## 2 Materials and Methods
#### Load Determination on the ASC Frame Arms  
To carry out a strength analysis of the frame ASC crossbar, an input load was determined, depending upon the experimental vehicle's weight, driving mode and the degree of vehicle weight support. The input load of the wheel units, when the vehicle was stationary, was determined by weighing in a step-change in the radial reaction on the vehicle wheels. The load under the centrifugal force that occurs at the center of gravity of the system during turns, was determined by simulation in MSC Adams 2020 (Figure 2). The coordinates of the experimental vehicle's center of gravity were determined by the weighing and rolling rotation of the car on the tilting platform. The procedure for determining the height coordinate is given in [32]. All model bodies have defined their self-weight, stiffness and other characteristics. The tires have defined the pliability and damping, which have been detected on the VVCD drum tire testing machine [33]. All pins have a defined internal friction. The vehicle body was replaced by a mass point placed in the car's center of gravity. The bodywork is linked to the vehicle axles via suspension, and to the SC frame via a fixed connection. At the ends of both ASC crossbars, wheel units with deformed tires are located on the rotational links. The deformation characteristic is given in [15]. The wheel units rotated freely on cylindrical pins (with defined internal friction) around their vertical axis. These pins allowed the wheel units to move vertically. In this way, it is possible to achieve a reduction in the radial reaction of the vehicle wheels. The mutual differences in the load on the support wheel units, in experimental measurements and simulation, are due to the fact that experimental measurements were defined by clearing down the clearances, and rubber components of the car chassis with the default value were used in the simulation model. The greatest error occurs when the tires are deformed at a low rate, especially at 20% of the car's unloading with SC, where the deviation is 5%. The average deviation is 2.2%, which can be considered as sufficient accuracy of  
Figure 1: (**a**)-Experimental vehicle with the ASC system, (**b**) frame ASC, and (**c**) crossbar ASC. the model. The comparison of the values obtained from the analytical calculation and the simulation values using MSC Adams together with the deviations, are depicted in Table 1.  
In order to determine the change in the radial reaction of the ASC wheel units, a simulation of the vehicle roll rotation on the tilting platform was carried out. Its inclination divides the force of gravity applied to the car into two components: the component perpendicular to the tilting platform and the component parallel to the tilting platform. The parallel force component with the surface of the tilting platform has similar effects to the centrifugal force when cornering and increases with the increasing angle of platform roll until the vehicle slips. At the same time, the second component of the force, perpendicular to the tilting platform, which determines the amount of adhesive force on the wheels of the car, decreases with the tilting. Further processing of measurements on the tilting platform is described in [32]. In the first three seconds of the simulation, the wheel units are raised to the desired value, followed by a time interval of 7 s to tilt the platform to a maximum value of \(\alpha\in<0^{\circ}\); 65\({}^{\circ}\)\(>\). The time course of tilting the platform is shown in Figure 3.  
Figure 3: Tilt platform progress—platform lift angle as a function of time. Figure 2: Vehicle model with ASC to determine the load. Simulations have been carried out for different load levels of the ASC wheel units (from 0% to 100% with a 20% step). A lift equal to zero radial reaction on the wheels is considered to be a 100% lift. The highest values achieved radial reactions on the front wheel units of the ASC at 100% lift and tilt.