• 한국공작기계학회논문집
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• 제14권4호
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• pp.13-21
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• 2005

The affected factors for an accuracy of theodolite system are not only the measurement environment of temperature, illumination, etc. but also the measurement processes of the distance between two theodolites, the distance from theodolite system to scale bar and the distance from theodolite system to targets. We have known that the best collimation distance between two theodolites and the best distance from theodolite system to scale bar is $3{\sim}4m$. This study was performed for searching the best distance from theodolite system to targets on above measurement configuration. And, we could know that the best distance from theodolite system to targets is $2{\sim}6m$ and the system accuracy could be within ${\pm}0.025mm$.

• 한국공작기계학회논문집
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• 제14권3호
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• pp.67-73
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• 2005

An accuracy of theodolite system may be affected by a measurement environment and a measurement distance change from theodolite to scale bar and/or targets. This study was performed for measuring an accuracy when the distance from thodolite system to scale bar was changed $2\~6m$ on the distance 4m between two theodolites. The results showed that an accuracy was ${\pm}0.025mm$ or better when the distance from theodolite system to targets was 3, 4 and 5m. According to the results, it was found that the best distance from theodolite system to scale bar was $3\~4m$ when the collimation distance was $3\~4m$.

• 한국공작기계학회논문집
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• 제14권2호
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• pp.48-54
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• 2005

The theodolite system consists of two theodolites, a scale bar and a target bu. A measurement accuracy of theodolite system is affected by a measurement distance of each equipment. This study was performed fir measuring an accuracy when the distance from theodolite to scale bar was changed 2~ 6 m on two theodolites distance 3 a The results showed thai the measurement accuracy could be $\pm$0.021 mm when the distance from theodolite to target was 2,3 and 6 n Specially, it was found that the maximum measurement accuracy was 10.017mm on theodolite collimation distance 3m and the distance 4 m of the theodolite and scale bar.

• 한국공작기계학회논문집
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• 제13권2호
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• pp.61-68
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• 2004

A non-contact precision measurement system is a theodolite system, a laser tacker and a photogrammetry system etc. Nowadays, the system reaches to a limit of measurement accuracy required from industrial product of middle and large scale. The one of the solutions for this problem is to maximize the accuracy of the existing measurement system. According to it we performed the study far a measurement accuracy of theodolite system when the distance between two theodolites is changed 1m to 5m. We could blow that the changes of distance affect the measurement accuracy of theodolite system and that the maximum measurement accuracy is $\pm$ 0.02 mm on theodolite distance 3∼4 m.

• 동력기계공학회지
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• 제17권5호
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• pp.121-127
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• 2013

In this paper, we propose a distance measurement system for automatic berthing control using a stereo camera mounted on a rotation control device, and a radial pattern target. Automatically controlling the position and attitude of a ship aims to prevent maritime accidents due to human error. Our goal is to measure the relative distance between a ship and an onshore or offshore target for berthing. Therefore, the distance should be continuously measured while tracking a fixed point on a target. To this end, we developed a stereo camerabased distance measurement system that satisfied these requirements. This paper describes the structure and principle of the measurement system. We validate the distance error for target incline due to the relative position and attitude between a camera and a target in miniature scale. In addition, the findings of an experiment in an outdoor environment demonstrate that the proposed measurement system has accuracy within 1 m at a range of 20-100 m which is the acceptable accuracy for automatic berthing.

• 동력기계공학회지
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• 제19권2호
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• pp.27-32
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• 2015

This paper describes a distance measurement system with high accuracy that utilizes a stereo-based camera and a pan-tilt unit for automatically maintaining the positional relationship between a vessel and a target on the side of a facility at a close range. The measurement system offers an advantage in that it can measure the distance to a target while tracking it. In order to improve the ability to control the position of a vessel between it and a target while maintaining the distance especially at a close range, the accuracy of the measurement system has to be improved. The accuracy of the distance measured by our system is increased with revisions of the conclusively generated data of distance measurement. We verified the accuracy of our system from an experiment, which generated results that had an accuracy of 30 mm for distances in the range between 2-8 m.

• 한국정밀공학회지
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• 제24권8호통권197호
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• pp.41-49
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• 2007

In this paper, we proposed a new ultrasonic distance measurement system with high accuracy and long range. To improve accuracy and enlarge range, the time of flight of ultrasonic is calculated by the period detecting method. In the proposed ultrasonic distance measurement system, the ultrasonic transmitter and receiver are separated but synchronized by RF(Radio frequency) module. The experiment has been implemented from short distance 1m to maximum available distance 30m. And the period detecting method is compared with the conventional threshold level method. Experimental results show the accuracy and range of the distance measurement are improved by this period detecting method.

• 한국산업융합학회 논문집
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• 제19권2호
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• pp.62-68
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• 2016

Laser distance measuring systems are used in many fields with high precision. However, when measuring the reflector such as the mirror and the black color, a laser distance measuring system does not guarantee the measurement accuracy. In order to measure the shape of the cargo, this study proposes the radar distance measurement system. The radar distance measuring system is composed of a distance measuring unit with a 24 GHz antenna module, a signal processing and control board and the 1-axis tilting unit. And, this study developed a monitoring program to monitor the measured data. In order to evaluate performance of the developed system, the distance measurement tests are carried out. The distance error was about 6-15 cm. However, considering the size of the cargo, the precision is not a problem. And, cargo shape was measured by using the distance information measured by the 1-axis tilting unit. It could get a 2 dimension shape profile for the cargo stacked in a yard.

• 한국공작기계학회논문집
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• 제13권4호
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• pp.37-43
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• 2004

A measurement accuracy of theodolite system may be affected by a measurement environment, a measurement distance change and so on. This study was performed for measuring an accuracy when the height of scale bar is changed 0.05m, 0.5m, 1m and 1.5m under the distance 3m between two theodolites, the distance 4m from the theodolite system to scale bar and the distance 5m from the thodolite system to the horizontal target bar. And we could know that the best height is 0.05m and 1m.

• 한국정보통신학회논문지
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• 제16권6호
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• pp.1300-1305
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• 2012

본 연구에서는 정확한 운동량 측정을 위하여 가속도 센서, MCU, 그리고 블루투스를 이용한 운동량 측정 시스템을 제안한다. 이러한 시스템은 실시간 무선으로 이동거리 정보를 정확하게 측정할 수 있다. 제작한 운동량 측정 시스템을 이용하여 다양한 모의실험을 하였고, 그 결과를 분석하였다. 분석한 결과를 기성품과 신뢰성 및 정확도에 측면에서 비교를 하였다. 본 연구에서 제안하는 시스템은 13% 정도의 이동거리 오차를 가지는 기성품에 비해 8%이하의 우수한 오차를 보였다. 이러한 시스템은 소형화되어 기성품에 적용되리라 기대한다.