No abstract

Conducting laboratory and field testing is a classic approach to the development and certification of vehicles and their automotive components. These processes are costly and time-consuming. The serial installation of mechatronic systems in the car forced software and electronic systems engineers to master a new approach to testing and development -"physical" simulation (Hardware-in-the-loop). The aim of the research in this article is to develop, implement and validate a "physical" simulation method for evaluating the performance of Electronic Stability Control (ESC) systems. In this research, an ESC HIL-testbench, a mathematical model of the vehicle curvilinear movement in Adams Car, and a method for converting it into a Simulink-model, that allows generating a C-code, were developed and implemented. To assess the adequacy and correctness of the "physical" simulation, full-scale dynamic manoeuvres were carried out on the object of research -the Gazelle Next vehicle with ESC-system "Bosch ESP 9.1". In this article, the results of road tests and simulations, as well as an assessment of their convergence, are presented in tabular and graphical forms. The maximum discrepancy was 19% with the maximum allowable one up to 25% in accordance with the standard ISO 19635.

We present a suspension design the elastic elements of which are made of elastomers. This allows us to reduce the weight of unsprung parts of the vehicle significantly, which affects the quality of ride in a positive way. The aim of the study is to determine the elastic characteristic, the damping coefficient, the natural oscillation frequency of the sprung masses and the specific dynamic energy intensity of the suspension with elastomeric elastic elements. The determination of these parameters is carried out on the basis of experimental data got as a results of static and dynamic loading of a package of elastomeric elements. The elastic characteristic of the elastomeric element is obtained by static reduction and is not linear. Stiffness estimation of an elastomeric element for a specific point of characteristic or for a limited area is suggested. Also, there are significant friction losses during deformation, it is quite difficult to take them into account as a separate parameter when evaluating the elastomer damping properties. It is recommended to estimate their absorption capacity using a “conditional” damping coefficient. Its value is determined by the nature of the damped oscillations process under dynamic loading of an elastomeric elements package implemented on a special pendulum copra. The method of reducing the elastic characteristic and the damping coefficient of the elastomer to the “wheel” using graphoanalytic techniques is described in detail. The values of natural oscillation frequency and the energy intensity of the suspension with elastomeric elastic element are calculated based on the values of the suspension static and dynamic deflections and the forces in the tire contact with the supporting surface. Relying on experience in analyzing the standard car suspension parameters, it is concluded that using elastomeric elastic elements in the suspension design of trucks, buses and all-terrain vehicles is advisable.

Suspension structure, its elastic elements made of elastomers, is described in the paper. This allows to considerably decrease a vehicle’s unsprung weight improving its ride quality. The research is aimed at determining elastomer elastic element’s damping impact on a vehicle’s smooth ride quality. The impact estimate was carried out by comparing simulation modelling results of GAZelle NEXT vehicle’s front suspension and an equivalent suspension with an elastomer elastic element. Dual-mass single-axle suspension model was chosen as a calculation model. The modelling was performed in MATLAB/Simulink software package. Standard suspension key parameters, that is spring rate and shock absorber resistance characteristic, were experimentally obtained for each vehicle. Elastomer element elastic response was obtained at static necking and averaged with respect to loading and unloading characteristics. Damping capacity was estimated basing on the damped oscillations process realized on a special pendulum impact testing machine. “Relative” elastomer damping coefficient was calculated. All the measured parameters were reduced “awheel” by grapho-analytical methods. Vibration acceleration root-meant-square values (RMS) on the car frame and normal awheel response of a vehicle’s motion under various speed conditions over smooth cobbled road served as assessment criteria. Roadbed microprofile mathematic model was realized basing on superposition harmonic function method with various oscillations frequency and amplitude. Analytical findings reveal that a standard suspension with a cylindrical spiral spring and a hydraulic shock absorber outperforms the elastomer elastic element structure in all the given motion modes with respect to the ride quality criteria. The research findings bring about the conclusion that elastomers lack visco-elastic characteristics necessary to provide better ride quality compared to the standard suspension structure.