomics and safety, concerning hygro-thermal functions however it is probably one of the most complicated development topic. Apart from general interactions between climate situations and best human work performance, assessment and measuring aspects for climate and comfort as well as constructional details for optimized heat and sweat management on drivers’s seats have to be respected.

  • EXPLOITATIONAL CHARACTERISTICS OF ELECTRIC VEHICLES

    pg(s) 3-7

    Various electric vehicles are exploited in Latvia. The paper analyses experimental data for three different electric vehicles: a Fiat Fiorino Electrico, a conversed automobile Renault Clio and a Think City. The paper focuses on the following parameters of the electric vehicles: charging parameters, range per charge and cost per charge. Lower cost per 100 km distance covered – EUR 2.91for conversed Renault Clio.

  • WORK SAFETY AND HEALTH PROTECTION IN MAINTENANCE AND REPAIR

    pg(s) 30-32

    Based on current stress situations in the repair section of a big German truck and bus company procedures for force measuring have been developed, methods for risk assessment are selected and applied and proposals for improvement of the work performance are discussed. In addition to the technical component of the force measurement with a specially designed device and the organizational component in a project with representatives of various disciplines the specific differences between service and production are to be respected. Most of the approved assessment tools like COBRA, KIM (LMM) or EAWS for physical work situations with critical body and spine loads can just be applied with restrictions. By use of a special documentation systematic the results of risk analysis of selected activities are evaluated and solutions developed according to the TOP principle with respect to economical, technical and organisational feasibility. Effort and practical acceptance of the project are mainly determined by the multidisciplinary staffed working group.

  • DETERMINATION OF THE FRICTION COEFFICIENT OF THE HEAVY-DUTY DISC BRAKES OF AGRICULTURAL VEHICLES

    pg(s) 8-13

    This article discusses the braking system of a heavy-duty engine for the determination of the friction coefficient. The agricultural vehicle progresses at 40 km/h speed; its weight is 30,000 kg. While braking such a heavy vehicle, a significant amount of heat is released as a result of the disc brake’s friction. A significant part of the resulting heat is removed from the system using oil cooling. The cooling oil lubricates the various components and affects the frictional conditions significantly.

    This article describes the construction of the braking system. It contains a description of the measurements on the test bench and the evaluation of the results. This study determines the frictional performance and describes the method for determining the friction coefficient of a given construction. The author shows the changes in the friction coefficient depending on the pressure and the temperature, and draws conclusions from the results.