Enhancing Occupant Safety by Pre-active Seat Control for Out-of-seat Position before Autonomous Emergency Braking Operation

The pre-active safety seat (PSS) is a recently developed active safety system for securing occupant safety in out-of-seat position (OOSP), which was applied in the Hyundai Genesis G80 in 2020. However, there has not been sufficient quantifiable verification supporting the effectiveness of the PSS. The present study was performed to determine the effectiveness of the PSS for occupant safety in OOSP and to identify areas for additional improvement. Six test conditions were considered to determine the effectiveness of the PSS for augmentation of occupant safety in OOSP. Ten healthy men participated in the tests. Compared with the no PSS condition, maximum head excursion and neck rotation were significantly decreased in the PSS condition by 0.31–0.79-fold and 0.33–0.48-fold, respectively (p < 0.05). The PSS condition in which the seat pan was moved forward to the mid position showed a greater effect in reducing the characteristic motions related to submarining, compared with the condition in which the seat pan was moved rearward to the mid position (p < 0.05). These results suggested that PSS augments occupant safety in OOSP. This study provides valuable insights in ameliorating risks to the occupant in unintended seat positions before braking and/or collision.

Numerical Analysis of the Unsteady Loads on a Steam Turbine Double Seat Control Valve

The continuously growing request for high operational flexibility also for large scale steam turbine creates new challenges for control valve design. Such components, subjected to large static loads, may also experience strong vibrations due to unsteady turbulent fluctuations downstream the throttling section, which need to be confined sufficiently far from structural natural frequencies in the entire range of operating conditions. This work is focused on a computational analysis of the unsteady steam flow developing within a realistic double-seat control valve employed in industrial steam turbine. Actual operating conditions are considered both in terms of steam inflow pressure and temperature, flow rates and plug height. Three plug heights were considered: two corresponding to almost closed plug thus subjected to choked flow, and the third verified at 4 different steam rates. In order to capture the unsteady nature of the flow and verify the fluid-dynamic forcing frequency, the Scale Adaptive Simulation principle, as implemented in Ansys® CFX 14.5 code, has been employed. Computations were run with a computational time step of 10−4 s and an effective simulation window of 0.2 s for time averaged values and pressure time signals. The unsteady response is monitored analyzing the frequency spectra of both integral variables (i.e. forces and moment on plug) and punctual pressure oscillations. Analysis of results showed that it is possible to correlate the principal frequency and amplitude with the operating conditions. Strouhal number based on plug diameter and bulk flow velocity remains in fact constant independently on operating conditions.

Development of a New Type 4D Dynamic Seat Platform Control System Based on PLC

This article has introduced the development method of a kind of 4d cinema dynamic seat control system based on PLC, expounds the system's hardware structure , working principle, function characteristics, etc. The system's power is provided by hydraulic pump, hardware adopts closed loop feedback control system constituted by omron PLC, A/D module, D/A module, linear displacement sensor and electromagnetic proportional directional valve. The system has good stability, high cost performance, miniaturization, intelligent, etc.