# Accelerometer-Based Pavement Classification for Vehicle Dynamics Analysis Using Neural Networks
## 3 Results
This  
Figure 5: The acceleration variations on a concrete cube pavement with regular intervals: (**a**) the acceleration graph; (**b**) an example of the surface. may suggest that the vehicle has completed traversing the most arduous section of the roadway, or that the velocity has diminished, resulting in fewer oscillations. Stone pavement generates consistent although sometimes unpredictable vibrations that particularly impact the unsprung mass. Each stone in the pavement generates varying intensities of shock based on its dimensions and placement. This indicates that the vehicle's wheels are perpetually subjected to varying shocks, necessitating a rapid response from the suspension to continuously fluctuating irregularities. Consequently, the level of driving comfort on such a surface is significantly diminished, and the frequent and pronounced acceleration fluctuations seen in Figure 6 illustrate this dynamic load. The stone pavement induces persistent, moderate-intensity splits to the vehicle, resulting in discernible although irregular acceleration spikes. The elevated oscillation frequency shown in Figure 6 signifies that this pavement produces substantial data for the accelerometers, and its irregular vibration patterns are crucial for the analysis and classification of pavement types based on the accelerometer data. Figure 7 illustrates the acceleration of the vehicle's vertical sprung mass when traversing Belgian cobblestone. This pavement has an irregular surface composed of bigger, inconsistently spaced stones, often seen in historical urban thoroughfares or historic areas. In contrast to traditional stone pavements, Belgian paving has deeper interstices between the stones and more pronounced changes in surface texture, resulting in heightened and more powerful vibrations. Figure 6: The dynamic response of vertically sprung mass on a cobblestone pavement: (**a**) the acceleration graph; (**b**) an example of the surface. Figure 7: Vertical acceleration analysis on a Belgian cobblestone surface: (**a**) the acceleration graph; (**b**) an example of the surface. Initially, between 0 and 0.25 s, minor fluctuations in acceleration are seen, ranging from \(+50\) m/s\({}^{2}\) to \(-50\) m/s\({}^{2}\). This signifies that the vehicle is either approaching a section of stone pavement or traversing a less severe portion of this surface. Throughout this interval, the vibrations are comparatively less; yet, it is evident that the surface influences the vehicle's dynamics. After 0.3 s of acceleration, the jumps become more prominent and frequent, oscillating between \(+150\) m/s\({}^{2}\) and \(-100\) m/s\({}^{2}\). This signifies that the vehicle is traversing a more rugged section of roadway where the wheels are continually striking bigger stones or deeper crevices between them. The vibrations intensify, increasing stress on the vehicle's unsprung mass and suspension system. This segment of the length reveals that the car endures consistent but irregular impacts. Between 0.7 and 0.8 s, there is a pronounced rise in acceleration exceeding \(+300\) m/s\({}^{2}\), subsequently followed by a swift decline to \(-100\) m/s\({}^{2}\). This may suggest that the wheels have encountered a substantial rock or bump, resulting in a significant shock to the vehicle's suspension and its sprung mass. Such leaps may pose significant risks to a vehicle, since they impose substantial pressures on both the wheels and the chassis, with Figure 6 illustrating their abruptness and severity. At 0.85 s, the acceleration changes begin to stabilize, and by 0.9 s, the line approaches linearity, signifying a reduction in vibrations or the conclusion of the vehicle's traversal over the stone pavement. This may indicate that the car moves onto a smoother terrain or decelerates, therefore reducing vibrations. Belgian cobblestone pavement has huge stones with pronounced interstices, resulting in significant and irregular effects on the vehicle's unsprung mass.