Recognition of the Center Position of Electric Line Using Modified Hough Transform

최근 정보사용기기의 급증으로 전력을 안정적으로 공급하는 것이 무엇보다도 중요하다. 특히 안정적인 전력공급을 위하여 활선보수공사를 자율적으로 실현하기 위해 로봇의 자율 제어 기술이 필수적으로 요구되어지고 있다. 본 연구에서는 활선보수공사의 대표작업중 전선의 삽입작업을 대상으로하여, 본 작업을 자율적으로 수행하기 위해 필요한 전선의 3차원 중심위치를 신속, 정확하게 인식하는 알고리즘을 제안한다. 본 연구에서는 기존의 하후변환을 수정하여 2차원 평면에서 전선의 중심위치를 인식하는 알고리즘을 제안하고, 나아가 이를 바탕으로 전선의 3차원 중심 위치를 인식하기 위하여 계산법을 제안한다. 이를 상기 대표작업중 전선의 중심위치의 인식에 응용하여 제안한 인식법의 유효성을 확인하였다.최근 정보사용기기의 급증으로 전력을 안정적으로 공급하는 것이 무엇보다도 중요하다. 특히 안정적인 전력공급을 위하여 활선보수공사를 자율적으로 실현하기 위해 로봇의 자율 제어 기술이 필수적으로 요구되어지고 있다. 본 연구에서는 활선보수공사의 대표작업중 전선의 삽입작업을 대상으로하여, 본 작업을 자율적으로 수행하기 위해 필요한 전선의 3차원 중심위치를 신속, 정확하게 인식하는 알고리즘을 제안한다. 본 연구에서는 기존의 하후변환을 수정하여 2차원 평면에서 전선의 중심위치를 인식하는 알고리즘을 제안하고, 나아가 이를 바탕으로 전선의 3차원 중심 위치를 인식하기 위하여 계산법을 제안한다. 이를 상기 대표작업중 전선의 중심위치의 인식에 응용하여 제안한 인식법의 유효성을 확인하였다

Fluid-Based Triboelectric Nanogenerators- A Review of Current Status and Applications

In the last decades, numerous mechanical energy sources have been utilized as primary energies to produce electricity by using diferent energy harvesting technologies, such as electromagnetic, and piezoelectric technologies. Among these mechanical energy sources, fuid fow energy, defned by water fow and airfow energies, is one of the most important and wide-used renewable energy sources, which is available in nature under the form of raindrops, streams, ocean waves and wind energies. Since the frst introduced in 2012 by Wang’s research group, the triboelectric nanogenerator (TENG) has become one of the most vital innovations in harvesting energy technologies. Many TENGs devices have been developed and demonstrated its potential in harvesting fuid fow energy. Here, a review of the fuid-based TENG (F-TENG) is presented, including water-based and air-based, with the fundamental theories, basic mode of operations, its current designs, and application. The development of F-TENG is demonstrated via the divers of design structure, high potential application for power generation, and high sensitivity for self-powered sensing systems. F-TENG shows promising potential for large-scale application, and hybrid with other energy harvesting technologies. Besides, this article also considers the recent difculties which reduce the performance of F-TENG, then presents the ways for improving their efciencies. Finally, this study provides a point of view based on the facing challenge and future development trend of the F-TENG

A study on the position control of electrohydraulic servo indexing system and inertia load simulator

학위논문(석사) - 한국과학기술원 : 정밀공학과, 1992.2, [ [ii], 60 p. ]한국과학기술원 : 정밀공학과

Finite-Time Fault-Tolerant Control for a Robotic Manipulator With Output Constraint and Uncertainties

This paper proposed a finite-time backstepping control for a robotic manipulator under the presence of actuator fault, saturation constraints, output constraints, and external disturbance to obtain requirements about the robustness, fast convergence, and high accuracy tracking performance. To manage the above challenges, the proposed control is designed on a transformed model with the backstepping approach and extended state observer. The transformed model is resulted from converting a constrained system based on a transformation technique. So, it provides an ability for the proposed control to obtain the prescribed performance of the output response. Additionally, an extended state observer is conducted to deal with the lumped uncertainties in the system. The essential characteristic of the proposed control is no required knowledge of the actuator faults and external disturbance to be available. Furthermore, fractional-order terms are added in the control laws to enhance the rate of output responses. To demonstrate the advantages of the proposed control in terms of global asymptotic stability, the Lyapunov approach is used to verify the whole controlled system in theory. The proposed control is applied to a 2-degree of freedom (DOF) manipulator and simulated by MATLAB Simulink. Its simulation results are compared to other state-of-the-art methods to exhibit the effectiveness of the proposed control

Design of an Adaptive Fuzzy Observer-Based Fault Tolerant Controller for Pneumatic Active Suspension With Displacement Constraint

This paper proposes an adaptive fuzzy observer based fault tolerant controller for a pneumatic active suspension system considering unknown parameters, actuator failures, and displacement constraints. A pneumatic spring is used for a quarter car model to enhance the vibration attenuation performance. Since the pneumatic system contains uncertain nonlinearities, fuzzy logic systems are utilized to approximate unknown nonlinear functions of unmodeled dynamics and various masses of passengers. Besides, a nonlinear disturbance observer is proposed to estimate the effects of the actuator failures, approximation errors, and external disturbances. By utilizing the disturbance estimation and fuzzy approximation techniques, an adaptive fault tolerant control (FTC) is designed to enhance the output performance of the vehicle suspension. Meanwhile, the command filtered scheme is introduced to solve the explosion of complexity problem in the traditional backstepping approach by avoiding virtual controller derivatives. In contrast to previous results, the proposed control can handle the fault tolerant problem and ensure the tracking error of vertical displacement converges into a small-predefined boundary by introducing the prescribed performance function. Moreover, the stability of the closed-loop system is analyzed according to the Lyapunov theory. Finally, comparative simulation examples and experimental studies are performed on the active pneumatic suspension test bench to verify the feasibility of the proposed scheme

Energy saving of hybrid hydraulic excavator with innovative powertrain

An innovative hydraulic hybrid excavator is proposed in this paper to save energy. An electrical hydraulic continually variable powertrain is proposed to drive the main pump, in which both the speed and torque of the engine can be controlled to ensure that the engine working points lie in the high efficiency range with the proposed energy management strategy. An energy regeneration system is adopted to regenerate the potential energy. In addition, an innovative equivalent consumption minimization strategy is formulated to calculate the control commands of the engine, motor/generator, and hydraulic pump to reduce the energy consumption of the system. A test bench is established, and experiments are conducted to verify the energy saving efficiency of the proposed system. As a result, the energy saving efficiency ranges from 36.69% to 45.16%. The fuel consumption and emission of hydraulic excavator are reduced effectively with the proposed system

STABILIZING APPARATUS OF SHIP USING ANTI-ROLLING TANK

횡요방지 탱크를 이용한 선박의 안정화 장치가 개시된다.본 발명의 실시예에 따른 횡요방지 탱크를 이용한 선박의 안정화 장치는 모바일 하버에서 크레인부를 승하강시키는 리프팅 장치의 상단부에 결합된 발판부와, 상기 발판부의 상부에 배열 설치된 복수개의 유니버셜 조인트부와, 상기 유니버셜 조인트부에 각각 피스톤 로드의 끝단부가 결합되고, 작동유가 충진된 실린더몸체를 갖는 댐핑 실린더를 포함한다

Active Fault Tolerant Control System Design for Hydraulic Manipulator With Internal Leakage Faults Based on Disturbance Observer and Online Adaptive Identification

In this paper, an active fault-tolerant control system design is proposed for an n-degree-of-freedom hydraulic manipulator with internal leakage faults and mismatched/matched lumped disturbances. A pair of matched and mismatched disturbance observers is proposed to simultaneously estimate and compensate for the effects of matched/mismatched disturbances on the control system in healthy conditions. The fault detection is achieved when the estimated matched disturbance is larger than a threshold. After that, a novel control reconfiguration law is designed to switch from a normal controller to a fault-tolerant controller with an online identification algorithm based on an adaptive mechanism. The proposed active FTC guarantees the position tracking performance in not only single-fault but also simultaneous-faults conditions. Moreover, the problem of uniting disturbance-observer-based control for external disturbance and adaptive control for parametric uncertainty is solved in a novel approach. Simulation results are conducted in a two-degree-of-freedom hydraulic leg prototype, which verifies the effectiveness of the proposed method