Poprawa komfortu kierowcy poprzez dobór optymalnego resorowania fotela

Two algorithms which allow one to take an uneven road surface into account in the vehicle dynamics analysis are presented in the article. Their essence is to determine the position of the contact point of the tire model with the uneven road surface. According to the concept of the authors, the names of the algorithms are to refer to the essence of the matter of the procedures assumed. The first of them – named Plane – can be used while considering the continuous model of the surface obtained by use of “the bicubic interpolation” taken from computer graphics, and the second one – named 4Points – in the case of the discrete model of this surface, developed especially for needs of the methods presented. In the work, it is assumed that only continuous changes of the road profile, without its possible abrupt changes, e.g. in form of a transversely placed threshold of sharp edges, can be considered. Therefore, the mapping of the road surface, obtained in the case of including its both models, is smooth. The developed algorithms are used to analyze dynamics of a technical rescue vehicle which can drive in terrain conditions.

Computer simulations of vehicle dynamics become more complex when a vehicle movement takes place on the uneven road surface. In such a case two problems must be solved. The first one concerns a way of road surface modeling, and the second one a way of precisely determining a place of interaction of reaction forces of the road on the vehicle wheels. In this paper triangular irregular networks (TIN) surface was used for modeling surface unevenness, and the author’s algorithm based on the efficient kd-tree data structure was developed for determining a place of an application road surface reaction forces. For calculating the reaction forces including rolling resistance force the Pacejka Magic Formula tire model was used. The solution presented in the paper is computing efficient and for this reason it can be used in the in real-time simulations not only for a vehicle dynamics but for any objects moving over an uneven surface road.

The paper presents dynamic optimization methods used to calculate the optimal braking torques applied to wheels of an articulated vehicle in the lane following/changing maneuver in order to prevent a vehicle rollover. In the case of unforeseen obstacles, the nominal trajectory of the articulated vehicle has to be modified, in order to avoid collisions. Computing the objective function requires an integration of the equation of motions of the vehicle in each optimization step. Since it is rather time-consuming, a modification of the classical gradient method—variable metric method (VMM)—was proposed by implementing parallel computing on many cores of computing unit processors. Results of optimization calculations providing stable motion of a vehicle while performing a maneuver and a description and results of parallel computing are presented in this paper.

In this paper a hybrid optimization method consisting in conjunction an evolutionary algorithm and a classical optimization method has been presented. This hybrid method has been used to select the parameters of a driver's seat of a special vehicle, which contributes directly to increase in driving comfort. A brief description of a vehicle mathematical model was formulated by using joint coordinates and homogenous transformations. Numerical simulations of optimization and dynamics have been performed over obstacles in a form of a speed bump. A subject of the investigations was to select such damping parameters to minimize amplitudes of driver's seat vibrations.