• Journal of Institute of Control, Robotics and Systems
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• v.17 no.3
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• pp.218-222
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• 2011

This paper proposes a single-joint optical torque sensor with one body structure. Conventional optical torque sensors consist of three parts, two plates and an elastic structure. They have slightly slipping problem between plates and elastic structure due to the manufacturing tolerance. Since the order of measurement range of optical sensor is about ten micrometers, the slipping problem causes large measurement error, especially in the case of vibrational or high speed plant. This problem does not occur in the proposed design due to the one body structure. The proposed sensor has advantage of low cost, light weight, and small size. And it is easy to design and manufacture. Simulation works that analysis of stress and strain are performed accurately. To demonstrate the performance of proposed sensor, experiments were implemented to compare with a commercial force/torque sensor (ATI Mini45).

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.12
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• pp.1195-1200
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• 2007

Torque of a rotating shaft has been mostly measured by strain gages combined with either a slip ring or telemetry. However, these methods have severe inherent problems like low S/N ratio, high cost, limited number of channels and difficult installation. In this paper, a new method using FBG(fiber bragg grating) sensors and a rotary optical coupler for online non-contact torque monitoring is suggested. FBG sensor can measure both strain and temperature, and has much batter characteristics than those of a strain gage. A rotary optical coupler is a optical connecting device between a rotating shaft and stationary side without any physical contact. It has been devised for transmitting light between a rotating optical fiber and a stationary optical fiber. The proposed method uses this rotary optical coupler to connect FBG sensors on the rotating shaft to instruments at stationary side. And a reference FBG sensor is also applied to compensate the insertion loss change of the rotary optical coupler due to rotation. Three FBG sensors have been fabricated in a single optical fiber. Two FBG sensors are attached on the shaft surface to measure torque and one sensor is installed at the shaft center to compensate the insertion loss change. The torque of a rotating shaft has been successfully measured by the suggested method proving its superior performance potential.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1593-1594
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• 2011

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.10-19
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• 1996

This paper presents a finger-shaped multisensor system which can measure the tyep and position of a target surface by contactl. The multi-sensor system consists of a sphere-shpaed optical tactile sensor located at the finger tip and a force/torque sensor located at the joint of a finger. The optial tactile sensor determines the type and position of the target surface using the shape and position of the CCD image of the touching area generated by a contact between the sensor and the taget surface. The force/torque sensor also determines the position and surface normal vector by applying the distributionof forces and torques t the contact point to the equations of finger shape. The measurements on the position and surface normal vector at a contact point obtined by two individual sensors are fused using a statistical method. The integrated sensor system has 0.8mm error in position measurement and 1.31$^{\circ}$ error in normal vector measurement. The developed sensor system has many applications, such as autonomous compliance control, automatic grasping and recognition, etc.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.628-631
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• 1996

This paper proposes a surface recognition algorithm which determines the types of contact surfaces by fusing the information collected by the multisensor system, consisted of the optical tactile and force/torque sensors. Since the image shape measured by the optical tactile sensor system, which is used for determining the surface type, varies depending on the forces provided at the measuring moment, the force information measured by the f/t sensor takes an important role. In this paper, an image contour is represented by the long and short axes and they are fuzzified individually by the membership function formulated by observing the variation of the lengths of the long and short axes depending on the provided force. The fuzzified values of the long and short axes are fused using the average Minkowski's distance. Compared to the case where only the contour information is used, the proposed algorithm has shown about 14% of enhancement in the recognition ratio. Especially, when imposing the optimal force determined by the experiments, the recognition ratio has been measured over 91%.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.2
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• pp.27-32
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• 2004

Absolute optical angle sensor is described that is an essentially digital opto-electronic device. Its purpose is to resolve the relative and absolute angle position of coded disk using Pseudorandom-code and Geometry-code. In this technique, the angular position of disk is determined in coarse sense first by Pseudorandom-code. A further fine angular position data based on Pixel count is obtained by Geometry-code which result 0.006$^{\circ}$ resolution of the system provided that 7 ${\mu}{\textrm}{m}$ line image sensor are used. The proposed technique is novel in a number of aspects, such that it has the non-contact reflective nature, high resolution of the system, relatively simple code pattern, and inherent digital nature of the sensor. And what is more the system can be easily modified to torque sensor by applying two coded disks in a manner that observe the difference in absolute angular displacement. The digital opto-electronic nature of the proposed sensor, along with its reporting of both torque and angle, makes the system ideal for use in intelligent vehicle systems. In this communication, we propose a technique that utilizes Pseudorandom-code and Geometry-code to determine accurate angular position of coded disk. We present the experimental results to demonstrate the validity of the idea.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1907-1912
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• 2016

In fact, in order to obtain good performances and low torque ripple, a high-resolution sensor is needed, which is costly and usually needs a special construction for the machine. So researchers are becoming aware of their cost and are exploring the possibility of cost reduction. Information of rotor position is necessary to drive Linear Switched Reluctance Motor(LSRM). Therefore, linear optical encoder is used to detect a mover position. Normally, since the price of encoder, which is used for linear motor is relatively higher than the one used for rotory motor and the cost of additional equipment increases with the length of motor. This is not always appropriate, considering economical efficiency in case of using the linear optical encoder. As a results, LSRM has a great part for the total cost. Therefore, in this paper, we propose LSRM position detecting modeling with reflective type photo-sensor. Additionally, we have investigated the possibility of the reduced position sensor for LSRM drives with advanced control technique. To certify the overall characteristics of the proposed method, a simulation using PSIM software has been carried out and the informative results are displayed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.682-687
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• 2011

Calibration mirror mechanism has been widely used for on-board calibration with black body. The calibration mirror is deployed to reflect the radiation energy from the black body to the image sensor for calibrating the sensor system. After the calibration, the calibration mirror is stowed not to hide a main optical path. It also has a fail-safe function which can stow the mirror by just removing the input power of motor when the calibration mirror is stopped at certain position during the calibration. In the present work, the operation concept, design, torque analysis and functional test results of the calibration mirror mechanism with the aforementioned function have been introduced and investigated.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.559-566
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• 2016

Cables for Towed Array Sonar System(TASS) were developed. In order to verify the performance of cables, environmental and operational conditions as well as functional requirements were investigated during design stage. Double armored high and low voltage integrated cable for towed body and two kinds of cables, armored and light weight power and optic hybrid cables for towed array sensor system were developed by modeling and simulation. Customized manufacturing process and test method, such as foam extrusion and dynamic fatigue test were applied to this development. In conclusion, underwater towed hybrid cable with high tensile strength and compact structure were developed.