# Problems and Design of a Powered Mechanism-Based Car Child Restraint System
## 2 Materials and Methods
### Existing Solutions on the Market and Integrated CRS Devices  
We present research on the trend of integrated devices in vehicle seats, as well as research in patents, articles, design journals, and theses. The devices demonstrate the research interest in integrating mechanisms into vehicle seats. The primary motivation for these devices is safety. The integrated mechanisms offer correct movement and different configurations that adapt to the position of the user. In the market, there are different types of CRSs and accessories, and they are selected according to the height and weight of the child, not according to the age--this is a reference only.  
Currently, a wide variety of conventional SRIs on the market exist that can be chosen for infant use. European Regulation 129 [14], which entered legal effect in 2024, favors the use of a CRS according to the child's body growth and improves the fit of the seat belt; the correct fit of the child depends mainly on height, weight, and, as a reference age, as shown in Table 1. The different characteristics and existing groups of CRSs are explained.  
The existing solutions are summarized, the operation of the device is presented, and representative images are shown. Schemes and kinematics diagrams are made to understand the proposed mechanisms and the movement.  
The present invention is a child restraint system, as shown in Figure 1, including a sensor and an actuator. The control circuit is configured to control the actuator based on input from the crash sensor system. The actuator may activate a safety feature of the CRSwithin a reaction time window of the crash sensor system. The actuator activates the safety function of the CRS within a reaction time interval of the crash sensor system. The actuator includes a pyrotechnic initiator of two types: a leveling actuator or a tension actuator. For example, the actuator is an inflatable airbag or a deployable piston [15].  
The present invention relates to a foldable or integral child seat that has a mechanism that interconnects a backrest link, a headrest link, and a seat link to cause coordinated movement between the links, as per Figure 2 [16].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Groups** & **Technical Data** & **Characteristics of Market-Available Devices** \\ \hline \multirow{4}{*}{Group 0} & Size: 40–65 cm & Carrycot \\  & Weight: 4–10 kg & Backward orientation \\  & Age: 9 mth & 3- or 5-point safety harnesses \\  & Size: 60–85 cm & Chair \\ Group 0+ & Weight: 9–13 kg & Backward orientation \\  & Age: 6–18 mth & 3- or 5-point safety harnesses \\  & Size: 75–105 cm & Chair \\ Group I & Weight: 9–18 kg & Backward orientation and rearward facing \\  & Age: 1–4 yr & 3- or 5-point safety harnesses \\  & Size: 100–125 cm & Chair \\ Group II & Weight: 15–25 kg & Rearward facing \\  & Age: 3–6 yr & 3-point safety harnesses \\  & Size: 75–135 cm & Lift chair/booster cushion \\ Group III & Weight: 22–36 kg & Rearward facing \\  & Age: 6–12 yr & 3-point safety harnesses \\  & Size: 135–150 cm & Booster cushion \\ Booster & Weight: 36–50 kg & Rearward facing \\  & Age: 12–13 yr & 3-point safety harnesses \\ \hline \hline \end{tabular}
\end{table}
Table 1: Description of the CRS groups and characteristics existing on the market.  
Figure 1: The patent entitled child restraint system: (**a**) patent scheme; (**b**) kinematic diagram of a central sliding crank-type mechanism (A and B are reference points).  
Figure 2: The patent entitled child restraint seat: (**a**) patent scheme; (**b**) kinematic diagram of a central and guide sliding crank-type mechanism (A, B and C are reference points).  
The invention provides a type of CRS with automation equipment. The automatic feedback from the automation equipment provides seat angle adjustment and control, seat belt locking and tensioning, and confirmation of correct installation, as per Figure 3 [17].