• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.1
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• pp.123-130
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• 1996

Due to high payload capacity and high length-to -cross-section ratio requirements, long-reach manipulator systems are expected to exhibit significant structural flexibility. To avoid structural vibrations during operations, various types of input shaping filtering methods have been investigated. A robust notch filtering method and an impulse shaping filtering method were investigated and implemented. In addition, two very different approaches have been developed and compared. One new approach, referred to as a

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1045-1052
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• 2000

In this paper, we propose a method to apply the Input Shaping Technique (IST) to multi-input multi-output (MIMO) systems. In MIMO systems, there is a high possibility of multi-mode residual vibration. The IST filter designed for this multi mode may need a longer time to suppress the residual vibration. Previous works prove that we can shorten the time lag by using negative sequence. This negative sequence, however, causes another problem - it requires excessive control input. In this paper, we provide a remedy to reduce the size of control input by limiting the reference input by limiting the reference input and its derivative. The result of simulations and experiments on a 2 link flexible arm confirmed the effectiveness of the proposed method.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1011-1017
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• 2011

Servo control loops are a core part in the control architecture of machine tools. Servo control loops manage acceleration, velocity and position of all the axes in a machine tool based on commands. The performance of servo control loops sets the basis for quality of production paris and cycle time reduction. First, this paper presents a general control architecture of machine tools and several control schemes in literature, which can be applicable to machine tools control; including Zero Phase Error Tracking Control (ZPETC) and Cross Coupling Control (CCC). After that, modem control strategies to mitigate the problem of high speed machining are reviewed. In high speed machining, high accelerations excite the machine structure up to high frequencies, thereby exciting the structure's modes of vibration. These structural vibrations need to be damped if accurate positioning or trajectory following is required. Input shaping is an attractive option in dealing with structural vibrations. The advantages and drawbacks of using input shaping technique for machine tools are discussed in detail.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.4
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• pp.31-37
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• 2006

In this paper, an experimental study on the robust input shaping for control of the residual vibration of flexible structures has been investigated. Two approaches has been used for the robustness of input shaping: the first method is to increase the number of impulses, and the other includes an EI shaper using vector diagram. The input case designed by the application of the above methods has been applied to a control problem involving residual vibration of a rotating hub with two flexible appendages. It has been found by a series of experiments that the input shaper designed in this paper works well for the residual vibration control of the flexible structure.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.883-888
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• 1999

To obtain high positioning auccuracy for a long, flex bleman Ipulator, residual vibration must be removed from the tip motion. But it is difficult to control the vibration of low frequency. There are open-loop and closed loop methods in the elimination of the residual vibration. We inroduce input shaping technique has been used as a simple open-loop method of controlling the residual vibration of a flexible manipulator. Design of input shaper in the continuous time domain is complicated. This paper presents a new technique that designs input shaper in the z-domain and analyzes input shaping method in the z-domain. This technique is simple and easy to design input shaper.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.130.5-130
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• 2001

This paper presents a discrete-time sliding mode control method for linear time-invariant systems with matched uncertainties. In this paper, we suggest a method of adding a command generator using input shaping filter to a discrete-time sliding mode controller. We design the number of steps required to reach the sliding layer and the magnitude of a control input, respectively using the shaping filter. Therefore we can minimize the excitation of the resonance mode and increase the tracking performance of a system. Simulation results are included to show its effectiveness.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.2
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• pp.83-89
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• 2008

This paper presents the dynamic analysis and input shaping control of a positioning stage. Vibration characteristics of the positioning stage are affected not only by the structural dynamics but also by the servo actuators that consist of the mechanism; driving motor and controller. This paper proposes an integrated dynamic model to accommodate both the structural dynamics and the servo actuators. Theoretical modal analysis with a commercial finite element code is carried out to investigate the dynamic characteristics of the experimental positioning stage. Experiments are performed to validate the theoretical modal analysis and estimate the equivalent stiffness due to the servo actuators. This paper deals with an input shaping scheme to suppress vibration of the positioning stage. Input shapers are systematically implemented for the positioning stage in consideration of its dynamics. The effects of servo control gain are also investigated. The experiments show that input shaping effectively removes residual vibrations and then improves the performance of positioning stage.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1087-1090
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• 1996

The objective of this paper is to present a new input torque shaping method for slewing and vibration suppression of flexible structure based on Fourier series expansion. Vibration energy of the structure with shaped control input is investigated with respect to the shaping parameter of the reference torque, maneuver time and the number of trigonometric functions to be included in the series. Analytic expressions of the performance indices and their derivatives are derived in the modal coordinates. Numerical results show the effectiveness of the proposed approach to design the open-loop control law that modifies the shape of input torque for simultaneous slewing and vibration suppression.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.53-59
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• 1999

Input shaping technique has been used as a simple method of controlling vibration. With the conventional methods previously proposed by several authors, the frequency range that shows a good performance is restricted. When the designed frequency being different from the natural frequency of a system, the performance of control degrades remarkably. This paper introduced a new technique that uses digital IIR filter to control vibration. This technique has robustness for changing of parameter. In order to prove this we applied input shaping method to 2 axial overhead crane.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.169-175
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• 2009

This paper presents motion control of the Inchworm composed of the piezoelectric actuators and mechanical elements. Piezoelectric actuator shows nonlinear response characteristics including hysteresis due to the ferroelectric characteristics. This paper proposes feedback control scheme to improve the ability of tracking response to complex input signal and suppress the phenomenon of hysteresis using the sliding mode control technique with the integrator. The sliding mode control system has the limit to minimize both the settle time and overshoot. For making up this limit, this paper also suggests input shaping technique suitable to the inchworm control system.