• 제어로봇시스템학회논문지
• /
• 제16권10호
• /
• pp.969-974
• /
• 2010

In this paper, we propose a fault-tolerant controller for compensating measurement noise of feedback sensor. Because control systems operate via feedback sensor's signal, the measurement noise in sensor's signal results in performance degradation or even system failure. Therefore, control systems often demand on compensating measurement noise. Our controller is equipped with a compensator in order to reject or reduce the effect of measurement noise in feedback information. Our proposed method is verified via simulation and experiment for a Ball and Beam system.

• 한국정밀공학회지
• /
• 제20권3호
• /
• pp.187-193
• /
• 2003

This paper presents an on-machine measurement method of flatness error fur surface machining processes. There are two kinds of on-machine measurement methods available to measure flatness errors in workpieces: i.e., surface scanning method and sensor scanning method. However, motion errors are often engaged in both methods. This paper proposes an idea to realize a measurement system of flatness errors and its rigorous application for estimation of motion errors of the positioning system. The measurement system is made by modifying the straightness measurement system, which consists of a laser, a CCD camera and processing system, a sensor head, and some optical units. The sensor head is composed of a retroreflector, a ball and ball socket, a linear motion guide unit and adjustable arms. The experimental .results show that the proposed method is useful to identify flatness errors of machined workpieces as well as motion errors of positioning systems.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 춘계학술대회논문집
• /
• pp.655-662
• /
• 2007

This paper presents a disk-type capacitive sensor for simultaneous measurement of five-dimensional motions of a target. The sensor can be manufactured with a printed circuit board (PCB) such that the sensor can be integrated with its electronics in a single PCB board, whereby the manufacturing costs is considerably reduced. The sensor is optimally designed through an error analysis of possible mechanical errors. Furthermore, the sensor can correct the horizontal motion measurement errors due to the sensor installation tilting error. A proto-type PCB sensor, electronics and a test rig were built, and the effectiveness of the developed sensor was proved through experiments.

• 한국전기전자재료학회논문지
• /
• 제26권9호
• /
• pp.669-676
• /
• 2013

In this study, we introduce a polymer(polyimide) based pressure sensor to measure real-time heart beat and blood pressure. The sensor have been designed with consideration of skin compatibility of material, cost effectiveness, manufacturability and wireless detection. The designed sensor was composed of inductor coils and an air-gap capacitor which generate self-resonant frequency when electrical source is applied on the system. The sensor was obtained with metalization, etching, photolithography, polymer adhesive bonding and laser cutting. The fabricated sensor was shaped in circular type with 10mm diameter and 0.45 mm thickness to fit radial artery. Resonant frequencies of the fabricated sensors were in the range of 91~96 MHz on 760 mmHg pressurized environment. Also the sensor has good linearity without any pressure-frequency hysteresis. Sensitivity of the sensor was 145.5 kHz/mmHg and accuracy was less than 2 mmHg. Real-time heart beat measurement was executed with a developed hand-held measurement system. Possibility of real-time blood pressure measurement was showed with simulated artery system. After installation of the sensor on skin above radial artery, simple real blood pressure measurement was performed with 64 mmHg blood pressure variation.

• 한국정밀공학회지
• /
• 제30권6호
• /
• pp.607-614
• /
• 2013

In this study, effect of the sensor gain error is theoretically analyzed and simulated when mixed sequential two-prove method(MTPM) is applied for the precision measurement of straightness error of a linear motion table. According to the theoretical analysis, difference of the gain errors between two displacement sensors increases measurement error dramatically and alignment error of the straightedge is also amplified by the sensor gain difference. On the other hand, if the gain errors of the two sensors are identical, most of error terms are cancelled out and the alignment error doesn't give any influence on the measurement error. Also the measurement error of the straightness error is minimized compared with that of the straightedge's form error owing to close relationship between straightness error and angular motion error of the table in the error terms.

• 제어로봇시스템학회논문지
• /
• 제22권2호
• /
• pp.89-96
• /
• 2016

This paper describes the design of a force measurement and communication system for the force measuring system in industrial robots. The force measurement and communication system is composed of a multi-axis force sensor and a controller for measuring the forces (x-direction force, y-direction force and z-direction force) and sending the measured forces to the robot's controller (PLC: Programmable Logic Controller). In this paper, the force measurement and communication system was designed and fabricated by using a DSP (Digital Signal Processor). An environment test and a grinding and deburring test using an industrial robot with the force measurement and communication system with three-axis force sensor were carried out to characterize the system. The tests showed that the system could safely measure the forces from the three-axis force sensor and send the measured forces to the industrial robot's controller while the grinding and deburring test was performed. Thus, it is thought that the fabricated force measurement and communication system could be used for controlling the force for an industrial robot's grinding and deburring.

• International journal of advanced smart convergence
• /
• 제8권4호
• /
• pp.154-160
• /
• 2019

In this paper, we propose the miniaturization size of wearable Range of Motion(ROM) and a system that can be connected with smart devices in real-time to measure the joint movement range dynamically. Currently, the ROM of the joint is directly measured by a person using a goniometer. Conventional methods are different depending on the measurement method and location of the measurement person, which makes it difficult to measure consistently and may cause errors. Also, it is impossible to measure the ROM of joints in real-life situations. Therefore, the wearable sensor is attached to the joint to be measured to develop a miniaturize size ROM device that can measure the range of motion of the joint in real-time. The sensor measured the resistance value changed according to the movement of the joint using a load cell. Also, the sensed analog values were converted to digital values using an Analog to Digital Converter(ADC). The converted amount can be transmitted wireless to the smart device through the wearable sensor node. As a result, the developed device can be measured more consistently than the measurement using the goniometer, communication with IoT-based smart devices, and wearable enables dynamic observation. The developed wearable sensor node will be able to monitor the dynamic state of rehabilitation patients in real-time and improve the rapid change of treatment method and customized treatment.

• 제어로봇시스템학회논문지
• /
• 제20권11호
• /
• pp.1136-1141
• /
• 2014

This paper proposes a new contact type ball tracking sensor to improve the control performance of a low cost ball-and-beam system. It is well-known that the impulsive measurement noise contained in ball position measurement is one of the factors which severely degrades the ball-and-beam control performance. The impulsive ball position measurement noises often appear under the sporadical ball floating on the beam. This fact motivates us to devise a simple analog preprocessing circuit to determine whether the ball loses the contact or not. Once the abnormal ball position measurement is detected, the design problem of the ball tracking sensor can be cast into the typical state estimation problem with missing data. In order to tackle the real-time implementation issue, a steady-state Kalman filter is applied to the problem. Through the experimental results, the usefulness of the proposed scheme is demonstrated.

• 한국항공우주학회지
• /
• 제31권6호
• /
• pp.30-35
• /
• 2003

본 논문에서는 편광 유지 광섬유 브래그 격자(PMFBG) 센서를 제작하고 신호특성을 파악하였으며, 횡방향 변형률(transverse strain)을 측정하였다. PMFBG 센서는 위상 마스크와 엑시머 레이저를 이용해서 제작하였으며, 반사파는 내부 복굴절율의 영향으로 기존의 FBG 센서와 다르게 두개의 피크를 가지는 것을 확인할 수 있었다. 또한 PMFBG 센서는 자체적으로 2개의 광축을 가지고 있으므로 이 광축을 찾는 실험을 수행하였다. 제작된 PMFBG 센서를 에폭시 시편에 삽입하여, 센서에 가해지는 횡방향 변형률을 측정하였다. PMFBG 센서의 광원으로서 파장 이동 광섬유 레이저(WSFL)를 사용하였다. 실험결과, PMFBG 센서로 측정된 변형률은 스트레인 게이지로 측정한 변형률과 잘 일치하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1067-1070
• /
• 2003

In this paper, we present a remote measurement system for the wireless monitoring of ECU Sensor Signals of vehicle. In order to measure the ECU sensor signals, the interface circuit is designed to communicate ECU and designed terminal wirelessly according to the ISO, SAE regulation of communication protocol standard. A micro-controller 80C196KC is used for communicating ECU sensor signals. ECU sensor signals are transmitted to the RF-wireless terminal that was developed using the micro controller 80386EX. LCD, and RF-module. 80386EX software is programmed to monitor the ECU sensor signals using the Borland C++ compiler in which the half duplex method was used for the RS232 communication. The algorithms for measuring the ECU sensor signals are verified to monitor ECU state. At the same time, the information to fix the vehicle's problem can be shown on the developed monitoring software. The possibility for remote measurement of ECU sensor signals using 80386EX is also verified through the developed systems and algorithms.