## 1 Introduction
The analysis of references [1; 2] regarding the weight-aligning torque at the combined kingpin angle proved that only the dependence given in [1] allows us to determine this torque by the expression:  
\[\mathrm{M}_{st}(\theta)=R_{z}(l_{k}-r_{w}tg\gamma_{k})\big{[}\mathrm{cos}( \alpha_{k}+\gamma_{k0})\mathrm{sin}\alpha_{k}\mathrm{sin}\theta\pm\mathrm{cos} (\beta_{k}+\gamma_{k0})\mathrm{sin}\beta_{k}\mathrm{cos}\theta\big{]} \tag{2}\]  
where \(R_{z}\) is the normal reaction to the steered wheel, N; \(l_{k}\) is the knuckle length, m (the knuckle length is defined here as the distance between the wheel spin axis intersection points with the kingpin axis and the wheel plane); \(r_{w}\) is the dynamic radius of the wheel, m; \(\alpha_{k}\) is the kingpin inclination angle, deg; \(\beta_{k}\) is the caster angle, deg; \(\gamma_{k0}\) is the camber angle when moving in a straight line (\(\theta=0\)), deg; and \(\gamma_{k}\) is the current camber angle at the combined kingpin inclination angle, which is determined according to the dependence [1]:  
\[\gamma_{k}=\gamma_{k0}+\alpha_{k}(1-\mathrm{cos}\theta)\pm\beta_{k}\mathrm{ sin}\theta \tag{3}\]  
Note that in Formulas (2) and (3), the \"plus\" sign should be taken when the knuckle of the left wheel is turned to the left from the neutral position, and the right wheel--to the right when the caster angle is positive. In the opposite case, take the \"minus\" sign. At the same time, it is considered that the weight-aligning torque with a \"plus\" sign rotates the steered wheel to the position of rectilinear movement, creating resistance to steer the wheel from the position of rectilinear movement about the kingpin axis. Since the maximum tire steering resistance torque occurs when the wheel steers in static state and is decisive for the calculation of the power steering, special attention was paid to its determination [1; 2; 11; 12; 13; 15; 16]. The analysis of references [1; 2; 11; 13; 16] proved that the tire steering resistance torque in these works is considered for a locked wheel. A locked wheel is a wheel that does not roll on the support surface when steering (does not spin about the knuckle axis). In this case, the steered wheel together with the knuckle is a complex mechanism, and when the wheel is steered in static state, the tire contact patch rotates about the point where the kingpin axis intersects the support surface. At the same time, the value of the static tire steering resistance torque is a function of the steer angle, the load on the wheel, the tire contact patch dimensions, the position of the kingpin axis--support surface intersection point, and the friction coefficient between tire and support surface. As for the kingpin axis--support surface intersection point, for most wheeled vehicles it is within the tire contact patch. The course of dependence \(M_{\varphi}=f(\theta)\) has a complex character. In [15], it is noted that the torque applied to the steered wheel first overcomes the twisting of the sidewall of the tire with a slight sliding of the tire contact patch on the support surface, and then reaches the value at which the tire contact patch completely slides on it. In [13], the movement of the tire during static steering is divided into two processes: elastic deformation of the tire and sliding of the tire contact patch on the support surface. In case of elastic deformation, the static tire steering resistance torque is directly proportional to the steer angle. The steering resistance torque during the sliding of the tire contact patch on the support surface does not depend on the steer angle. At the same time, these works do not indicate at which steer angles a certain stage of wheel rotation occurs. The analysis of the experimental dependencies of the truck tire steering resistance torque \(M_{\varphi}\) on the steer angle \(\theta\) given in [1,2] showed that the dependence \(M_{\varphi}=f(\theta)\) can be conditionally divided into three sections. The first is a section of the conditional linear dependence of the torque \(M_{\varphi}=f(\theta)\).