• 전자공학회논문지
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• 제50권1호
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• pp.276-284
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• 2013

본 논문에서는 관성항법시스템의 전달정렬시 속도정합 알고리듬에 대하여 지렛대 거리 오차의 가관측성 분석을 수행하였다. 이를 위해 지렛대 거리 오차를 포함한 칼만필터 상태 변수를 모델링하였고 측정 방정식을 구성하였다. 가관측성 분석 방법으로는 SOM을 이용하였고 다양한 항체의 운항 조건들에 대하여 가관측성 분석을 수행하였다. 기존의 지렛대 거리 오차를 포함한 가관측성 분석 기법들은 시뮬레이션을 통한 분석이 주를 이룬 반면에 본 논문에서는 상태 변수들이 완전 가관측하기 위한 항체의 운항 조건을 해석적으로 제시하였다. 그리고 시뮬레이션을 수행하여 분석 결과를 검증하였다.

• 한국기계가공학회지
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• 제7권2호
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• pp.60-65
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• 2008

The high-technology industries including a semi-conductor and an information communication need an ultra-precision technology from the technological points of view. Nano technology based on an ultra-precision technology is being studied to overcome the delicate technology that may occur in the semi-conductor fields. Then, the transferring equipment with high resolution and long displacement becomes an important technology. The goal of this study is to analyze the displacement magnification mechanism driven by piezoelectric actuator which has high resolution and fast response characteristics using flexure hinge with the merits of soft displacement, negligible back-lash and stick-slip, and no-lubrication. The analyses to reduce the magnification losses occurred during the magnification process are performed using ANSYS software based on FEM. The five design variables such as arm thickness, thickness of hinge, radius of hinge, length of input side at the 1st lever and magnification ratio of 1st lever are optimized to induce the maximum magnification ratio using Taguchi method.

• 한국기계가공학회지
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• 제19권2호
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• pp.81-88
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• 2020

The damping hinge of a built-in refrigerator was examined in terms of its stress and fatigue life. Analysis of the initial design showed that stress concentration occurred at the concave surface of the hinge lever, which was broken during the door opening-and-closing endurance test of the prototype. The maximum von Mises stress at this location exceeded the yield strength. In addition, Goodman fatigue analysis of the initial design showed that the fatigue life at this location was consistent with the failure observed during the endurance test. Based on these results, an improved design for the damping hinge was derived. Analysis of this improved design showed that the stress concentration in the hinge lever of the initial design was eliminated. In this case, the maximum stress occurred at the position where the hinge lever was in contact with the door stopping pin, and the maximum von Mises stress was smaller than the yield strength. Goodman fatigue analysis of the improved design indicated that the fatigue life of the entire damping hinge was infinite. It was therefore concluded that the improved design does not suffer from fatigue damage during the endurance test.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.41-46
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• 2007

This article deals with the design and prototyping of Shift-By-Wire system for an automatic transmission equipped vehicle. In order to manipulate the shifting action electronically, Shift-By-Wire system consists of an electronic shift lever, an electric shift actuator and position sensors. The shift lever is designed to transform the driver's shifting command into an electric signal; it includes the position sensor using non-contact type hall sensor and an additional shifting switch acting as Tip-tronic. For the design of an electric shifting actuator, we investigated the stroke angles and shifting efforts of the manual control lever in each shifting section. And the position sensor of the shifting actuator is designed by using a potentiometer with an optical encoder. Finally the prototype of Shift-By-Wire system was built in a conventional 2.4L class SUV vehicle, and we performed road tests in order to verify its performance.

• The Journal of Korean Physical Therapy
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• 제16권3호
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• pp.205-216
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• 2004

The purpose of this study is to find application of combination of insotonic(CI) in clinical approach. This is a literature study with books and clinical experience. CI was developed after Margaret Knott that is very useful in clinically. CI has two lever system. It has class II lever system for eccentric contraction and class III lever system for concentric contraction. Therefore it make two different contraction that is not only magnitude of motion and speed increase of motion but also biomechanical advantage. Application of CI has much variety by patient position and treatment position. Especially, it is very effectable on mat activities and training for mid stance period. CI apply in supine position on treatment table, mat or high mat activities, bridging activities, all fourth activities and sit on chair activities. CI apply serially with different techniques. These are rhythmic initiation, dynamic reversal, approximation, rhythmic stabilization and replication.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1253-1267
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• 2005

Misalignment can be an important problem in the integration of GPS/INS. Observability analysis of the alignment errors in the integration of low-grade inertial sensors and multi-antenna GPS is presented in this paper. A control-theoretic approach is adopted to study the observability of time-varying error dynamics models. The relationship between vehicle motions and the observability of the errors in the lever arm and relative attitude between GPS antenna array and IMU is given. It is shown that alignment errors can be made observable through maneuvering. The change of acceleration makes the components of the relative attitude error that are orthogonal to the direction of the acceleration change observable. The change of angular velocity makes the components of the lever arm error that are orthogonal to the direction of the angular velocity observable. The motion of constant angular velocity has no influence on the estimation of the lever arm.

• Journal of Positioning, Navigation, and Timing
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• 제11권3호
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• pp.199-208
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• 2022

Inertial Navigation System (INS)/Global Navigation Satellite System (GNSS) integrated navigation system can be used for land vehicle navigation. When the GNSS signal is blocked in a dense urban area or tunnel, however, the problem of increasing the error over time is unavoidable because navigation must be performed only with the INS. In this paper, Non-Holonomic Constraints (NHC) information is utilized to solve this problem. The NHC may correct some of the errors of the INS. However, it should be noted that NHC information is not applicable to all areas within the vehicle. In other words, the lever arm effect occurs according to the distance between the Inertial Measurement Unit (IMU) mounting position and the NHC effective point, which causes the NHC condition not to be satisfied at the IMU mounting position. In this paper, an INS/GNSS/NHC integrated navigation filter is designed, and this filter has a function to compensate for the lever arm effect. Therefore, NHC information can be safely used regardless of the vehicle's driving environment. The performance of the proposed technology is verified through Monte-Carlo simulation, and the performance is confirmed through experimental test.

• 가정과삶의질연구
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• 제25권2호
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• pp.1-12
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• 2007

This is an investigative study to consider children's COA by parent's problem drinking and their psychological-social character by the COA. According to the results of this study, almost half of the children's COA, among those who have problem drinking parents, demonstrated high dangerous lever in the lower factors, such as emotional character, personnel relative character, and co-dependent character. Results of the inspection into the differences between the psyrhological-social characters, according to the danger lever of the children's COA, suggested the children's danger lever is higher, the self-efficiency and adaptable flexibility, which are the psychological-social characters, are lower, and there are no special differences in the social-support.

• International Journal of Control, Automation, and Systems
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• 제4권2호
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• pp.247-254
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• 2006

For more accurate navigation, lever arm compensation is considered. The compensation method for GPS and an odometer is introduced and new compensation methods are proposed for an odometer to consider the effect of coordinate transformation errors and the scale factor error. The methods are applied to a GPS/INS/odometer integrated system and the simulation and experimental results show its effectiveness.

• 센서학회지
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• 제29권5호
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• pp.336-341
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• 2020

The deflection and null balance methods are used for precision force measurement in the precision industry. Since both methods are based on deformation, the performance of the load cell mechanism is important. In this study, the design variables were obtained via the free body diagram of a lever-linked Roberval mechanism (combined with a flexible hinge link and a Roberval mechanism), and the design characteristics were analyzed according to the weight method. Based on the design characteristics, the optimal design was conducted according to the weight method and FEM was used to verify its reliability.