• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.102-111
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• 2010

This paper presents a design of seat mechanism for multi-postures controllable wheelchair. The possible seat postures are reclining, tilting, standing, which are controlled by four seat mechanisms using four linear actuators. The seat mechanisms designed in this study are reclining, tilting, forward-tilting, and elevation mechanism. Three postures except standing are controlled by corresponding mechanisms, but the standing posture is performed by combination of the reclining and the forward-tilting mechanism. Posture control system is composed of PID controllers and a planner to determine a feasible posture based on a posture transition diagram. Simulation results show that the seat mechanism and its control system are applicable to a multi-postures controllable wheelchair.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.5
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• pp.67-75
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• 2011

A new energy absorbing mechanism for car seat was developed to reduce the neck injury in rear impacts. Energy absorbing principle is based on the shear-bolt behavior of thin-walled cast components subjected to static and dynamic loads. Results of shear bolt test using AM60 of Mg alloys showed robust behavior giving an approximately constant mean force during failure processes. Simply designed energy absorbing mechanism was assembled with the recliner between seat backs and seat rails. We have simulated the sled test of seat with dummy under the rear end impact using the finite element method. Results of simulation show that the new seat mechanism reduces thorax acceleration to a considerable extent, but it is not sufficient to mitigate neck injury indices e.g. neck shear force, neck tension force and NIC. With heightened headrest and narrowed backset, the energy absorbing mechanism resulted in good performance of protecting the neck injuries.

• Journal of Drive and Control
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• v.13 no.4
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• pp.1-6
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• 2016

Typically, the seat of an automotive vehicle generally includes a horizontal seat-cushion portion and a vertical seat-back portion that is operatively connected to the seat-cushion portion. The seat may include a recliner for the reclining of the seat-back portion relative to the seat-cushion portion by the seat occupant. An energy absorber or damper can also be provided for the seat-back portion. Because the recliner is configured to be released at a relatively high speed, and it results in an impact at the end of a folding stroke, the damper needs to dissipate energy as the seat back moves with respect to the seat cushion; therefore, the role of the seat damper in the automotive-seat design is important. In this paper, the mechanism of an hydraulic-type automotive-seat damper is investigated, and the torque characteristic is simulated according to the design-parameter variations such as the orifice area and the working-fluid properties.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.205-212
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• 2003

This paper may provide a basic design data for the safer car seat mechanism and the quality of the material used by finding out the passenger's dynamic behavior when protected by seat belt during collision. A computer simulation with finite element method is used to accomplish this objective. At first, a detailed geometric model of the seat is constructed using CAD program. The formation of a finite element from a geometric data of the seat is carried out using Hyper-Mesh that is the commercial software for mesh generation and post processing. In addition to seat modeling, the finite element model of seat belt and dummy is formed using the same software. Rear impact analysis is accomplished using Pam-Crash with crash pulse. The part of the recliner and right frame is under big stress in rear crash analysis because the acceleration force is exerted on the back of the seat by dummy. The stress condition of the part of the bracket is checked as well because it is considered as an important variable on the seat design. Front impact model which including dummy and seal belt is analyzed. A Part of anchor buckle of seat frame has high stress distribution because of retraction force due to forward motion of dummy at the moment of collision. On the basis of the analysis result, remodeling and reanalysis works had been repeatedly done until a satisfactory result is obtained.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.945-946
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1171-1172
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.249-250
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• 2008

• 한국기계연구소 소보
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• s.11
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• pp.29-38
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• 1984

• Journal of Industrial Technology
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• v.26 no.A
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• pp.47-54
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• 2006

To improve passenger safety, seat belt systems with pre-tensioner that tightens seat belt webbing using explosive just before collision are widely used these days. Even though seatbelt must not unlatched without passengers' operation. explosive power of pre-tensioner can cause unlocking of a buckle. To prevent the unlocking, an anti-g mass that blocks displacement of the release button has been attached to the buckle. In this study, the dynamics and statics of locking mechanism associated with operation of anti-g buckle has been theoretically investigated, and important design variables that affect the operation of anti-g buckle have been identified. Through the total seat belt system's dynamic simulation using force and displacement inputs obtained from seat belt sled test, design of the proposed anti-g buckle has been validated.

• Korean Management Science Review
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• v.30 no.1
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• pp.1-14
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• 2013

We conduct the future studies suggested by Park and Seo [3]. They considered a seat inventory control problem in which flights depart sequentially during a similar time-interval and passengers purchase available seats depending on individual customer choice behavior. Customer choice behavior can lead to one among a horizontal shift, a diversion-up, and a booking loss when a desired fare class is unavailable. We investigate how seat availability calculation method, booking limit control mechanism, seat inventory capacity, number of booking class, type of seat demand influence on revenues in an airline industry through thorough computer simulation experiments.