• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.832-835
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• 2003

This paper presents a design and characteristics analysis of a SRM drive for EPS(Electrically Power Steering) application. A conventional driving room space and mechanical structure are suggested in design stage. In the restricted design conditions, motor parameters are determined for sufficient torque and speed. For the smooth torque generation and simple circuit of power system, 12/8 motor drive is considered. With FEM and magnetic circuit analysis, designed motor is simulated to meet the requirement of specifications. Effectiveness of the suggested SRM drive for EPS application is verified by the manufactured prototype motor drive tests.

• 한국정밀공학회지
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• 제27권12호
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• pp.75-83
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• 2010

Every mechanical part for mass production has dimensions with tolerances in engineering drawing. Tolerance is given to guarantee assemble parts together satisfying functional requirements and dimensional constraints. Tolerance is essential factor for standardization of parts or assembly and has huge influence on manufacturing cost. It will be desirable to have tolerances as broad as possible for minimizing manufacturing cost. This paper describes tolerance analysis of u-joint assembly that is a part of automobile steering system. Within the range of tolerances of parts, accumulated effect is estimated by arithmetic calculation, probability theory and Monte carlo simulation. Each result is compared to investigate the method for increasing productivity.

• International Journal of Precision Engineering and Manufacturing
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• 제5권1호
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• pp.5-12
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• 2004

A human-friendly interactive system that is based on the harmonious symbiotic coexistence of human and robots is explored. Based on this interactive technology paradigm, a robotic cane is proposed for blind or visually impaired travelers to navigate safely and quickly through obstacles and other hazards faced by blind pedestrians. The proposed robotic cane, "RoJi,” consists of a long handle with a button-operated interface and a sensor head unit that is attached at the distal end of the handle. A series of sensors, mounted on the sensor head unit, detect obstacles and steer the device around them. The user feels the steering command as a very noticeable physical force through the handle and is able to follow the path of the robotic cane easily and without any conscious effort. The issues discussed include methodologies for human-robot interactions, design issues of an interactive robotic cane, and hardware requirements for efficient human-robot interactions.ions.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.51-60
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• 2013

In this paper, to control the existing headlamp control system using steering wheel angle more efficiently and more actively, image processing algorithm which improved the detection rate of lane at night based on camera was suggested. And to recognize road lane more clearly in the conditions of low illumination, new algorithms were developed in the aspects of improving brightness, extracting clear lane edge and using the characteristics of lane. Through this research, it turned out that lane detection ability by using the normalized stretching, angular mask and expected-area scan have good performance in the night compare to existing algorithms.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.394-399
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• 2004

In order to secure the safety of power steering system, it is necessary to perform the strength and the fatigue analysis of pulley in this paper. The applied stress distribution of the pulley subject to combined loads condition was obtained using finite element analysis. Based on these results, the fatigue life of the pulley with the variation of the fatigue strength was evaluated using durability analysis simulator. The optimal hole size to improved the safety of the pulley was investigated using parametric study. Moreover, the predicted fatigue life cycle with the simulator was verified by experimental tests.

• 한국기계가공학회지
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• 제20권12호
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• pp.107-112
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• 2021

The usage of electric-powered components consisting of several electrical and mechanical parts is continuously increasing in automobiles. Therefore, continuous assessment of the reliability and quality of these electric-powered parts is crucial. In this study, a noise and vibration measurement system for testing and evaluating the different electric-powered parts of automobiles was designed. Further, an FFT analysis was performed on some electric-powered steering assembly test equipment. In the FFT analysis of the noise and vibration signals for each essential fault part, the vibration FFT analysis was significantly compared with the noise analysis. The results showed that the vibration FFT analysis was more effective in determining the reliability and quality of the electric-powered parts.

• 소성∙가공
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• 제21권7호
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• pp.397-402
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• 2012

The flange hub is a main component in an automotive steering system. In general, the flange hub are fabricated by mechanical machining, which is a process where material waste is inevitable. It is well-known that a net-shape cold forging cannot only reduce material waste but can also improve the mechanical strength of the final product. Thus, a forging process design was conducted for production of a flange hub. Significant spring-back occurs around the flange due to its small thickness in conjunction with the residual stresses after forging. In order to achieve the required dimensional accuracy, a process design with appropriate spring-back control is needed. In this study, a modification of the forging die was designed based on FE analysis with the purpose of spring-back compensation. Four kinds of different die designs were evaluated and the optimum design has two times less spring-back than the initial design. The compensation angle of the optimum design is 0.5 degrees. The results have been experimentally confirmed by cold forging of a flange hub and comparing the amount of spring-back between the actual component and the FE analysis.

• 대한기계학회논문집A
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• 제24권1호
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• pp.118-123
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• 2000

Most quadruped walking robots under current research are individually controlling every joint ic make them step or walk according to an integrated strategy. Such methods are characterized by at least one pair of an actuator and a sensor installed per each 'oint so that the robots weigh execssively and move inefficiently in terms of energy expenditure. In addition, the task of controlling all the joints simultaneously is quite complex and prone to destabilize the robot motion. These respects keep the existing walking robots away from realistic applications such as transportation even if they have potentially, outstanding adaptability to swamps or uneven terrains as opposed to wheeled vehicles. So, this paper presents a new conceptual quadruped robot developed to walk and steer only with a minimal number of actuators owing to a closed-chain mechanism. To prove its actual performance including the adaptability to various types of terrains. experiments are done with the mammal-type prototype. And. it is also shown that the same concept can be easily extended to carry out different gait forms. for instance, that of spiders only with minor modifications.

• 대한기계학회논문집A
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• 제20권11호
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• pp.3525-3537
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• 1996

This paper presents a CAD program develpoed on a microcomputer in order to support graphic and computational assessment of ergonomic problems associated with the design of a man-in-cab system. The program is coded to help workspace designers with ergonomic evaluations needed in the design stage. This paper proposed a biomechanical -ergonomic evaluations needed using man and workplace models. The human model is developed to have dimensions obtained from the Korean anthropometric data reported in 1992. Its graphical representation is based on a wire-frame model but, whenever necessary, body segments can be represented by a solid model with hidden line/faces removed and shaded. Workplace models are presented for cabs of the excavator, one of the most popular construction vehicles. A workplace model consists of an operator seat, a steering wheel. two control levers, two pedals, and a control panel. The workplace elements can be modified in their sizes, positions, and orientations by changing the reference point and design parameters. An algorithm for the view test is suggested and loaded to provide a visual evaluaiton of the overall layout of a workplace model.

• 대한기계학회논문집A
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• 제23권11호
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• pp.1960-1969
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• 1999

This paper presents dynamic modeling and controller design of a tracked vehicle installed with the double rod type ERSU(electro-rheological suspension unit). A 16 degree-of-freedom model for the tracked vehicle is established by Lagrangian method followed by the formulation of a new sky-ground hook controller. This controller takes account for both the ride quality and the steering stability. The weighting parameter between the two performance requirements is adopted to adjust required performance characteristics with respect to the operation conditions such as road excitation. The parameter is appropriately determined by employing a fuzzy algorithm associated with the vehicle motion. Computer simulations are undertaken in order to demonstrate the effectiveness of the proposed control system. Acceleration values at the driver's seat are analyzed under bump road profile, while frequency responses of vertical acceleration are investigated under random road excitation.