• Title/Summary/Keyword: input shaper

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Robust Multi-Hump Convolution Input Shaper for Variation of Parameter (파라메터 변화에 강인한 Multi-Hump Convolution 입력성형기 설계)

  • Park, Un-Hwan;Lee, Jae-Won
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.5
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    • pp.112-119
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    • 2001
  • A variety of input shaper has been proposed to reduce the residual vibration of flexible structures. Multi-hump input shaper is known to be robust for parameter variations. However, existing approach should solve the more complicated nonlinear simultaneous equations to improve the robustness of the input shaper with the additional constraints. In this paper, by proposing a graphical approach which uses convolution of shaper, the multi-hump convolution input shaper could be designed even if the constraints are added for further robustness. With a mass-damper-spring model, the better performance is obtained using the proposed new multi-hump convolution input shaper.

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Control of the Residual Vibration of Crane Using Equivalent Input Shaper (등가입력성형기를 이용한 크레인의 잔류진동 제어)

  • Park, Un-Hwan;Lee, Jae-Won;Noh, Sang-Hyun;Yoon, Ji-Sup;Park, Byung-Suk
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.1
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    • pp.135-142
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    • 2002
  • Input shaping is a method for reducing residual vibration in computer controlled machines. Vibration is eliminated by convolving a sequence of impulses, an input shaper, with a desired system command to produce a shaped input. This paper shows the shape of sensitivity curve of input shaper as impulse interval T and analysis of robustness for input shaper on the z-plane. And a method is presented for designing equivalent input shaper considering sampling time $T_s$. And then we applied equivalent input shaper to crane system.

Reduction of Residual Vibration for 2 Axes Overhead Crane by Input Shaping (입력성형기법에 의한 2축 천정크레인의 잔류진동 감소)

  • 박운환;이재원;노상현
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.4
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    • pp.181-188
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    • 2000
  • Input shaping is a method fur reducing residual vibration. Vibration is eliminated by convolving an input shaper, which is a sequence of impulses, with the desired system command. It has been applied to robot with a flexible manipulator. But it can be applied to the reduction of residual vibration far overhead crane. In this paper, input shaping shows good performance for anti-sway of overhead crane. In the z-domain, we designed an input shaper and calculated the sensitivity of it. If sensitivity is calculated in the z-domain, the shapes of sensitivity curves are expected easily. Accordingly, it is easy to design an input shaper in the z-domain. We compared the response of a system with shaper to it without that. Also, we compared El shaper to ZV shaper in view of robustness.

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An SD Shaper to Suppress Residual Vibration at an Arbitrarily Specified Duration (임의 성형시간에 잔류진동을 제거할 수 있는 SD성형기)

  • Brian Byunghyun Kang
    • The Journal of Korea Robotics Society
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    • v.18 no.1
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    • pp.127-134
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    • 2023
  • Recently, various input shapers have been introduced to reduce residual vibrations of flexible robots. However, there have been no studies on the design of an input shaper that can suppress residual vibration at an arbitrarily specified duration. In this paper, a novel input shaper called an SD (specified-duration) shaper is proposed for an undamped or underdamped system, which can suppress residual vibration at an arbitrarily given specified duration. If the specified duration is larger than a half period, a positive SD shaper composed of all positive impulses is designed, and if the specified duration is smaller than a half period, a negative SD shaper including a negative impulse is designed. As the specified duration is increased every half period after a half period, the number of impulses of the positive SD shaper is increased one by one, and the robustness of the SD shaper to modeling errors is increased. The performance of the SD shaper is analyzed through simulation studies for an undamped and underdamped second-order systems. The validity of the SD shapers is demonstrated experimentally using an experimental device that can generate container transport motions.

Design of Robust Convolution Input Shaper for the Variation of Frequency and Damping Ratio (주파수와 감쇠비 변화에 강인한 Convolution 입력성형기 설계)

  • Park, Un-Hwan;Lee, Jae-Won;Im, Byeong-Deok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.67-73
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    • 2002
  • The flexibility of long reach manipulators presents a difficult control problem when accurate end-point position is required. Input shaping by convolving system commands with impulse sequences has been shown to be an effective method of reducing residual vibrations in flexible systems. However, existing shapers have been considered robustness fur only frequency uncertainty. However, this paper presents new multi-hump convolution(CV) input shaper that could accommodate with the simultaneous variation of natural frequency and damping ratio. Comparisons with previously proposed input shapers are presented to illustrate the qualities of the new input shaper. These new shapers will be shown to have better robustness fur the variation of frequency and damping ratio.

Design of Robust Convolution Input Shaper for Variation of Parameter (파라메터 변화에 강인한 Convolution 입력성형기 설계)

  • Park, Un-Hwan;Lee, Jae-Won;Lim, Byoung-Duk
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.127-133
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    • 2001
  • The flexibility of long reach manipulators presents a difficult control problem when accurate end-point position is required. Input shaping by convolving system commands with impulse sequences has been shown to be an effective method of reducing residual vibrations in flexible systems. However, existing shapers has been considered robustness for only frequency uncertainty. However, this paper presents new multi-hump convolution(CV) input shaper that could accommodate with the simultaneous variation of natural frequency and damping ratio. Comparisons with previously proposed input shapers are presented to illustrate the qualities of the new input shaper. These new shapers will be shown to have better robustness for the variation of frequency and damping ratio.

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An Application of the Genetic Algorithm for the Input Shaper on the High Order System (입력 성형기의 고차 시스템 적용을 위한 GA활용)

  • Jeong, Hwang Hun;Yun, So Nam;Lee, Sang Hun
    • Journal of Drive and Control
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    • v.17 no.2
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    • pp.1-8
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    • 2020
  • Recently, industrial systems are becoming quicker and lighter to enable the reduction of energy consumption and increase productivity. So the latest systems are more flexible and rapid than the previous systems. But, with this improvement, another problem has emerged, such as the increase in residual vibration when a system is started or stopped. The input shaper is a command generation method that can remove residual vibration. It can provide a solution to the problem of residual vibration in industrial systems. However, it is difficult to generate the input shaper in high order systems, such as a typical industrial system because the input shaper is induced from the system's vibration characteristics. This study focused on the extra insensitivity shaper that can compensate for the system's modeling error such as input dynamics, and the high order's system affection. A genetic algorithm was deployed to adjust a vibration limitation for the extra insensitivity of the input shaper. A plant is a low damping system that includes one zero and a pole. The fitness functions are an error signal of the system's response with normalized frequency variations. Verification of the suggested system is satisfied by comparison between the zero vibration derivative input shaper's response and the suggested one.

The Vibration Control of Flexible Manipulators using Adaptive Input Shaper (적응 입력다듬기를 이용한 유연한 조작기의 진동제어)

  • 신효필;정영무;강이석
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.2
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    • pp.220-227
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    • 1999
  • The position control accuracy of a robot arm is significantly deteriorated when a long slender arm robot is operated at a high speed. In this case, the robot arm needs to be modeled as a flexible structure, not a rigid one, and its control system needs to be designed with its elastic modes taken into account. In this paper, the vibration control scheme of a one-link flexible manipulator using adaptive input shaper in conjunction with PID controller is presented. The robot consists of a flexible arm manufactured with a thin aluminium plate, an AC servo motor with a harmonic drive for speed reduction, an optical encoder and an accelerometer. On-line identification of the vibration mode is done using the pruned decimation-in-time FFT algorithm to estimate the parameter of the input shaper. Experimental results of the flexible manipulator with a PID controller and input shaper are provided to show the effectiveness of the advocated controllers.

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An Improved Input Shaping Method for Precise Stopping and Residual Vibration Reduction of Cranes (크레인의 정밀한 정지와 잔류진동 억제를 위한 개선된 입력 성형기법)

  • Bae, Gyu-Hyun;Hong, Seong-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.7
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    • pp.717-724
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    • 2013
  • Industrial cranes are indispensable equipment in heavy industry. However, unwanted vibrations in cranes often cause accidents. Input shaping is widely accepted as a useful tool for removing residual vibration in cranes. A unity magnitude zero vibration (UMZV) input shaper is often used for cranes driven by on-off-type motors. However, although a UMZV input shaper minimizes residual vibration, the input shaper cannot prevent the crane from moving slightly further than expected from the original command. This paper describes an improved method of input shaping that can compensate for position inaccuracies, as well as remove the residual vibration of cranes. Experiments were performed to validate the proposed input-shaping method, illustrated through numerical simulations.

Input Shaper Design for Tower Crane in Consideration of Nonlinear Coupled Motions (타워크레인의 비선형 연성 운동 특성을 고려한 입력성형기 설계)

  • Kim, Byung-Gyu;Hong, Seong-Wook
    • Journal of the Korean Society for Precision Engineering
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    • v.26 no.9
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    • pp.88-95
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    • 2009
  • Input shaping has been a very effective control method for reducing payload swing in industrial bridge and gantry cranes. However, conventional input shapers often degrade performance when applied to tower cranes because of the nonlinear coupled dynamics between rotational and radial motions in tower cranes. To alleviate this problem, a new input shaper for tower cranes is developed by means of dynamic modeling, analysis and optimization. This work investigates the tower crane dynamics along with parameters of the tower crane varied. A performance index for input shaper design is proposed so as to reduce the coupled residual vibration of a tower crane using only rotational motion of tower crane. The proposed new input shaper is verified to be effective through simulations and experiments.