The reconstruction of a road accident can be treated as the resolution of an "inverse problem" in mechanics using analytical or numerical models. In the road accident reconstruction research, an assumption is often made that a predominant part of the energy lost during vehicle collisions is consumed by permanent deformation of vehicle components. Other parts of the dissipated energy can be ignored due to their insignificant amount. In this article, this assumption will be verified for the front-to-side collision of passenger cars. The main objective of this paper is to determine the important components of the energy balance dissipated during the collision. These components were determined on the basis of experimental results, which included three crash tests with a front-to-side collision of motor vehicles of the same make and model, with the right-angle impact of one car against the side of another. The results of experiments were used to construct the model of the dynamics of the motor vehicle collision. The model was then used as a basis for the determination of the forces, displacements and velocities during vehicle collision. The above made it possible to determine vehicle force/deformation curves and then M. Gidlewski (B) the key components of the dissipated energy in function of the duration of the contact phase of the vehicle collision. Based on the results of the model and crash tests, conclusions were formulated that provide an important insight into the reconstruction of the front-to-side collisions of motor vehicles.

The article shows the validity of four-wheel steering (4WS) bicycle model. At the beginning it is presented in which tasks, connected with 4WS vehicles, the bicycle model is applied. Then the equations in local coordinate system and their forms in global coordinate system are presented. The research tested the response of the model to a lane change manoeuvre, using transfer functions and a “bang-bang” control signal. The transfer functions was connected with static ratio characteristic to construct full four-wheel steering model. A reference signal generator and vehicle model were constructed in analytical form and checked in Matlab&Simulink using sample vehicle’s data from another literature item. One example of simulations was shown. The results presented led to interesting conclusions and indicated directions for further research. This research will include the issue of regulators derivation. This will allow for the construction of a fully functioning control system. The effects of this activities will be tested again in simulation environment.

This article presents fragments of authors’ research works regarding the automation of the process of lane-change manoeuvre by a car. The mathematical model of the conceptual automatic control system was elaborated on the basis of the simplified ‘bicycle model’ of a car’s lateral dynamics. From a theoretical point of view, the controller’s algorithm seems to be very efficient but of course it requires testing with a car in many operating conditions. Such investigations could be carried out using a very detailed model of the vehicle’s motion treated as a virtual object of control. The purpose of extensive simulation investigations was to check the controller’s operation and evaluate its sensitivity to changes in the vehicle and road parameters. This article presents unpublished results of studies on the sensitivity of errors in measured signals. In simulation-based sensitivity investigations, special sensitivity indexes support this analysis. The analysis provides more reliable conclusions about the performance of the controller and shows the required accuracy of the measured signals. The article presents information on the models, the method used and the sample research results. The presented method of automatic control and its testing method can be an attractive proposition for designers and researchers of active steering systems that enhance the active safety of vehicles.

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