PSI - Issue 77

Francisco Castro et al. / Procedia Structural Integrity 77 (2026) 611–630 Francisco Castro/ Structural Integrity Procedia 00 (2026) 000 – 000

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Table 3 – CoG height estimation for the braking movement and respective error in measurements related to the static measurements.

real [m] estimation [m]

Absolute error [m]

Percentage error [%]

Vehicle

Load case: empty

0.102 0.103 0.105 0.107 0.119 0.117

0.106 0.108 0.100 0.102 0.114 0.120

0.004 0.005 0.005 0.005 0.005 0.003

4.470 5.325 4.311 4.925 4.165

Load case 1 Load case 2 Load case 3 Load case 4 Load case 5

2.631 The CoG height estimation error remained within 5%. This confirms the method’s resilience to moderate mass redistributions, particularly those affecting the longitudinal CoG coordinate , but not the vertical position. These results demonstrate that the proposed method can estimate the vehicle’s CoG height under dynamic braking with high accuracy and minimal sensitivity to minor variations in vehicle loading, making it a suitable candidate for

integration into active safety or rollover prevention systems. 3.2.2. CoG height measurements: cornering motion results Roll-center height measurements

The determination of the roll center position is essential, particularly the height position, for the cornering in motion approach. Therefore, the roll center height of the vehicle was determined using a purely geometrical approach, based on the suspension layout. This method consists on analyzing the positions of the suspension arms and their projected lines in the transverse vertical plane to identify the instant center of rotation. The roll center is then defined as the point at which the line connecting the instant center intersects th e vehicle’s centerline. By applying this procedure to the front and rear suspension geometries, the roll center heights were obtained, providing a direct measure of the suspension’s influence on lateral load transfer and body roll characteristics. Figure 14 provides all the measurements for the determination of the roll center height position.

a)

b)

c)

f)

d)

e)

Figure 14 – Roll-centre height measurements: a) empty; b) load case 1; c) load case 2; d) load case 3; e) load case 4; f) load case 5.