• 펄프종이기술
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• 제34권5호
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• pp.49-55
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• 2002

A new method is proposed for the on-line measurement of the fiber orientation of sheet materials. The measurement of fiber orientation is very important in manufacturing paper sheets, non-woven fabrics, and glass sheets, because fiber orientation strongly affects product properties represented by, for example, dimensional stability of paper. A method developed in this research utilizes anisotropy of dielectric constants of sheet materials as a key characteristic to determine the fiber orientation. The new on-line sensor, consisting of 5 microwave dielectric resonators set in different directions, was designed to detect the fiber orientation while paper is running with high speed on a paper machine. This sensor can determine the direction and the degree of fiber orientation from the measured direction of the maximal dielectric constant and its variation, respectively. The fundamental performance of this system was examined by the static measurement of printing grade paper, which gave a satisfactory result. Then, the dynamic measurements were done at a speed of 1,000 m/min by using a high-speed test-coating machine.

• International Journal of Ocean System Engineering
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• 제1권3호
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• pp.165-170
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• 2011

In this paper, for the accurate estimation of the position and orientation of the UUV (unmanned underwater vehicle), an AHRS (Attitude Heading Reference System) was developed using the IMU (inertial measurement unit) sensor which provides information on acceleration and orientation in the object coordinate and the initial alignment algorithm and the E-KF (extended Kalman Filter). The initial position and orientation of the UUV are estimated using the initial alignment algorithm with 3-axis acceleration and geomagnetic information of the IMU sensor. The position and orientation of the UUV are estimated using the AHRS composed of 3-axis acceleration, velocity, and geomagnetic information and the E-KF. For the performance test of the orientation estimation of the AHRS, a testbed using IMU sensor(ADIS16405) and DSP28335 coded with an E-KF algorithm was developed and its performance was verified through tests.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.161-166
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• 2006

A new fiber orientation sensor has been developed and tested on an actual paper machine to demonstrate its capability to function as a real-time monitoring system. First, we demonstrate the ability of the sensor system to detect the change in the fiber orientation angle while the sensor head, and not the paper, was intentionally rotated from $-90^{\circ}\;to\;+70^{\circ}$ with respect to the paper-traveling direction. Next, we demonstrate that this system can successfully detect the change in the magnitude and angle of fiber orientation in running paper when the direction of material flow on the wire was changed on the paper machine. The angle and magnitude of fiber orientation were independently confirmed by SST and MOA measurements. Furthermore, we found that the system was capable of measuring the basis weight and the moisture content of running paper while detecting the angle and magnitude of fiber orientation.

• 대한의용생체공학회:의공학회지
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• 제32권2호
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• pp.118-126
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• 2011

This study proposes a human body orientation tracking system by inertial and earth magnetic sensors. These sensors were fused by indirect Kalman filter. The proposed tracking system was configured and the filter was implemented. The tracking performance was evaluated with static and dynamic tests. In static test, the sensor was fixed on the floor while its static characteristics was analyzed. In dynamic test, the sensor was held and moved manually for 30 seconds. The dynamic test included x, y, z axis rotations, and elbow flection/extension motions that mimic drinking. For these dynamic motions, the tracking angle error was under $4.1^{\circ}$ on average. The proposed tracking method is expected to be useful for various human body motion analysis.

• Korean Journal of Geomatics
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• 제4권1호
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• pp.23-30
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• 2004

This study aims to establish interior orientation for various types of sensors including frame cameras, panoramic cameras, line cameras, and whisk-broom scanners. To do so, this study suggests the classification of components of interior orientation of which elements are different according to the sensors. This is entailed by incorporation of sensor characteristics into mathematical models of interior orientation parameters are suggested for being used as guidelines in recovering systematic distortions. Finally, the potential errors resulted from the assumption of regarding sensor model of whisk-broom scanner model as that of push-broom scanner are discussed.

• Journal of Mechanical Science and Technology
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• 제15권10호
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• pp.1369-1379
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• 2001

This paper focuses on a development of a sensor system measuring locations of a vehicle to localize a mobile robot while it tracks on the track (location sensor) . Also it focuses on a system configuration identifying the vehicle's orientation and distance from the object while it is stationary at certain station (position sensor) . As for the location sensor it consists of a set of sensors with a combined guiding and counting sensor, and an address-coded sensor to localize the vehicle while moving on the rail. For the position sensor a PSD (Position Sensitive Device) sensor with photo-switches sensor to measure the offset and orientation of the vehicle at each station is introduced. Both sensor systems are integrated with a microprocessor as a data relay to the main computer controlling the vehicle. The location sensor system is developed and its performance for a mobile robot is verified by experiments. The position measuring system is proposed and is robust to the environmental variation. Moreover, the two kinds of sensor systems guarantee a low cost application and high reliability.

• 전기학회논문지
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• 제63권1호
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• pp.132-138
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• 2014

The use of AGVs(Automated Guided Vehicles) are increasing in many factories. The most widely used AGV system is that magnetic tapes are attached on the factory floor to make guided path and an AGV equipped with a magnetic sensor follows the path by sensing magnetic flux. In this AGV system, usually a magnetic sensor is attached on the front end of an AGV to detect the guided path and the sensor generates analog voltages proportional to the magnetic flux. The problem is that the AGV in use has rather big tracking errors because the accurate orientation of the AGV can not be detected by using only one magnetic sensor. In this paper, we propose a method to minimize the path tracking errors. In our method, one additional sensor is attached on the rear end of the AGV to estimate the orientation of the AGV and to control more accurately the AGV according to the estimated orientation of the AGV. We performed several experiments and the results successfully show the feasibility of the proposed method.

• 대한기계학회논문집A
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• 제40권7호
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• pp.659-666
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• 2016

자기교란은 관성/자기센서를 이용한 자세추정시 추정정확도를 저하시키는 주된 원인이다. 본 논문은 저자가 개발한 6축 관성센서를 이용한 센서가속도 추정용 칼만필터의 확장으로서, 9축 관성/자기센서를 이용하여 운동체의 자세가 지속적으로 변화하는 가운데 운동체 주변 자기교란을 정확히 추정하고, 이를 통해 자기교란환경에서도 정확한 3차원 자세를 추정할 수 있는 병렬 칼만필터를 제안한다. 제안하는 필터는 자기교란벡터를 상태변수로 지정하여 명시적으로 추정하며, 병렬구조이므로 설령 극심한 자기교란에 의해 자세추정이 영향을 받더라도 롤과 피치와는 무관하고 요에만 영향이 국한되는 장점을 지닌다. 제안방법은 로봇이나 선박, 항공기처럼 자기적으로 균등하지 않은 환경에서 운용되는 분야에 효과적으로 적용될 수 있다.

• 대한기계학회논문집
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• 제17권9호
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• pp.2191-2204
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• 1993

A sensor system has been developed to measure the posture(position and orientation) of mobile robots working in industrial environments. The proposed sensor system consists of a CCD camera, retro-reflective landmarks, a strobe unit and an image processing board. The proposed hardware system can be built in economic price compared to commercial vision systems. The system has the capability of measuring the posture of mobile robots within 60 msec when a 386 personal computer is used as the host computer. The experimental results demonstrated a remarkable performance of the proposed sensor system in the posture measurement of mobile robots - the average error in position is less than 3 mm and the average error in orientation is less than 1.5.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.217-220
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• 2005

Currently, a number of control points are required in order to achieve accurate geolocation of satellite images. Control points can be generated from existing maps or surveying, or, preferably, from GPS measurements. The requirement of control points increase the cost of satellite mapping, let alone it makes the mapping over inaccessible areas troublesome. This paper investigates the possibilities of modeling an entire imaging strip with control points obtained from a small portion of the strip. We tested physical sensor models that were based on satellite orbit and attitude angles. It was anticipated that orbit modeling needed a sensor model with good accuracy of exterior orientation estimation, rather then the accuracy of bundle adjustment. We implemented sensor models with various parameter sets and checked their accuracy when applied to the scenes on the same orbital strip together with the bundle adjustment accuracy and the accuracy of estimated exterior orientation parameters. Results showed that although the models with good bundle adjustments accuracy did not always good orbit modeling and that the models with simple unknowns could be used for orbit modeling.