• Proceedings of the KSME Conference
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• 2001.06a
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• pp.806-811
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• 2001

To develop design and evaluation technologies of automotive seat frames, structural analysis and fatigue tests have been performed. Under the back moment loading condition, the numerical simulation yielded the maximum stress over the yield strength at the side frame bracket. To measure the stresses under the test condition, strain gauges were attached on some weakest points of the side frames. the measured strains are in good agreements with the CAE results. On the other hand, fatigue tests have been performed using the side frame bracket specimens made of various welding types to estimate their durabilities. From the fatigue test results and the analysis ones, it was recommended that the welding position of the bracket should be moved upward.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.50-57
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• 2004

Structural analysis and fatigue tests have been performed to develop design and evaluation technologies of automotive seat frames. Under the back moment loading condition, the numerical simulation unveiled the maximum stress up to the yield strength at the side frame bracket. To measure the stresses under the test condition, strain gauges were attached to some weakest points of the side frames. the measured strains are in good agreements with the CAE results. On the other hand, some fatigue tests have been performed using the side frame bracket specimens made of various welding types to evaluate their durabilities. From the fatigue tests and the numerical analyses, it was recommended that the bracket welding position should be moved upward.

• Journal of IKEEE
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• v.26 no.4
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• pp.602-613
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• 2022

This paper proposes an algorithm for correcting indirect situations resulting from the wheelchair moving the stairs with wheel-type caterpillar and seat position variable. For analyzing the Yawing movement model, the change of Yaw value was estimated using Roll, Pitch, and Yaw in the driving environment, and it was used as a control variable and the information of the wheel drive controller. The verification confirmed the correction of about 10° of Yawing movement within about 7 seconds. It was confirmed that the angular velocity was reduced by 47.5% in seat position change.

• International Journal of Automotive Technology
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• v.7 no.7
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• pp.827-832
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• 2006

Occupant classification and position detection have been significant research areas in intelligent safety systems in the automotive field. The detection and classification of seat occupancy open up new ways to control the safety system. This paper deals with a novel algorithm development, hardware implementation and testing of a prototype intelligent safety system for occupant classification and position detection for in-vehicle environment. Borland C++ program is used to develop the novel algorithm interface between the sensor and data acquisition system. MEMS strain gauge hermatic pressure sensor containing micromachined integrated circuits is installed inside the passenger seat. The analog output of the sensor is connected with a connector to a PCI-9111 DG data acquisition card for occupancy detection, classification and position detection. The algorithm greatly improves the detection of whether an occupant is present or absent, and the classification of either adult, child or non-human object is determined from weights using the sensor. A simple computation algorithm provides the determination of the occupant's appropriate position using centroidal calculation. A real time operation is achieved with the system. The experimental results demonstrate that the performance of the implemented prototype is robust for occupant classification and position detection. This research may be applied in intelligent airbag design for efficient deployment.

• Physical Therapy Korea
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• v.14 no.3
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• pp.90-96
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• 2007

The purpose of this study was to compare the joint position sense at the knee joint at 3 different surface conditions by using the active knee joint angle reproduction test in the standing position. Twenty healthy volunteers (10 males and 10 females) age 20~29 years were recruited for this study. The knee joint position senses were assessed at three different surface conditions: on the floor (stable condition), TOGU (soft condition), and seat fit (unstable condition) in a closed kinetic chain. Testing orders were selected randomly. The absolute angle error was defined as the absolute difference between target angles ($30^{\circ}{\sim}45^{\circ}$ knee flexion) and subject perceived angle of the knee flexion. One way ANOVA was used to compare the absolute angle of error among 3 different conditions. The Independent t-test was used to compare the absolute angle of error between male and female. The error angles were significantly different among surface conditions ($1.3^{\circ}{\pm}1.2^{\circ}$ for the floor, $2.1^{\circ}{\pm}0.9^{\circ}$ for the TOGU, and $4.4^{\circ}{\pm}1.8^{\circ}$ for the seat fit, p<.05). There was no significant difference in error angle between male and female. In conclusion, the joint position sense of the knee joint in the closed kinetic chain decreased at unstable surface conditions. The result of this study indicates that surface conditions should be considered when assessing and training the joint position sense of the knee joint in clinical setting.

• Journal of Biosystems Engineering
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• v.34 no.5
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• pp.305-314
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• 2009

The purpose of this paper was to design an effective control system of 1-axis exciter for a seat vibration test of agricultural tractors using MATLAB simulation. The developed simulation model was composed with a hydraulic pump, a hydraulic servo valve, a hydraulic cylinder and load system. Also it was verified by comparing the simulation results with experimental results of actual control system in order to optimize the control performance. And in order to improve its control performance, the designed PID controller in this research was tuned using Ziegler-Nichols 2nd law and zero's moving method of PID controller's transfer function. As the result of these research, the developed position control system was able to control the system's position accurately within 5% errors.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.101-107
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• 2018

In this study, the analysis of radiation noise and chattering noise of vehicle seat recliner was conducted through testing and analysis. First, operating noise was measured by seat back frame and recliner, and chattering noise was confirmed. Next, the transient dynamic analysis was performed, and the result was mapped to the acoustic analysis. Finally, the test and analysis were compared and analyzed. The results are as follow. First, it was found that the peaks appeared in common in the range of 620~650Hz, 1,240~1,290 Hz, and 1,840~1,940 Hz. It was judged that the dynamic characteristics of the recliner system overlapped with the rotation component of the motor to cause amplification of noise and vibration. Next, as a result of imaging the radiation noise analysis, it was judged that the noise radiated in the forward and backward direction has a greater influence than the direction of the rotation axis when the ear position of the person is taken as a reference.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.15-20
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• 2017

This study analyzed the load change of the gear generated by the operation of the vehicle recliner through Finite Element Analysis. The basic model of the recliner used was a commercial product, and the effect of the seat frame was excluded. The load conditions applied to the recliner were set considering gravity, the mass of the seat's back frame, and the weight of a person. The operating mode was set to move the seat back from the vertical to the reclined position. As a result, it was found that the tooth bending amount of the gear rim and wheel increased from the cam rotation angle of 450 degrees, and a change in the contact ratio occurred. Furthermore, excessive torque fluctuations occurred in the ranges of 390 to 450 and 750 to 710 degrees. It was found that this occurred in the region of about 30 degrees before and after the point where the x-axis direction load is larger than the y-direction load. From this torque fluctuation it was determined to likely to cause chattering noise.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.459-464
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• 2024

The purpose of this study is to design a toilet lifting seat to prevent falls accidents in the elderly while using the toilet. Prior to design, laws and national standards related to restroom use were investigated and the available space for the assistive devices to be installed was determined. In additions, considering the body size and operating range of the elderly, the optimal final position of the toilet seat is set so that users can use it more safely and conveniently without external help. Moreover, in order to provide an effective standing assistance function, a complex 4-bar link structure was applied to enable simultaneous seat elevation and angle adjustment when operating the device, and the appropriate link shape and dimensions were determined using a linkage program and UG NX. FEA analysis using ANSYS Workbench is performed to ensure the robustness of the stretched linkage and the feasibility of the lifting seat is verified through fabrication.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.104-113
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• 2013

New USNCAP has been carried out by NHTSA including front and side crash from MY2011. In this paper, test results for USNCAP Side crash were reviewed by statistical analysis. This review focused on side crash test results to investigate the effect of changes from new USNCAP side crash test protocol among 30 passenger cars. These results were summarized as followings. Total number of 5 star vehicles on the front seat dummy (16 vehicles, 53.3%) was slightly smaller than the rear seat's (17 vehicles, 56.7%) in MDB test. For the ES-2re dummy, chest injury, ie maximum rib deflection contributed to 66% in the mean value of $P_{joint}$. Pelvis injury was highly dependent upon performance up to 87% in the SID-IIs dummy cited on the rear seat in average $P_{joint}$. For Pole test, pelvis injury made contribution to the average performance to 83%. For standard deviation, it showed the largest value in the same body region as the mean value for each dummy. Overall front seat performance showed 14 vehicles, 44.6% with 5 star vehicles less than each MDB or Pole test result. This result showed that performances in MDB test were different pattern to Pole test on driver position. Number of 5star vehicles for overall side NCAP performance are 18 passenger cars (60%). Curtain airbag and driver thorax airbag were equipped in all test vehicles. One vehicle is equipped with thorax airbag in the rear seat. Results from two side tests considered as reliability problem, ie the cause for large standard deviation in side crash test. Consequently, the countermeasure for new USNCAP side crash test is essential to design the effective side structures for side collision and to control well dummy kinematics with curtain and thorax airbag in order to reduce chest and pelvis injuries.