Vibration Reduction and Isolation by On-Off Control of Friction Force at Spring Support

1997 ◽  
Author(s):  
Hideya Yamaguchi ◽  
Masahito Yashima ◽  
Yoshinori Hirayama
Keyword(s):  
Energy Dissipation ◽  
Control Theory ◽  
Numerical Simulations ◽  
Friction Force ◽  
Transient Response ◽  
Vibration Reduction ◽  
Variable Structure ◽  
Variable Structure Systems ◽  
Switching Law ◽  
Spring Support

Abstract This paper presents a new method of on-off control for the spring support to reduce and isolate vibration transmitted to machines or structures. The procedure utilizes the auxiliary spring whose end is designed to control the clamping friction force with the brake mechanism. The clamping friction force is varied according to the switching law that is deduced from the variable structure systems (VSS) control theory taking into account the energy dissipation due to friction. The experiments and numerical simulations confirmed the effectiveness of the proposed method by investigating the transient response and the displacement transmissibility.

Study On Energy Dissipation Mechanism of an Impact Damper System

2022 ◽  
Author(s):  
Vinayaravi R ◽  
Jayaraj Kochupillai ◽  
Kumaresan D ◽  
Asraff A. K
Keyword(s):  
Energy Dissipation ◽  
Numerical Simulations ◽  
Fundamental Frequency ◽  
Low Frequency ◽  
High Amplitude ◽  
Lagrangian Multiplier ◽  
Impact Damper ◽  
Contact Algorithm ◽  
Dissipation Of Energy ◽  
Excitation Time

Abstract The objective of this paper is to investigate how higher damping is achieved by energy dissipation as high-frequency vibration due to the addition of impact mass. In an impact damper system, collision between primary and impact masses cause an exchange of momentum resulting in dissipation of energy. A numerical model is developed to study the dynamic behaviour of an impact damper system using a MDOF system with Augmented Lagrangian Multiplier contact algorithm. Mathematical modelling and numerical simulations are carried out using ANSYS FEA package. Studies are carried out for various mass ratios subjecting the system to low-frequency high amplitude excitation. Time responses obtained from numerical simulations at fundamental mode when the system is excited in the vicinity of its fundamental frequency are validated by comparing with experimental results. Magnification factor evaluated from numerical simulation results is comparable with those obtained from experimental data. The transient response obtained from numerical simulations is used to study the behaviour of first three modes of the system excited in vicinity of its fundamental frequency. It is inferred that dissipation of energy is a main reason for achieving higher damping for an impact damper system in addition to being transformed to heat, sound, and/or those required to deform a body.

Decentralized Adaptive Control of a Directly Driven Hydraulic Manipulator: Part 1: Theory

1995 ◽  
Vol 209 (3) ◽  
pp. 191-196 ◽  
Author(s):  
K A Edge ◽  
F Gomes de Almeida
Keyword(s):  
Adaptive Control ◽  
Variable Structure ◽  
System Stability ◽  
Design Parameters ◽  
Variable Structure Systems ◽  
Model Following ◽  
Reference Type ◽  
Control Objective ◽  
Manipulator Design ◽  
Following Error

A new approach to adaptive control of manipulators is presented in this paper. The proposed controller for each individual axis is of the model reference type, designed through the use of variable structure systems theory. A novel feature of the controller is the introduction of a series-parallel model of the model-following error. The use of this model ensures system stability even if the manipulator design parameters or payload bounds are exceeded. Chattering of the system, associated with variable structure systems, is eliminated by arranging for the control objective to be physically achievable.

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