## 4 Results
### Gearshift Map
The graphic representation shows the characteristics of the traction force \(F_{t}\) for different power requirements represented by the accelerator pedal position level, with the 0.0 value corresponding to the minimum and 1.0 the maximum fuel delivery. The characteristics of values at chosen specific points related to the 30%, 40%, 60%, 90% and 100% power requirement are shown. To increase the readability of the graph, the characteristics of other values representing the dynamic properties of the vehicle and the fuel consumption are not shown. Nevertheless, these values influenced the dynamic characteristics of the vehicle and, of course, also speeds at which the gearshift is performed upwards (blue lines) and downwards (red lines), considering the accelerator pedal position. These assumed values are shown in the idealized two-dimensional gearshift map. Figure 17: (a) External engine revolution characteristics; (b) brake-specific fuel consumption (BSFC). Figure 18: Gearshift map. The ideal moment for the gearshift can be assessed from many different points of view. However, in the operation of civilian and military vehicles, the priorities, driving conditions and situations are usually different. Furthermore, the particular curves shown in the gearshift map depend on a large number of variables, and it is impossible to meet all requirements. In addition to the fundamental critical parameters that are usually monitored and evaluated during the search for ideal gearshift areas, for example, power, torque, fuel consumption or revolutions, other parameters can also be analyzed. The transmission control unit logic can be created to achieve the maximum vehicle acceleration values, the highest possible gearshift quality or to obtain the maximum comfort. For the TCU model creation, it was necessary to implement the gearshift map into the Matlab environment through two blocks of two-dimensional lookup tables performing interpolation and index searching in the Simulink environment (Figure 20). The two-dimensional lookup tables represent functions of two variables, and their task is to create a threshold signal for upshifting and downshifting. The table providing upshifting was defined by the coordinates of the gearshift gear vector [g_up], the accelerator pedal position level corresponding to the demand on the power [dem_up] and the up-gearshift threshold [v_up]. The second lookup table providing values for the down gearshift was defined in the same way considering the values of the gear vector [g_down], the accelerator pedal depression level (power demand) [dem_down] and the downshift threshold [v_down]. The vehicle speed and the selected gear are the inputs of both tables. Figure 19: Primary gearshift map. Figure 20: The 2D interpolation tables generating gearshift thresholds. Subsequently, based on the input values and vectors defined in the table, the threshold values for upshifting (up_th) and downshifting (down_th) are determined and assigned using the interpolation algorithm. In the graph in Figure 21, a graphic representation of the assigned boundary values for the primary gearshift map created in the Matlab environment is shown. Based on the graphical representation of the values for the change in the gear and the vehicle velocity \(v\), it is possible to explain the gearshift map principle (Figure 22). If the current vehicle speed is higher than the limit value for upshifting, a higher gear is selected, and similarly, if the current speed is lower than the limit value for downshifting, a lower gear is selected.