• TRANSPORT. SAFETY AND ECOLOGY. LOGISTICS AND MANAGEMENT

    Qualitative traffic indicators analysis and optimization model for traffic operations in urban zone

    Trans Motauto World, Vol. 7 (2022), Issue 3, pg(s) 110-114

    The greater interest of people living in urban areas has been accompanied by an increase in demand for motorized movements and other forms of active movements in these areas. As a result, traffic problems have been increased extremely for these road users both in terms of the quality of movement and safety. This research is focused on identifying factors related to the quality of motori zed and nonmotorized movements in urban areas, a particular case study of the municipality of Fushe Kosova, and the design of a model for traffic optimization in urban areas. The current approach to prioritizing the solution of motorized traffic problems, especially in d eveloping countries, has proved ineffective because, in the absence of addressing other mobility requirements (pedestrian, cyclist mobility), road users have been encouraged more to use this form of transport, leaving no room for other alternatives. The research aims to apply advanced methods for handling and managing traffic problems based on the principle of inclusion and building a model for optimizing traffic operation based on a specific case. The model is built using the programming language “Synchro,” which enables the analysis, optimization, and simulation of all forms of transport: motorized traffic, movement of pedestrians and cyclists in the road network planned following these requirements. Obtained results show the advantages of using different forms of transport depending on the selected concept and the priority of certain forms of transport. The summary results and their comparison in terms of quality for different time intervals, including the different conditions of access to urban areas, are presented in tabular forms.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    A design and stand tests of real-time vehicle active suspension

    Trans Motauto World, Vol. 6 (2021), Issue 4, pg(s) 116-119

    The paper deals with innovations in vehicle suspension technology developed in the Josef Bozek´s Research Center of Combustion Engines and Automobiles at CTU in Prague, Czech Republic. A unique innovative suspension system that uses a linear electric motor as a controlled actuator has been designed. Many experiments on the energy management in the system have been accomplished. In order to verify various control strategies and to test different ways of energy consumption optimization we designed and constructed a unique onequarter- car test stand. To realize simulation and practical experiments at the test stand it is necessary to find a proper experimental road disturbance signal to excite the active suspension system. The disturbance signal is applied on one more linear motor that is placed under a wheel of the one-quarter-car test stand to excite the active suspension system. The paper deals with the way and results of experimental verification of vehicle active suspension behavior when robust control is applied and also with energy management strategy that is used in the system. A modified H-infinity controller that enables to set energy management strategy is mentioned in the paper. At the close of the paper, some experiments taken on the one quarter-car model and their evaluation are discussed.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    Structure of the Model of Hybrid Electric Vehicle Energy Efficiency

    Trans Motauto World, Vol. 6 (2021), Issue 3, pg(s) 76-79

    The hybrid electric vehicles (HEV) are promising vehicles with low exhaust emissions and increased autonomy of movement including internal combustion engine (ICE) and electric motor (EM) which is powered by the battery (B) . The main advantage of HEV over classic cars is the reduced fuel consumption, especially in urban traffic [1]. This is a prerequisite for good energy efficiency of HEV, which is determined by the fuel consumption and consumption, respectively the regeneration of electricity of HEV. These values depend on many factors such as speed, mileage, acceleration, mass, drag, climatic conditions and more. The modelling of the energy efficiency of HEV is related to the study and structuring of the factors that determine the fuel consumption and electricity consumption and the dependencies between them and their connection and construction in a model. The model of energy efficiency of HEV gives a quantitative assessment of the fuel consumption and the consumption (regeneration) of electricity of HEV, according to the main influencing parameters. In addition, the HEV energy efficiency model indicates the influencing parameters and their analytical or experimental determination. The correct modelling of energy efficiency is related to the correct determination of energy parameters and their logical connection in a selected model. The optimal model of energy efficiency of HEV is built from these factors that can be directly measured or calculated, which increases the accuracy and reliability of the results. This article discusses building an energy efficiency model of a hybrid electric vehicle.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    On electromagnetic actuator control in the active suspension systems

    Trans Motauto World, Vol. 5 (2020), Issue 1, pg(s) 6-9

    In the paper, the design of a linear motor as an actuator in vehicle active suspension systems will be presented. The attention is focused on several interesting design aspects of a non-traditional actuator (a linear synchronous permanent magnet motor with electronic commutation) controlled to obtain a variable mechanical force for a car active suspension. The main advantage of such a solution is the possibility to generate desired forces acting between the unsprung (wheel) and sprung (car body) masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances it is possible to reduce or even eliminate the demands concerning the external power source.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    Energy control principles in an automotive active suspension system

    Trans Motauto World, Vol. 4 (2019), Issue 3, pg(s) 107-110

    In the paper, energy recuperation and management in automotive suspension systems with linear electric motors controlled using a proposed H∞ controller to obtain a variable mechanical force for a car damper is presented. Vehicle suspensions in which forces are generated in response to feedback signals by active elements obviously offer increased design flexibility compared to the conventional suspensions using passive elements such as springs and dampers. The main advantage of the proposed solution using a linear AC motor is the possibility to generate desired forces acting between the unsprung and sprung masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances using linear motors as actuators enables to transform mechanical energy of the vertical car vibrations to electrical energy, accumulate it, and use it when needed. Energy flow control (management) enables to reduce or even eliminate the demands concerning the external power source.

  • INNOVATION POLICY AND INNOVATION MANAGEMENT

    Limitations to suspension performance in a two-degree-of-freedom car active suspension

    Innovations, Vol. 7 (2019), Issue 3, pg(s) 111-114

    It is often assumed that if practical difficulties are neglected, active systems could produce in principle arbitrary ideal behavior. This paper presents the factorization approach that is taken to derive limitations of achievable frequency responses for active vehicle suspension systems in terms of invariant frequency points and restricted rate of decay at high frequencies. The factorization approach enables us to determine complete sets of such constraints on various transfer functions from the load and road disturbance inputs for typical choices of measured outputs and then choose the “most advantageous” vector of the measurements from the point of view of the widest class of the achievable frequency responses. Using a simple linear two degree-of-freedom car suspension system model it will be shown that even using complete state feedback and in the case of in which the system is controllable in the control theory sense, there still are limitations to suspension performance in the fully active state.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    A SKY-HOOK CONTROL CONCEPT OF VEHICLE ACTIVE SUSPENSIONS

    Trans Motauto World, Vol. 3 (2018), Issue 3, pg(s) 106-110

    In the paper, fuzzy logic is used to simulate active suspension control of a one-half-car model. Velocity and acceleration of the front and rear wheels and undercarriage velocity above the wheels are taken as input data of the fuzzy logic controller. Active forces improving vehicle driving, ride comfort and handling properties are considered to be the controller outputs. The controller design is proposed to minimize chassis and wheels deflection (sky-hook concept) when uneven road surfaces, pavement points, etc. are acting on tires of the running car. As a result, a comparison of an active suspension fuzzy control and a spring/damper passive suspension is shown using MATLAB simulations.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    MULTISTAGE GEAR PROJECT OF THE ELECTRICAL CAR SGR2016 FOR THE SILESIAN GREENPOWER ORGANIZATION

    Trans Motauto World, Vol. 3 (2018), Issue 1, pg(s) 3-6

    The subject of the paper, titled ‘Multistage Gear Project Of The Electrical Car SGR2016 for the Silesian Greenpower organization’, is an analysis of a chain vibrations in drive gear of SGR 2016 bolide. The exact moment of gear switch presents the greatest threat of a stability loss. Tests have been conducted in 2 stages. The first stage was the determining of derailleur setting. The adjusted component was a mechanism responsible for increasing the drag movement of derailleur cage. Adjustment of this element caused change in vibration characteristics in different system parts. That element was adjusted so oscillations were minimized. The second stage of studies was pinpointing the correct rotational speed, at which gears should be changed, using previously defined derailleur adjustment. Speed, at which the gear switch takes place, was chosen so the vibrations are lowest possible. Oscillation amplitude was recorded using high speed camera, and the data was analyzed using a dedicated High Speed AVI software. Speed measurement had been done using magnetic field sensor. All studies have been conducted on inertial system, simulating real life race conditions. Comparing all results, optimal driving parameters in terms of drive gear work stability, have been defined.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    OPTIMAL CONTROL OF QUARTER CAR VEHICLE SUSPENSIONS

    Trans Motauto World, Vol. 2 (2017), Issue 5, pg(s) 184-186

    This paper deals with the comparison of Control of quarter car vehicle suspension using Linear Quadratic Regulator (LQR) and Fuzzy Logic Controller (FLC) which are considered to control quarter car suspension and computer simulation is done on the nonlinear quarter-car model with actuator dynamics. The Linear Quadratic Regulator (LQR) and Linear Quadratic Gausian (LQG) methods are the most used control approaches. LQR and FLC provide the possibility to emphasize quantifiable issues of vehicle suspensions like; ride comfort and road holding for varying external conditions.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    VIBRATION CHARACTERISTICS OF QUARTER CAR SEMI-ACTIVE SUSPENSION MODEL – NUMERICAL SIMULATIONS AND INDOOR TESTING

    Trans Motauto World, Vol. 2 (2017), Issue 1, pg(s) 11-16

    This paper describes the results of numerical simulations and laboratory experiments of quarter car semi-active suspension model. Elastic characteristic of the coil spring and damping characteristics of the shock absorber in various operating modes are determinate. The amplitude-frequency characteristics and transfer function of the system with various damping coefficient are obtained. The results can be used to design semi-active suspension control strategy for improving ride comfort and road holding of ground vehicles.

  • CREATION OF ACCUMULATION AND STORAGE OF ELECTRICAL ENERGY FOR DRIVERLESS ELECTRIC VEHICLES OF RUSSIAN PRODUCTION

    Trans Motauto World, Vol. 1 (2016), Issue 1, pg(s) 18-21

    In recent years, many researches in the field of electromobile transport using as driverless vehicle are carried out in Russia as in the world. Operation electromobile transport in Russia has specific features, among which are the cold climate and heavy traffic conditions. One of the key elements of the functioning of electromobile transport is an energy storage system, the characteristics of which are highly dependent on how and under what conditions the vehicle is operated. The life of the energy storage system is also adversely affected by high temperature and short overvoltage on its elements. To increase the mileage of vehicles on the electric energy storage provides an improved system design, and in this article the experience of creating such an energy storage system for the driverless vehicle, taking into account including the Russian operating conditions. In the process of creating energy storage system were carried out calculations, mathematical and natural layout the basic elements of the system.

  • A METHOD OF VEHICLE-PEDESTRIAN ACCIDENT RECONSTRUCTION

    Trans Motauto World, Vol. 1 (2016), Issue 1, pg(s) 7-9

    In this work a method of vehicle-pedestrian accident reconstruction in case of unlimited driver visibility and accelerating vehicle moving is presented. This method presents are mathematical models for determining the pedestrian visibility time, vehicle speed at the moment of impact, time to vehicle move from the moment of the hazard occurrence until the moment of impact, the vehicle distance from the place of impact, stopping distance, etc.