## 2 Literature Review
[37], in which the authors assess the relation between the tire vertical load transfer and the center of gravity's height and immediate radius of the tire. Moreover, a Kalman-filter-based estimator was designed to simultaneously identify the center of gravity's height of a vehicle and the unknown nominal tire effective radius. Parameters and tire load are used for estimating the center of gravity's position also in publication [38], and it is necessary to have intelligent tires with a load sensor implemented in to calculate the position of the center of gravity [39; 40; 41]. Ref. [42] focuses on the issue of estimating the center of gravity's position while using the data from the tires as well. Such estimation is, however, related to several limitations, and the misestimation of the center of gravity's position using the above-mentioned method can reach up to 30% [43]. To estimate the position of the center of gravity, the method of total least squares is used [44]. The authors of Ref. [45] first estimated the weight of a vehicle based on the dynamic model of driving, and then, after estimating the weight and dynamic rolling model, they estimated the height of the center of gravity. As also mentioned in Ref. [46], estimating the position of the center of gravity by using this method is only possible in a certain range of accuracy, depending on many factors and the accuracy of other estimations. The authors of publication [47] focused on determining the center of gravity's height via experimental measurements, and they designed and used a device for measuring the moments of inertia of a vehicle. They were inspired by similar devices, such as \"VIMM\" [48], which can record, besides the moments of inertia, the center of gravity's position of vehicles in all axes, the vehicle mass, the moments of inertia towards the center of gravity as well as products of inertia, and \"VIMF\" [49]. \"VIMF\" can determine the same values as \"VIMM\" by using a principle of physical pendulum, and this leads to a change in oscillation period during the measurements. However, due to the motion of working fluids and vehicle suspension, the differences in the center of gravity's height reached more than 20% under the same conditions in each measurement [47]. Another method of experimental measurements is the measurements that consist of two steps. In the first step, the weight applied on the axes in the horizontal position is determined. Then, the weight applied to one of the axes when it is lifted is determined [50]. To ensure the highest accuracy possible, it is appropriate to use this method when the fuel, washer fluid, and other tanks are empty or full, as also follows from Ref. [51]. On the other hand, the disadvantage of this method can be high requirements for measuring devices, such as measuring stand and, predominantly, the scales with sufficient load capacity that equals the minimum axle load of a vehicle--at least 1500 kg--while at the same time having the highest accuracy possible, with a measurement deviation of less than 1 kg, which all increase the costs for equipment as well as the requirements for operation [52; 53]. It is also necessary for this method to have lifting equipment for the axle, for instance a pillar jack since, as mentioned in publication [54], the angle between the axes should be at least 15\({}^{\circ}\), which also increases the requirements for the equipment. Many publications [55; 56; 57; 58; 59] consider only an empty vehicle. Publications in which the load in the vehicles is also considered are almost non-existent. Experimental measurements with a roof box, since as also mentioned in one of the few publications in which the experimental measurements with the roof box were performed [60], the method of least squares estimated the center of gravity's height with a deviation higher than 10%, which is insufficient accuracy. As identified in the text above, a measurement methodology which is sufficiently accurate and relatively less demanding in time, material, and expenses is highly needed.