• Title/Summary/Keyword: robust positioning system

Search Result 118, Processing Time 0.024 seconds

Mechanism Development and Position Control of Smart Buoy Robot

  • Park, Hwi-Geun;Kim, Hyun-Sik
    • Journal of Ocean Engineering and Technology
    • /
    • v.35 no.4
    • /
    • pp.305-312
    • /
    • 2021
  • There is a gradual increase in the need for energy charging in marine environments because of energy limitations experienced by electric ships and marine robots. Buoys are considered potential energy charging systems, but there are several challenges, which include the need to maintain a fixed position and avoid hazards, dock with ships and robots in order to charge them, be robust to actions by birds, ships, and robots. To solve these problems, this study proposes a smart buoy robot that has multiple thrusters, multiple docking and charging parts, a bird spike, a radar reflector, a light, a camera, and an anchor, and its mechanism is developed. To verify the performance of the smart buoy robot, the position control under disturbance due to wave currents and functional tests such as docking, charging, lighting, and anchoring are performed. Experimental results show that the smart buoy robot can operate under disturbances and is functionally effective. Therefore, the smart buoy robot is suitable as an energy charging system and has potential in realistic applications.

Experiments on Robust Nonlinear Control for Brush Contact Force Estimation (연마 브러시 접촉력 산출을 위한 비선형 강건제어기 실험)

  • Lee, Byoung-Soo
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.27 no.3
    • /
    • pp.41-49
    • /
    • 2010
  • Two promising control candidates have been selected to test the sinusoidal reference tracking performance for a brush-type polishing machine having strong nonlinearities and disturbances. The controlled target system is an oscillating mechanism consisting of a common positioning stage of one degree-of-freedom with a screw and a ball nut driven by a servo motor those can be obtained commercially. Beside the strong nonlinearity such as stick-slip friction, the periodic contact of the polishing brush and the work piece adds an external disturbance. Selected control candidates are a Sliding Mode Control (SMC) and a variant of a feedback linearization control called Smooth Robust Nonlinear Control (SRNC). A SMC and SRNC are selected since they have good theoretical backgrounds, are suitable to be implemented in a digital environment and show good disturbance and modeling uncertainty rejection performance. It should be also noted that SRNC has a nobel approach in that it uses the position information to compensate the stickslip friction. For both controllers analytical and experimental studies have been conducted to show control design approaches and to compare the performance against the strong nonlinearity and the disturbances.

In-Vehicle AR-HUD System to Provide Driving-Safety Information

  • Park, Hye Sun;Park, Min Woo;Won, Kwang Hee;Kim, Kyong-Ho;Jung, Soon Ki
    • ETRI Journal
    • /
    • v.35 no.6
    • /
    • pp.1038-1047
    • /
    • 2013
  • Augmented reality (AR) is currently being applied actively to commercial products, and various types of intelligent AR systems combining both the Global Positioning System and computer-vision technologies are being developed and commercialized. This paper suggests an in-vehicle head-up display (HUD) system that is combined with AR technology. The proposed system recognizes driving-safety information and offers it to the driver. Unlike existing HUD systems, the system displays information registered to the driver's view and is developed for the robust recognition of obstacles under bad weather conditions. The system is composed of four modules: a ground obstacle detection module, an object decision module, an object recognition module, and a display module. The recognition ratio of the driving-safety information obtained by the proposed AR-HUD system is about 73%, and the system has a recognition speed of about 15 fps for both vehicles and pedestrians.

Interactive Navigational Structures

  • Czaplewski, Krzysztof;Wisniewski, Zbigniew
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • v.1
    • /
    • pp.495-500
    • /
    • 2006
  • Satellite systems for objects positioning appeared indispensable for performing basic tasks of maritime navigation. Navigation, understood as safe and effective conducting a vehicle from one point to another, within a specific physical-geographical environment. [Kopacz, $Urba{\acute{n}}ski$, 1998]. However, the systems have not solved the problem of accessibility to reliable and highly accurate information about a position of an object, especially if surveyed toward on-shore navigational signs or in sea depth. And it's of considerable significance for many navigational tasks, carried out within the frameworks of special works performance and submarine navigation. In addition, positioning precisely the objects other than vessels, while executing hydrographical works, is not always possible with a use of any satellite system. Difficulties with GPS application show up also while positioning such off-lying dangers as wrecks, underwater and aquatic rocks also other naturaland artificial obstacles. It is caused by impossibility of surveyors approaching directly any such object while its positioning. Moreover, determination of vessels positions mutually (mutual geometrical relations) by teams carrying out one common tasks at sea, demands applying the navigational techniques other than the satellite ones. Vessels'staying precisely on specified positions is of special importance in, among the others, the cases as follows: - surveying vessels while carrying out bathymetric works, wire dragging; - special tasks watercraft in course of carrying out scientific research, sea bottom exploration etc. The problems are essential for maritime economy and the Country defence readiness. Resolving them requires applying not only the satellite navigation methods, but also the terrestrial ones. The condition for implementation of the geo-navigation methods is at present the methods development both: in aspects of their techniques and technologies as well as survey data evaluation. Now, the classical geo-navigation comprises procedures, which meet out-of-date accuracy standards. To enable meeting the present-day requirements, the methods should refer to well-recognised and still developed methods of contemporary geodesy. Moreover, in a time of computerization and automation of calculating, it is feasible to create also such software, which could be applied in the integrated navigational systems, allowing carrying out navigation, provided with combinatory systems as well as with the new positioning methods. Whereas, as regards data evaluation, there should be applied the most advanced achievements in that subject; first of all the newest, although theoretically well-recognised estimation methods, including estimation [Hampel et al. 1986; $Wi{\acute{s}}niewski$ 2005; Yang 1997; Yang et al. 1999]. Such approach to the problem consisting in positioning a vehicle in motion and solid objects under observation enables an opportunity of creating dynamic and interactive navigational structures. The main subject of the theoretical suggested in this paper is the Interactive Navigational Structure. In this paper, the Structure will stand for the existing navigational signs systems, any observed solid objects and also vehicles, carrying out navigation (submarines inclusive), which, owing to mutual dependencies, (geometrical and physical) allow to determine coordinates of this new Structure's elements and to correct the already known coordinates of other elements.

  • PDF

Position and Orientation Recognition for Adjusting Electronic Tuners (전자 튜너 조정을 위한 위치와 방향 인식)

  • Yang, Jae-Ho;Kong, Young-June;Lee, Moon-Kyu
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.16 no.2 s.95
    • /
    • pp.39-49
    • /
    • 1999
  • This paper describes the development of a vision-aided position and orientation recognition system for automatically adjusting electronic tuners which control the waveform by rotating variable resisters. The position and orientation recognition system estimates the center and the angle of the tuner grooves so that the main controller may correct the difference from the ideal position and thereby manipulate the variable resisters automatically. In this paper a robust algorithm is suggested which estimates the center and the angle of the tuner grooves fast and precisly from the source image with lighting variance and video noise. In the algorithm morphological filtering, 8-chain coding, and invariant moments are sequentially used to figure out image segments concerned. The performance of the proposed system was evaluated using a set of real specimens. The results indicate the system works well enough to be used practically in real manufacturing lines. If the system adopts a high speed frame grabber which enables real time image processing, it can also be applied to positioning of robot manipulators as well as automated PCB adjusters.

  • PDF

Design and Implementation of Assisted GPS Navigation Systems Using TPEG Protocol of Terrestrial DMB Data Services (지상파 DMB 데이터 서비스의 TPEG프로토콜을 이용한 Assisted GPS 항법 시스템의 설계 및 구현)

  • Kim, Byung-Soo;Min, Seung-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.11B
    • /
    • pp.1618-1623
    • /
    • 2010
  • In this paper, we propose a new assisted global positioning system (A-GPS) using terrestrial digital multimedia broadcasting (T-DMB) data services. Because of the weak signal strength from GPS satellite and the signal blockage, it is difficult for the telematics terminal to determine the position in urban area. Proposed A-GPS system calculates pseudo range (PR) from timing information of GPS satellites and obtains the satellite information such as ephemeris from T-DMB station to determine the current position. Compared to conventional GPS system, the proposed system has better performance in terms of the fast time to first fix (TTFF), low horizontal dilution of precision (HDOP). Experimental results show that the proposed system is a feasible and robust solution.

Actuator Control of Throttle Valve of An Automobile

  • Lee, Kyung-Moon;Lee, Jung-Yong;Kim, Gun-Tae;Lee, Jang-Myung
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.602-607
    • /
    • 2004
  • Accurate and quick positioning of the throttle valve in driving situation is required to implement the Traction Control System(TCS). Also, unlike a conventional throttle valve which is connected to the accelerator directly by a wire, an Electronic Throttle Valve(ETV) is driven by a DC motor and can move dependently upon the accurate position of the accelerator. In the research, the Electronic Throttle Body(ETB) and Controller for TCS application was developed. In order to drive the DC motor, the developed controller was built and interfaced to the ECU and ETB. The PID position control algorism and developed systems are designed to realize the robust tracking control of the ETV. Actual vehicle tests with these systems and PID position control algorithm. Finally, the performance of the proposed those are evaluated with the experimental studies.

  • PDF

Analysis and Improvement of Dynamics Characteristic of 3-axis Nano Stage (3 축 나노 스테이지 동특성 해석 및 개선)

  • Kim, Choong;Lee, Kang-Nyung;Lee, Dong-Ju;Lee, Moon-Gu;Choi, Hyoung-Gil;Lee, Suk-Won;Park, No-Cheol;Park, Young-Pil
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.05a
    • /
    • pp.555-558
    • /
    • 2005
  • The precision positioning system requires robust design to obtain enough bandwidth. Therefore, The sub-resonance occurred by the disaccord of force center and mass center should be oppressed. And it is necessary to move the flexible mode to a higher frequency. In this paper, the 3-axis nano stage was proposed and dynamic characteristics was improved by design of experiments (DOE).

  • PDF

Marker Recognition Method Robust against Illumination Changes for Mobile Indoor Navigation (모바일 실내 내비게이션을 위한 실내 조명 변화에 강한 마커인식 방법)

  • Choi, Tae-Woong;Lee, Hyun-Cheol;Hur, Gi-Taek;Kim, Eun-Seok
    • Proceedings of the Korea Contents Association Conference
    • /
    • 2011.05a
    • /
    • pp.59-60
    • /
    • 2011
  • 요즘 스마트 디바이스의 보급으로 스마트 디바이스를 통한 다양한 정보제공 서비스 또한 빠르게 증가하고 있다. 본 논문에서는 GPS(Global Positioning System) 센서 이용이 제한적인 실내와 같은 좁은 공간에서 스마트 디바이스 통한 내비게이션시 다양한 정보를 제공할 수 있는 실내 조명변화에 강한 마커 인식 방법을 제안한다. 제안 방법은 형태가 비슷한 실내 공간과 조명이 제한적이거나 급격하게 변하는 상황에서 견고하고 정밀한 위치 추적을 통해 정확한 서비스를 제공할 수 있게 해 줄 것이다.

  • PDF

An Image-Based Stereo visual Servoing Algorithm Robust to the Camera Extrinsic Parameters (카메라 외적 파라메터에 대하여 강인성을 갖는 스테레오 시각 제어 알고리즘)

  • Dong Min Kim
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.4 no.6
    • /
    • pp.753-758
    • /
    • 1998
  • 본 논문은 카메라 파라메터의 측정오차에 대하여 강인성을 보이는 새로운 로봇의 스테레오 시각 위치제어 알고리즘을 제시한다. 제시된 알고리즘은 카메라로부터 측정된 영상 데이터만을 이용함으로써, 특히 파라메터 측정오차에 대하여 매우 민감함을 보이는 영상 데이터로부터 작업 공간에서의 위치로의 변환, 즉 역변환 추정장치의 필요성을 제거하였다. 이러한 특징이 기존 개발된 시각 제어기와의 큰 차이를 두고 있다. 그럼에도 불구하고 제시된 제어기는 전 작업 영역 내에서 시스템 안정성을 갖는다. 또한 카메라의 위치 측정 오차에 대하여 전혀 영향을 받지 않음이 증명되어지고 방향 폭정 오류에 대해서도 기존 제어기보다 강인함을 시뮬레이션을 통하여 보여진다.

  • PDF