• Smart Structures and Systems
• /
• 제18권3호
• /
• pp.585-599
• /
• 2016

Steel cables serve as the key structural components in long-span bridges, and the force state of the steel cable is deemed to be one of the most important determinant factors representing the safety condition of bridge structures. The disadvantages of traditional cable force measurement methods have been envisaged and development of an effective alternative is still desired. In the last decade, the vision-based sensing technology has been rapidly developed and broadly applied in the field of structural health monitoring (SHM). With the aid of vision-based multi-point structural displacement measurement method, monitoring of the tensile force of the steel cable can be realized. In this paper, a novel cable force monitoring system integrated with a multi-point pattern matching algorithm is developed. The feasibility and accuracy of the developed vision-based force monitoring system has been validated by conducting the uniaxial tensile tests of steel bars, steel wire ropes, and parallel strand cables on a universal testing machine (UTM) as well as a series of moving loading experiments on a scale arch bridge model. The comparative study of the experimental outcomes indicates that the results obtained by the vision-based system are consistent with those measured by the traditional method for cable force measurement.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.1289-1292
• /
• 2006

The demand on a turnout layed on a bridge is rising owing to the increasing number of stations on the viaduct. And also the demand on a turnout with CWR is rising to upgrade running speed of the passing train. A CWR connected with turnout is subjected to additional axial force induced by the actions due to change in temperature, braking and starting force, and bending of the deck. But magnitude and distribution of the axial force in rails of turnout is not clear yet. So, in this study, a field measurement was conducted to know them. The strain gage method was adopted for field test. The FBG sensor for the strain measurement was used to ensure stability of test value and durability of gage for long term. It is expected that we can get data on the axial force in rail connected with turnout with respect to seasonal temperature change by the established field test system.

• 전기학회논문지
• /
• 제63권10호
• /
• pp.1473-1478
• /
• 2014

This paper deals with design and thrust force measurement of EMS type LSM for propulsion of the high-speed maglev train. The load of maglev train is calculated, and the design equations of the LSM are presented, and the LSM which is suitable for the operation of short-distance test track is designed. In addition, the finite element analysis is performed to confirm the back-EMF and thrust force characteristics of the LSM designed model. A short length LSM prototype model is manufactured. Finally, the thrust force of the LSM is measured by the method applying dc current to the stator winding instead of three-phase ac current. And the validity of the design and analysis is verified by this measurement.

• 대한한의학회지
• /
• 제35권4호
• /
• pp.74-82
• /
• 2014

Objectives: Quantification, objectification, and standardization of lifting-thrusting manipulation are important issues in traditional Chinese medicine (TCM). The purpose of this study was to quantitatively investigate the difference in the amount of stimulation according to range and frequency among parameters of lifting-thrusting manipulation with the use of a needle insertion-measurement system. Methods: For quantification of lifting-thrusting manipulation, an acupuncture needle insertion-measurement system was used in phantom tissue. The motor and force sensors of the needle insertion device were connected to the control software. This enabled operation of the lifting-thrusting manipulation and measurement of the acupuncture needle force. The measurement of the acupuncture needle force according to various frequencies (0.25, 0.50, 0.75, and 1 Hz) and ranges of movement (2, 4, 6, 8, and 10 mm) was repeated 10 times. Results: At a constant frequency of movement, acupuncture needle force according to range of movement (2, 4, 6, 8, and 10 mm) increased with increasing range of movement (p < 0.05). At a constant range of movement, acupuncture needle force according to frequency of movement (0.25, 0.50, 0.75, and 1.0 Hz) increased with increasing frequency of movement (p < 0.05). Conclusion: In this study, we conducted a quantitative comparison of the amount of stimulation according to range and frequency, the main parameters of lifting-thrusting manipulation, by using an acupuncture needle insertion-measurement system. Future studies on various manipulations and parameters are warranted to quantify and objectify the amounts of stimulation by acupuncture manipulation.

• Journal of Acupuncture Research
• /
• 제30권5호
• /
• pp.87-94
• /
• 2013

Objectives : In this study, we intended to make the foundation of the development of acupuncture tissue model as comparing the needle sensation of six kinds of tissue models and Zusanli ($ST_{36}$) with the needle force measurement system. Methods : When practitioners did twisting-rotating acupuncture needle manipulation after inserting the needle into six kinds of tissue models, they quantified the similarity sense to the sensation of Zusanli ($ST_{36}$) with the NRS (Numeric Rating scale). As needle force measurement system did twisting-rotating Acupuncture needle manipulation after inserting needle into Zusanli ($ST_{36}$) of human and six kinds of tissue models, it can calculate the coefficient of viscosity by measuring the torsion friction. We compare the NRS of practitioners' needle sensation to the coefficient of viscosity of needle force measurement systems. Result : As practitioners' NRS assessment to quantify needle sensation, apple and cucumber showed 70% similarity to Zusanli ($ST_{36}$). As needle force measurement system's coefficient of viscosity, apple and cucumber's coefficient of viscosity were similar to Zusanli ($ST_{36}$)'s. Conclusions : In this study, We compared the practitioners' needle sensation of Zusanli ($ST_{36}$) and six kinds of tissue models with needle force measurement system that can quantify the needle sensation. As the result, we concluded that practitioners' needle sensation is similar to measured needle sensation. It seems that the acupuncture practice model implementing the needle sensation to specific acupuncture points can be built based on the system in this study.

• 제어로봇시스템학회논문지
• /
• 제21권5호
• /
• pp.413-420
• /
• 2015

This paper describes the design of an elbow rehabilitation robot based on force measurement that enables a severe stroke patient confined to their bed to receive elbow rehabilitation exercises. The developed elbow rehabilitation robot was providewitha two-axis force/torque sensor which can detect force Fz and torque Tz, thereby allowing it to measure therotational force (Tz) exerted on the elbow and the signal force Fz which can be used as a safety device. The robot was designed and manufactured for severe stroke patients confined to bed, and the robot program was manufactured to perform flexibility elbow rehabilitation exercises. Asa result of the characteristics test of the developed rehabilitation robot, the device was safely operated while the elbow rehabilitation exercises were performed. Therefore, it is thought that the developed rehabilitation robot can be used for severe stroke patients.

• 한국추진공학회지
• /
• 제24권3호
• /
• pp.18-30
• /
• 2020

본 연구는 고체추진기관의 추력측정불확도 추정 방법에 관한 것이다. 힘 측정불확도 추정 지침은 ISO와 국내외 기구에서 제공하고 있으나 모든 내용이 실험실에서 운용하는 하중시험기와 하중 센서의 교정을 중심으로 기술되고, 개념적으로 기술되어 있다. 추력시험대 불확도의 주요 원인인 교정식과 선형화 불확도의 추정에 대해서는 해당 지침을 직접 적용할 수는 없다. 본 논문에서는 측정불확도 기본 개념을 이용하여 교정식 불확도와 교정식의 선형화 불확도를 추정하는 식을 만들고, 이를 추력 시험대의 추력측정불확도에 추정하여 적용하였으며, 비교적 간단한 추력측정불확도 추정 방법을 제안하였다.

• Tribology and Lubricants
• /
• 제28권2호
• /
• pp.62-69
• /
• 2012

Atomic force microscopy (AFM) has been widely utilized as a versatile tool not only for imaging surfaces but also for understanding nano-scale interfacial phenomena. By measuring the responses of the photo detector due to bending and torsion of the cantilever, which are caused by the interactions between the probe and the sample surface, various interfacial phenomena and properties can be explored. One of the challenges faced by AFM researchers originates in the physics of measuring the small forces that act between the probe of a force sensing cantilever and the sample. To understand the interactions between the probe and the sample quantitatively, the force calibration is essential. In this work, the procedures used to calibrate AFM instrumentation for nano-scale force measurement in normal and lateral directions are reviewed.

• Smart Structures and Systems
• /
• 제23권2호
• /
• pp.123-139
• /
• 2019

Impact forces induced by external object collisions can cause serious damages to civil engineering structures. While accurate and prompt identification of such impact forces is a critical task in structural health monitoring, it is not readily feasible for civil structures because the force measurement is extremely challenging and the force location is unpredictable for full-scale field structures. This study proposes a novel approach for identification of impact force including its location and time history using a small number of multi-metric observations. The method combines an augmented Kalman filter (AKF) and Genetic algorithm for accurate identification of impact force. The location of impact force is statistically determined in the way to minimize the AKF response estimate error at measured locations and then time history of the impact force is accurately constructed by optimizing the error co-variances of AKF using Genetic algorithm. The efficacy of proposed approach is numerically demonstrated using a truss and a plate model considering the presence of modelling error and measurement noises.

• 한국정밀공학회지
• /
• 제14권10호
• /
• pp.15-27
• /
• 1997

Quasti-static cutting force variations in milling process are measured indirectly using spindle motor current. Quasi-static sensitivity of the spindle motor current is higher than that of the feed motor current. Magnitude of the spindle motor current is independent of cutting direction. The linear relationship between the cutting force and the spimdle motor RMS current at various spindle rotational speed is obtained. Frequency/ Voltage(F/V) converter voltage is measured to identify the spindle speed and to determine the cutting force at various spindle speeds. Overload on the tool during milling process can be detected using the proposed indirect cutting force measurement. Based on these measurements, cutting force is regulated at a constant level by feedrate control.