Analysis of Vibration Comfort and Vibration Energy Distribution in the Child Restraint System-Base Configuration

This study presents the results of an experimental evaluation of ride comfort for children transported in child restraint systems (CRS) during passages over speed bumps, with particular emphasis on the energy contained in vibrations. The tests were carried out under real operating conditions using two vehicles with different suspension characteristics and three loading levels corresponding to different stages of child development. Vertical accelerations were recorded at key points of the vehicle–seat system and subsequently analyzed in accordance with ISO 2631-1. Based on the vibration signals, root mean square acceleration (RMS), vibration dose value (VDV), seat effective amplitude transmissibility (SEAT), and root mean quad (RMQ) indices were calculated, enabling not only the assessment of discomfort levels but also the estimation of mechanical energy transmitted through the seat structure. The results showed that, depending on the type of vehicle, bump geometry, and load mass, the vibration energy can be significant and, in many cases, corresponds to levels classified as “severe” or “extreme discomfort.” At the same time, this energy constitutes a potential power source for low-power sensors in “smart seat” systems, such as those monitoring the child’s posture or environmental conditions. The findings highlight the need to consider vibration comfort criteria and the potential for vibration energy harvesting in the design and homologation of CRS, which aligns with the concept of sustainable transport and the development of energy self-sufficient technologies.