Papers by Keyword: Vibration Suppression

Abstract: The vibration suppression of Timoshenko beams, subject to the random excitation, using the Distributed Tuned Mass Damper (DTMD) technology has been investigated in this study. The governing differential equations of motion of the Timoshenko beam with the attached DTMD system have been derived using extended Hamilton's principle, and solved utilizing the Finite Element Method (FEM). Comparing with the traditional TMD or DTMD design methodologies, in this study the design is focused on the attached mass (es) of the DTMD system under predefined stiffness (es) and damping factor (s). The validity of the established design methodologies have been verified through illustrated examples.

Abstract: The paper deals with the problem of suppressing vibration of the arm of Motoman SSF200 robot within the frame of the technological process. Based on an overview of literature, a semi-active vibration control system was selected and a double ended magnetorheological damper (MR) was designed. After testing the acceleration of the robot arm in milling operation without the MR damper, the device was employed and the acceleration of the robot arm in four operation modes was experimentally tested.The conducted research has proved that the double ended MR damper can be practically applied for suppressing the vibration of the robot arm. The higher power to the electromagnet of the MR damper is exposed, the better vibration suppression is. This means that by changing the strength of current, the technological process of the robot arm is under control. Thus, control over the technological process is simplified when the physical characteristics of the milled material, milled tool or operation vary.

Abstract: Wind-induced vibration can affect the safety of power transmission tower. Vibration suppression of the high-rise tower is of concern in engineering. Vibration of the tower is mostly the first-order bending modal and this vibration can be suppressed by the tuned mass damper (TMD). This paper developed a TMD vibration damping device using eddy current damper constituted by magnetic steel installed in the vibration mass and fixed copper plate. It is characterized by simple structure and easy installation, and is suitable for wind-induced damage prevention of transmission tower. Focusing on a quadruple-circuit on the same steel tube tower, a vibration reduction test on a real-scale tower conducted. The result shows that the damping ratio of the tower after installed with the TMD device will increase about 3%. The actual test result verifies the effectiveness of the eddy current TMD device.

Abstract: Magnetorheological elastomer still becomes interested topics among researchers since the rheological properties can be controlled by applying external magnetic field by means of adjustable modulus of elasticity. In this paper, the current application of MRE and related patents will be discussed. Potential application of MRE focused on three main areas. The first is explanation on MRE implementation in vibration cancellation mainly in vehicle system such as active vibration suppression and variable impedance sound absorber. The second explanationfocuses on its potential application on medical devices such as prosthetic device. The third section describes future possible application of MRE based on its tunable properties.Finally, the concluding remarks can be generally stated that MRE still has wide range smart device development and promising more valuable product.

Abstract: The overhung spindle system is studied as the object after remanufacturing, the spindle simplified cantilever and the mathematical model was established based on the simplified equivalent device. The simulation analysis of the dual cantilever was carried out by using ANSYS.The vibration mode and inherent frequency of the cantilever, the deformation caused by the applied loads was given in this paper.It is designed by the linear quadratic optimal control of two state regulator through analyzing the vibration form and loading condition,use of independent modal control algorithm based on the detection of the position feedback control,It is inhibited effectively when a cantilever beam subjected to external transient pulse disturbance caused by two order and higher order system mode vibration,and using the Matlab software programming for active vibration control effects simulation.In addition.Matlab software gave the image result of response of vibration system.Both the brief solution program and the accurate image data which corresponded with vibration theory showed the feasibility and superiority during solving these responses of the spindle vibration system after remanufacturing.Thereby,this research provided an easy and effective method to solve the response of general mechanical vibration system.

Abstract: The delayed dynamical vibration absorber is applied to suppress the vibration of the torsional vibration system. The governing equations of the two degree of freedom vibrating system consisting of crankshaft and delayed dynamical vibration absorber are obtained. The physical parameters of the dynamical vibration absorber for the passive control system are optimum designed. The frequency of anti-resonant point is located at the midpoint between two resonant points, and the optimized amplitude frequency response curve is relatively flat near the anti-resonant point. The control parameters of gain and time delay are optimum designed in the active control system. The minimum amplitude of crankshaft is selected as the optimization objective. The genetic algorithm is used to optimize these control parameters. The optimized delayed dynamical vibration absorber has achieved good performance of vibration suppression within a wide frequency band of external excitation.

Abstract: Vibration suppression is a major problem in various domains, with applications ranging from medical devices to aerospace engineering. Several methods for suppressing vibrations have been proposed, but very few address this issue from the fractional calculus perspective. The emerging new fractional order controllers have the ability to meet more design specifications at the same time, behaving robustly against modeling uncertainties, external disturbances, etc. In this paper, a new tuning method for fractional order PD^µ controller is proposed in which the design directly addresses the problem of suppressing resonance frequency vibrations. The case study consists in an unloaded smart beam. The simulation results, considering an additional situation of the loaded smart beam, show that the proposed method is simple and leads to a robust closed loop behavior.

Abstract: The objective of this research work is to model a dynamical system that can undergo flexible deformations along with the general rigid-body motions. For the system to be able to provide precise outputs when excited by an input, the modal shapes need to be examined and a suitable control strategy is required to make the manipulator adapt to a particular use. The input shaping parameters have been analyzed for specific modes of vibrations. The model uses a Gaussian input torque and power spectral density plots are developed with suitable sampling frequency to show the variation of PSD for the modes of vibration under consideration, thereby providing an insight into the shaping parameters of the Gaussian input.

Abstract: Introducing the particle damping technology into the gear transmission will effectively reduce the vibration during gear engagement, especially suitable for high temperature, oil-lubricating environment for the gear transmission system. In the real working situation, centrifugal load will make the particle at one end away from the rotation center. The vibration suppression of particle damping in the gear transmission is studied through experimental method. The effect of rotation speed and particle filling rate on vibration suppression of particle damping is analyzed in gear transmission. The result will provide exact theory basis and design principle for the vibration suppression of gear transmission.

Abstract: To solve the problem of space flexible manipulator to track the desired trajectory, the robust control is proposed using a NN function to approach the comprehensive modeling errors. The adaptive feedback control for vibration suppression is designed of the system with unknown parameters. The adaptive laws are obtained by Lyapunov method without any prior knowledge about the bounds of unknown parameters. Finally, the numerical simulation is carried out, which proves the controller proposed is feasible and effective.