• Journal of the Ergonomics Society of Korea
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• v.25 no.4
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• pp.115-119
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• 2006

To investigate the effects of independent suspension technology(IST) of hiking boot on the stability and load of foot, eight participants performed medial and lateral drop landing from 33.4cm height and 85cm distance to uneven surface while wearing normal & IST hiking boots. For the stability of foot during the drop landing, the balance angle & suspension angle and rearfoot angle was analyzed using high-speed video analysis. Also kinetic analysis using the force plate and insole pressure measurement was conducted to analyze vertical & breaking ground reaction force and pressure distribution. Not only the balance angle & suspension angle but also rearfoot angle was improved with IST boots for lateral drop landing. These results indicate the IST boots may have the suspension function which keeps the foot to be stable during landing. However the IST boots did not show any effect for medial landing. This might be related to the hardness of medial part of outsole. Therefore the softer outsole of medial part could be recommended. Furthermore the impact force & breaking force and insole pressure were reduced with IST boot. These results means that IST boot has not only cushioning effect but also good grip effect. Therefore the hiking boots applied the independent suspension function may help to reduce fatigue and prevent injury such as ankle sprain in hiking on uneven surface.

• Transactions of Materials Processing
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• v.32 no.6
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• pp.352-359
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• 2023

Recently, independent suspension systems have been applied not only to passenger cars but also to large commercial vehicles. Therefore, the need for research to domestically produce such independent suspensions for large commercial vehicles is gradually increasing. In this paper, we conducted research on the manufacturing technology of the relay lever, which are integral components of independent suspension systems for large commercial vehicles. Our goal was to reduce the flash volume generated during the forging process. The shape variables of the initial billet were adjusted to find proper forming conditions that could minimize flash volume while performing product forming smoothly. Shape variables were set as input variables and the flash volume was set as an output variable, and simulations were carried out to analytically predict the volume of the flash area for each variable condition. Based on the data obtained through numerical simulations, a regression model and an artificial neural network model were used to develop a prediction model that can easily predict the flash volume for variable conditions. For the corresponding prediction model, a goodness of-fit test was performed to confirm a high level of fit. By comparing and analyzing the two prediction models, the high level of fit of the ANN model was confirmed.

• Transactions of Materials Processing
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• v.17 no.7
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• pp.481-485
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• 2008

The subframe type rear suspension consisting of a side member and a front/rear cross member is widely used in a medium car and full car. In the small car case, the beam of tubular type without independent suspension system is used to reduce manufacturing cost. In this study, a subframe type rear suspension by hydroforming has been developed. In designing suspension, a driving stability and durability should be considered as an important factor for the performance improvement, respectively. Thus, we focus on increasing the stiffness of suspension and decreasing the maximum stress affecting a durability cycle life. Several optimization design techniques such as shape, size, and topology optimization are implemented to meet these requirements. The shapes of rear suspension obtained from optimization are formed by using hydroforming process. Through commercial software based on the finite element, the superiority of this design method is demonstrated.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.749-756
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• 2006

This paper presents a complex stochastic wheelbase preview control method of a motorcycle suspension based on hierarchical modeling method. As usual, a vehicle suspension system is controlled as a whole body. In this method, a motorcycle suspension with five Degrees of Freedom(DOF) is dealt with two local independent 2-DOF suspensions according to the hierarchical modeling method. The central dynamic equations that harmonize local relations are deduced. The vertical and pitch accelerations of the suspension center are treated as center control objects, and two local semi-active control forces can be obtained. In example, a real time Linear Quadratic Gaussian(LQG) algorithm is adopted for the front suspension and the combination of the wheelbase preview and LQG control method is designed for the rear suspension. The results of simulation show that the control strategy has less calculating time and is convenient to adopt different control strategies for front and rear suspensions. The method proposed in this paper provides a new way for the vibration control of multi-wheel vehicles.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2210-2220
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• 2009

Independent-suspension type axles for heavy duty special vehicles are usually produced by only a few specialized companies. The special techniques, such as designing, producing, testing techniques has been unveiled. The test of durability with the vehicle in which is installed a prototype taking several years is required for setting the designing parameters. In this research, through-drive the core-component of the independent-suspension type axle has been tested with the reverse engineering and the testing methods for the confirmation of the accomplishment in the development goal has been suggested. Also the prototype is developed from designing and testing the design with the CAD and CAE tools. As a result, the process and testing methods studied in this research are useful in the development of power train.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.11
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• pp.81-88
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• 1999

A conventional quarter-car suspension system is a single input system with one actuator. Thus, the performance enhancement for ride quality could be limited. In this paper, we propose a novel automotive suspension system for a quarter-car with two independent actuators to improve the control performance. The left eigenstructure assignment method for multi-variable systems has been applied to the proposed novel quarter-car model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.205-208
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• 2008

Generally, there are several types in rear suspension. The rear suspension of subframe type consisting of side member and front/rear cross member is widely used in a medium car and full car. In the small car case, the beam of tubular type without independent suspension system is used to reduce manufacturing cost. The optimized rear suspension of subframe type using hydroforming method has been developed in this study. In designing suspension, the driving stability and durability performance should be considered as an important factor. The stability is related to dynamic frequency and durability is connected with stress analysis of structure. We focus on increasing the stiffness of suspension and decreasing the maximum stress relating to durability cycle life. For making use of the merits of hydroforming which is possible to make the bead, tube expansion, and feeding in desiring position, several optimization design techniques such as shape, size, and topology optimization are proposed. This optimization scheme based on the sensitivity can provide distinguished performance improvement in using hydroforming. Through commercial software based on the finite element, the superiority of this design method is demonstrated.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.261.1-261
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• 1995

No Abstract, See Full Text

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.1
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• pp.100-106
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• 2013

This paper describes an integrated optimization design using multilevel decomposition technique on the base of the parametric distribution and independent axiom at the stages of lower level. Based on Pareto optimum solution, the detailed parameters at the lower level can be defined into the independent axiom. The suspension design is used as the simulation example.

• Journal of Power System Engineering
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• v.4 no.2
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• pp.65-70
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• 2000

The shimmy phenomenon, or the radial vibration of steering wheel, happens frequently at a high speed, complicated with suspension system, steering system, vehicle body, engine, transmission and tire. In this study, the suspension system and steering system are modeled by the reference of vehicle body design coordinates(T.L.H), the coordinate system usually used by passenger car maker. In addition, the theoretical results from numerical method have been investigated and compared with the experimental ones by the correlating analysis between the tire and sub-system. The steering and suspension system modeled for the numerical analysis are both independent type. This study developed an analysis program which could forecast the shimmy level in advance by the variation of properties in each system and the change in design of new model.