• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.91-96
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• 2006

Presently, cycle-slip detection is done between adjacent two points in many cycle-slip methods. Inherently, it is simple wavelet analysis. A new idea is put forward that the number of difference point can adjust by a parameter factor; we study this method to smooth raw data and detect cycle-slip with wavelet analysis. Taking CHAMP satellite data for example, we get some significant conclusions. It is showed that it is valid to detect cycle-slip in GPS phase measurement based on this wavelet function, and it is helpful to improve the precision of GPS data pre-processing and positioning.

• Journal of Positioning, Navigation, and Timing
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• 제6권4호
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• pp.181-194
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• 2017

In recent years, research has been actively conducted on the navigation in an indoor environment where Global Navigation Satellite System signals are unavailable. Among them, a study performed indoor navigation by integrating pseudolite carrier and Inertial Measurement Unit (IMU) sensor. However, in this case, there was no solution for the cycle slip occurring in the carrier. In another study, cycle slip detection and compensation were performed by integrating Global Positioning System (GPS) and IMU in an outdoor environment. However, in an indoor environment, cycle slip occurs more easily and frequently, and thus the occurrence of half cycle slip also increases. Accordingly, cycle slip detection based on 1 cycle unit has limitations. Therefore, in the present study, the aforementioned problems were resolved by performing indoor navigation through the integration of pseudolite and ultra-low-cost IMU embedded in a smartphone and by performing half cycle slip detection and compensation based on this. In addition, it was verified through the actual implementation of real-time navigation.

• 한국항행학회논문지
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• 제17권6호
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• pp.593-599
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• 2013

본 논문은 차량 환경에서 GPS 반송파 기반 위치 결정을 위한 반송파 불연속 측정치 검출에 대한 내용을 다룬다. 반송파 기반 위치 결정 방식에 있어서 위치 정확도의 신뢰도를 확보하기 위해서는 반송파 불연속 측정치를 검출해야 한다. 반송파 불연속 측정치를 검출하는 방식에는 여러 연구가 있지만 본 연구에서는 차분된 반송파 측정치와 저가의 관성센서를 이용해 추정한 차분된 반송파의 차이를 모니터링 값으로 설정함으로써 GPS 불연속 측정치를 검출한다. 저가의 불연속 측정치 검출 알고리즘을 개발하는 것을 목표로 설계된 불연속 측정치 검출 성능 만족을 위한 관성센서 성능 범위를 도출한다. 이를 통해 적절한 가격과 성능의 관성센서 선택이 가능하다. 선정된 관성센서가 설계치를 만족하는지를 검증하기 위하여 회전 테이블 실험을 진행하였다. 결과적으로 실험치가 설계된 불연속 측정치 검출 성능을 보수적으로 만족하는 검출 성능을 보였다.

• 대한인간공학회지
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• 제10권2호
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• pp.51-55
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• 1991

Since slipping has been identified as a major hazard, it is important to understand the mechanism of a slip. Many researches, based on biomechanical studies, had been attempted to do that. Thowever, the correlation between the mechanism of a slip and psychophysical behaviors of people had rarely been verified. For example, the existence of small slips in a forward direction, which do not normally perceived by human subjects, has been established by several experimenters. However, the term "microslips are not perceived by the walkers[4]." has not been examined precisely by any experiments. The objective of this study is, using a Signal Detection Theory (SDT), to define a microslip and slip more quqntitatively with the biomechanical measurement of slip distance. The results showed that, the slip distance around the 3 centimeters, there was a obvious change in the accident detectability of the subject. The conclusion is that it is possible to identify the boundary of a microslip and slip around the 3 centermeters of slip distance.

• 재활복지공학회논문지
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• 제8권3호
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• pp.169-175
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• 2014

본 연구에서는 전동휠체어 주행 시, 슬립 현상으로 인해 발생할 수 있는 경로 이탈 및 제어 불능에 대처할 수 있는 슬립 제어기에 관한 연구로 주요기능인 슬립 검출기를 제안하고자 한다. 전동휠체어에서 슬립의 검출은 주행과정에서 전동휠체어와, 모터의 상태를 검출하는 것으로, 이를 위해 6축 IMU 센서와 좌우 모터에 연결되어 있는 엔코더를 통해 산출된 정보를 슬립 검출 알고리즘을 이용하여 슬립율을 산출한다. 이렇게 산출된 슬립 비율은 전동휠체어의 안전성 향상을 위한 제어변수로 사용된다. 본 연구에서 제안한 슬림 검출기 실험 결과 제안된 경로에서의 슬립 현상을 확인 할 수 있었다. 실험 중 최대 슬립 율 검출 구간은 전동휠체어의 선회시 발생하는 것으로 확인 하였다.

• 한국정밀공학회지
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• 제31권2호
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• pp.157-164
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• 2014

In this paper, we design a gripping force control system using tactile sensor to prevent slip when gripper tries to grasp and lift an object. We use a flexible tactile sensor for measuring uniplanar pressure on gripper's finger and develop an algorithm to detect the onset of slip using the sensor output. We also use a flexible pressure sensor to measure the normal force. In addition, various signal processing techniques are used to reduce noise included in the sensor output. A 3-finger gripper is used to grasp and lift up a cylindrical object. The tactile sensor is attached on one of fingers, and sends output signals to detect slip. Whenever the sensor signal is similar to the slip pattern, gripper force is increased. In conclusion, this research shows that slip can be detected using the tactile sensor and we can control gripping force to eliminate slip between gripper and object.

• 전기전자학회논문지
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• 제22권3호
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• pp.539-547
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• 2018

계통 연계형 인버터는 단독운전 조건에서 반드시 전력 공급을 차단해야 한다. 이러한 이유로 분산 발전 시스템은 단독운전을 검출 기능을 반드시 가지고 있어야 한다. 분산 발전용 인버터에 적용되는 일반적인 방법 중에는 Slip-Mode frequency Shift (SMS) 단독운전 검출 기법이 있다. SMS 기법은 계통 전압의 주파수에 따라 무효 전력을 공급하여 단독운전 조건에서 계통 주파수를 허용 범위 밖으로 이동시키는 방법이다. SMS 기법은 안정적으로 단독운전을 검출할 수 있으며, 계통 전류에 고주파를 인가하지 않는다는 장점이 있으나, 무효 전류를 인가하기 때문에 계통 역률이 나빠져서 전력 품질의 저하를 가져온다. 본 논문에서는 계통 전원이 연결되어 있는 정상 조건에서 전력 품질 저하가 없는 수정된 SMS 기법을 제안한다. 600W 단상 인버터 실험을 통해 제안된 방법의 유효성을 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.405-407
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• 2000

The most generally implemented method to detect the ground speed of the railway vehicles is to use the rotary type speed sensor attached to wheel axle. The Slip or sliding phenomenon on the railway vehicles occurs frequently caused by the weak viscosity of the wheel. Thus, precisely to control the car, the slip/sliding detection system is required. In this paper we proposed for the speed data management system, which uses rotary type speed sensor. Proposed speed management system can detect the slip/sliding with wheel axle as well as correct the generated speed error during in error time, to provide accurate speed and precise location data. The effectiveness for adapting to the railway system is clarified by the computer simulation.

• 대한기계학회논문집
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• 제19권7호
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• pp.1581-1589
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• 1995

The feasibility of using AE for detecting contact and slip between a workpiece and an end effector has been tested. Specifically, the relationship between the contact and slip motion and the characteristics of the AE signal is theoretically and experimentally investigated. The experimental results manifest that the high sensitivity of AE signal to the contact and slip makes it a good alternative as a robot tactile sensor.

• Annals of Rehabilitation Medicine
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• 제39권6호
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• pp.897-904
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• 2015

Objective To investigate differences in plantar pressure distribution between a normal gait and unpredictable slip events to predict the initiation of the slipping process. Methods Eleven male participants were enrolled. Subjects walked onto a wooden tile, and two layers of oily vinyl sheet were placed on the expected spot of the 4th step to induce a slip. An insole pressure-measuring system was used to monitor plantar pressure distribution. This system measured plantar pressure in four regions (the toes, metatarsal head, arch, and heel) for three events: the step during normal gait; the recovered step, when the subject recovered from a slip; and the uncorrected, harmful slipped step. Four variables were analyzed: peak pressure (PP), contact time (CT), the pressure-time integral (PTI), and the instant of peak pressure (IPP). Results The plantar pressure pattern in the heel was unique, as compared with other parts of the sole. In the heel, PP, CT, and PTI values were high in slipped and recovered steps compared with normal steps. The IPP differed markedly among the three steps. The IPPs in the heel for the three events were, in descending order (from latest to earliest), slipped, recovered, and normal steps, whereas in the other regions the order was normal, recovered, and slipped steps. Finally, the metatarsal head-to-heel IPP ratios for the normal, recovered, and slipped steps were $6.1{\pm}2.9$, $3.1{\pm}3.0$, and $2.2{\pm}2.5$, respectively. Conclusion A distinctive plantar pressure pattern in the heel might be useful for early detection of a slip event to prevent slip-related injuries.