• Title/Summary/Keyword: slippery

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Neural network based position estimation of mobile robot in slippery environment (Slip이 발생할 때 신경회로망을 이용한 이동로보트의 위치추정에 관한 연구)

  • 최동엽;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.133-138
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    • 1993
  • This paper presents neural network based position estimation method in slippery environment as an approach to solve one of problems which are engaged in dead reckoning method. Position estimator is composed of slip detector and linear velocity estimator. Both of them are based on the fact that dynamic characteristic of mobile robot in slippery environment is different from the case without slip. To find out the dynamic relation among driving torque, angular acceleration of driving wheel and linear acceleration of mobile robot, accelerometer is used for measuring acceleration of mobile robot and neural network is used for dynamic system identifier in slippery environment.

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Active steering Control Based on The Estimated Tire Forces (추정된 타이어 힘을 이용한 능동 조향 제어)

  • Seo, Chan-Won;Kim, Jun-Yeong;Hong, Dae-Geon;Heo, Geon-Su
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2228-2234
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    • 2000
  • Steering of the vehicles on a slippery highway is a difficult task for most passenger car drivers. The steering vehicles on slippery roads tend to slide outward with less lateral forces than on nor mal roads. When the drivers notice that their vehicles on a slippery highway start to depart from the cornering lane, most of them make a sudden steering and/or braking, which in turn may induce spin-out and instability on their vehicles. In this paper, an active steering control method is proposed such that the vehicles in slippery roads are steered as if they are driven on the normal roads. In the proposed method, the estimated lateral forces acting on the steering tires are compared with the reference values and the difference is compensated by the active steering method. A fuzzy logic controller is designed for this purpose and evaluated on a steering Hardware-In-the-Loop Simulation (HILS) system. Steering performance results on the slippery curved and sinus roads demonstrate the effectiveness of the proposed controller. This method can be realized with the steer-by-wire concept and is promising as an active safety technology.

Development of Functional men-shoes for old people (접질림과 미끄럼 방지를 위한 노인용 남자 구두 개발)

  • 김진호;황인극;박용복
    • Science of Emotion and Sensibility
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    • v.6 no.4
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    • pp.1-7
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    • 2003
  • Shoes adding layer for preventing sprain and slippery for the elderly were developed using the shoe-last based on the Korean anthropometric elderly. The anthropometric elderly, arbitrarily defined as those 65 years of age and above, were a distinct with special needs. The shoe-last for the elderly was also designed in this paper. A total of 9 subjects participated and evaluated each shoes made by developed shoes-last and adding layer for preventing sprain and slippery. As results, the proposed shoes have the better functions for preventing sprain and slippery compared to others.

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Slippery Scar: A New Mushroom Disease in Auricularia polytricha

  • Sun, Jie;Bian, Yinbing
    • Mycobiology
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    • v.40 no.2
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    • pp.129-133
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    • 2012
  • A new disease, the slippery scar, was investigated in cultivated bags of Auricularia polytricha. This fungus was isolated from the infected mycelia of cultivated bags. Based on morphological observation, rDNA-internal transcribed spacer and 18S sequence analysis, this pathogen was identified as the Ascomycete Scytalidium lignicola. According to Koch's Postulation, the pathogenicity of S. lignicola to the mycelia of A. polytricha was confirmed. The parasitism of this fungus on mushroom mycelia in China has not been reported before.

Design of a Propagation Wave Type Microrobot for Moving on the Slippery Surface

  • Kim, Eui-Jin;Park, Jong-Hyeon
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2072-2077
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    • 2003
  • Animal-like robots are serving an important role as a linkage between biology and engineering. So, in this paper, we aim to develop a biomimetic microrobot that mimics the locomotion mechanism of a gastropod. This microrobot has 3 DOF (x, y translation and rotation), and has small size, unlimited traveling range, high resolution and low cost. Its movement can be made using propagation wave that is generated by the controllable sinusoidal voltage source and piezoelectric effects. This soft motion that can be generated by propagation wave and piezoelectric mechanism would be useful for the motion on the slippery surface. So we modeled the propagation wave mechanism including piezoelectric effect and friction on the contact surface, and could know the velocity of the microrobot is dependent on the driving frequency, input voltage peak, propagation wavelength and surface friction coefficient. With these results we design the microrobot, and accomplish its fabrication and experimentation. The development of this microrobot shall be aimed to design an autonomous moving actuator like animal. Also it can be used from micromanipulation system technology to biology and medicine.

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A Study on the Adhesion Control using the Estimated Adhesion for Improving Traction Performance (견인능력 향상을 위한 추정점착력을 이용한 점착제어기법에 관한 연구)

  • Seo, Gwang-Deok
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.12
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    • pp.709-714
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    • 1999
  • This paper is focused on the adhesion control method to improve traction efficiency using the estimated adhesion for railway propulsion system. Recently, the wheel slippery is frequently occurred due to light weight of train and power increasement of traction parts. This phenomenon occurs a traction loss and a poor ride comport. Therefore, the adhesion control which is able to prevent the slippery and to control the traction on a maximum adhesion is absolutely needed. This paper introduces typical methods for adhesion control and proposes two novel adhesion methods using the estimated adhesion.

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The temptation of the slippery slope argument: A research of its nature (미끄러운 경사길 논증의 유혹: 그 실체의 탐구)

  • Lee, Hye-jung
    • Journal of Korean Philosophical Society
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    • v.129
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    • pp.267-290
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    • 2014
  • The slippery slope argument means that if we accept a type of action A, we are committed to accepting B, C and eventually N. Then, N is situation which we must not accept morally. It works causal mechnism that B because A is raised, C because B is raised. But in the logic textbooks and treatises, the slippery slope argument is classified as fallacy. The reason is that the argument is not a causal argument. Actually, it is a probable. Also it is argued that the argument is wrong because it fears about the future extremely. But We can not say all slippery slope argument is fallacy even though a slippery slope argument is sometimes fallacy. I think it is persuasive argument in a significant place. Therefore I argue that the argument is not simple logic as a form of thinking, but practical reasoning applied the context of dialogue. So in order to find it to be practical reasoning we demand the new understanding to fallacy theory. In traditionally, fallacy is defined to wrong reasoning logically, but according to Walton, fallacy means a verbal tactic or deceptive trick that can be used to cause someone to fall down in argument. That is to say, whether or not the argument is successful depends on how it uses as argument tactic in a given context of dialogue. Therefore I argue that whether or not the argument is successful, because of it is practical problem used in a context of dialogue, is to be approached to pragma and dialectical method, not semantic.

Measurement and Strategies for Dynamic Stability During Locomotion on a Slippery Surface (미끄럼 바닥에서 안정성 유지를 위한 균형 전략과 평가방법)

  • Kim, Tack-Hoon;Yoon, Doo-Sik
    • Physical Therapy Korea
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    • v.10 no.1
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    • pp.97-108
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    • 2003
  • Slipping during various kinds of movement often leads to potentially dangerous incidents of falling. The purpose of this paper was to review some of the research performed in the field including such topics as rating scales for balance, kinematics and kinetics of slipping, adaptation to slippery conditions, postural and balance control, and protective movement during falling. Controlling slipping and fall injuries requires a multifaceted approach. Environmental conditions (state of floor surface, tidiness, lighting, etc), work task (walking, carrying, pushing, lifting, etc), and human behavior (anticipation of hazards, adaptation to risks, risk taking, etc) must be accounted for in the assessment of slip and fall-related risks. Future directions of research must deal with modeling of basic tribophysical, biomechanical, and postural control process involved in slipping and falling.

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Traction Control with Brake Pressure Estimation (브레이크 압력 추정을 적용한 구동력 제어)

  • Kim, S.Y.
    • Journal of Drive and Control
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    • v.10 no.3
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    • pp.1-6
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    • 2013
  • Traction control suppresses the spinning of the driven wheel during drive away or acceleration on slippery road condition. In this study, the estimation method of brake pressure hardly measured is proposed. The estimation method of brake pressure and the brake pressure control with pulse width modulation(PWM) are verified a good performance through experiment. Also, the vehicle simulation on slippery road conditions is validated the applicability of brake pressure control for traction control. The simulation results have showed that the brake pressure can be used the control variable for traction control.