2nd ICAI 2022

International Conference on Automotive Industry 2022

Mladá Boleslav, Czech Republic

3.2 Schematisation The measured torque progress was schematized using two-parameter schematization – torque on the input shaft and engine speed (= gearwheels revolutions) following the procedure: a) In the first step, it was necessary to determine the maximum and minimum values of moments and revolutions, and then the number and setting of levels were selected, for which the schematization will be carried out. 41 levels were selected, with the centre of one level being zero. b) Subsequently, the histogram for these levels was calculated, with the fact that it was first the number of recorded samples falling into the respective torque speed combinations. c) Since the records were sampled with the same time sample, it was possible to convert this table from the number of samples to the number of shaft revolutions. d) Such schemes were carried out separately for each gear, for the input and output from the gearbox (here it was necessary to change the torque and speed levels). This data is displayed more clearly in the following bar charts (Fig. 9), for the examples with torque moment from the engine (on the left) and for the moment of engaging the third gear (on the right). e) In the next step, it was possible to add up all the numbers of revolutions for each torque moment and thus obtain the resulting number of revolutions of the shaft or relevant gearwheel for each torque moment level. This resulting schematization was quantified as absolute (that is, the number of revolutions for a given level) or as relative, where frequency means the relative (“percentage”) share of the entire journey and the sum of the frequency is 1 (Figure 10).

Figure 9: 3D illustration of two-parameter schematization

Source: own elaboration (2022)

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