Bringing the car into a skid is realised by the adhesion force decrease. This can be reached either by a coefficient of adhesion decrease or decrease of a radial reaction on the vehicle's wheel. For the purpose to the vehicle's behaviour change according to stability we chose the way of radial reaction change. To decrease the adhesion force transferred by the vehicle's wheels, the required part of radial reaction of a particular vehicle's wheel was transferred to the road, out of the vehicle's wheels, using additional auxiliary wheels. The auxiliary wheel units are connected to suspension arms. The article contains individual currently used ways for the adhesion force change and the unique way in the form of the system SlideWheel designed by the authors. The system SlideWheel, which was designed by the authors of this article, consists of three circuits. The first circuit is the mechanical part of the wheel unit, the second one is designed in the form of a hydraulic system and the third circuit is an electrical system used to control the wheel unit's lift through the hydraulic system. The system was designed to be used for experimental measurement purposes in education in order to experimentally simulate oversteer or understeer of the vehicle. The real measured data from a particular drive test are stated and evaluated in the conclusion. The measurement is implemented on a special experimental vehicle equipped with the SlideWheel system. Based on the experimental measurements, we have come to the conclusion that using the SW system, it is possible to change the adhesion force of a road vehicle.The paper deals with a new system for radial reaction change of vehicle wheels. This system has minimal added weight to the vehicle. At the same time, none of the components exceeds the ground plan of the vehicle. With the newly created system, it is possible to reduce radial reactions on any car wheel. The measured results are consistent with the vehicle's ride on sliding surfaces.

This article deals with the possibilities of adhesion force changes of a road vehicle. The authors present the possibilities of reducing the adhesion force of road vehicles and, at the same time, present their own system for changing the radial reaction of the vehicle wheels. This system removes the disadvantages of a commercially available SkidCar system. A representative road test is chosen in the article to determine the stability in a straight-line drive. Furthermore, the authors report the courses of characteristic parameters describing the behavior of a vehicle for driving a conventional car on a sliding surface and compared to the 50 % radial reaction of a vehicle driven with the SlideWheel on dry asphalt. It is clear from the measured runs that it is possible to change the adhesion force by changing the adhesion weight transmitted by the vehicle wheels. The use of the proposed SlideWheel system is possible for the purpose of verifying vehicle stability, while improving the driver's ability to operate the vehicle under reduced-adhesion conditions. The main goal of this paper is to design a system for reducing the adhesive force in an experimental car and perform experimental measurements.

This paper deals with the optimization of the crossbars, parts of the existing frame of the experimental system of the Alternative SkidCar. This part plays a crucial role and is designed to enable and ensure reduced adhesion conditions between the vehicle and the road. To this end, its optimization targeted here is performed using both analytical calculations and simulations in MSC Adams software, wherein the loading forces and boundary conditions on the frame support wheels are obtained considering the static conditions, as well as the change of the direction of travel. The least favourable load observed was used, later on, as the input value for the strength analysis of the frame. The analysis was performed using the finite element method (FEM) in SolidWorks. Based on the linear and nonlinear analyses performed, the course of stress on the frame arms and critical points with the highest stress concentration were determined. Subsequently, according to the results obtained, a new design for the current frame was proposed and, thereby, warrants greater rigidity, stability and strength to the entire structure, while reducing its weight and maximizing the potential of the selected material. The benefit of the current contribution lies in the optimization of the current frame shape, in terms of the position of weld joints, the location of the reinforcements and the thickness of the material used.

In this paper the authors discuss optimizing the key point of the subframe. The objective of the paper is to optimize the current design of the Alternative SkidCar frame. It is an auxiliary device, which attaches to the chassis of the car and allows controlled variation of the adhesion force transmitted between the wheels and the ground. The current form of the frame is assembled only from the point of view of functionality. The frame is obviously designed to make production as simple as possible. At the same time, it is oversized in terms of material. Optimization consists of finding a key construction node, which is the weakest point of the frame structure, while minimizing the weight, using the finite element method. Subsequently, we used the finite element method simulation for another material and we evaluated the current form of mechanical stress in this node, achieving a minimized weight. A new software study of the proposed design was subsequently performed. Based on the conclusions of the paper, the weight of the Alternative SkidCar frame was significantly reduced while respecting the required load capacity. Because the frame of the Alternative SkidCar is attached to the car as an accessory, it is desirable that it influences the vehicle's behaviour minimally. The change was made by reducing the thickness of the material profile and changing the material used. Just reducing the weight of the frameit is this change that has a significant positive effect on the behaviour of the car, complemented by the Alternative SkidCar system.

The Article deals with the controlled influence of the adhesive force in contact of the road vehicle's wheel with the road. The first section shows how the adhesive force is reduced. The next step is the familiarization with the experimental vehicle with the Alternative Skid-Car, where experimental measurements were carried out, assessment of the advantages and disadvantages of the experimental vehicle with the Alternative SkidCar and the drive on the sliding surface following the experimental test methods. The objective of the article is to determine how great the difference in vehicle behaviour is when the adhesive force changes by modifying the radial reaction and the change in the coefficient of adhesion.