Semi-active Control of Single Degree of Freedom (SDOF) Systems Using Magnetorheological (MR) Dampers Based on a Modified Inverse Dynamic Model

2018 ◽  
Author(s):  
Xiaochuan Yu ◽  
Haozhan Meng
Keyword(s):  
Dynamic Model ◽  
Active Control ◽  
Degree Of Freedom ◽  
Inverse Dynamic ◽  
Single Degree Of Freedom ◽  
Inverse Dynamic Model ◽  
Mr Dampers ◽  
Single Degree

The Active Control of Forced Vibration Produced by Arbitrary Disturbances

1985 ◽  
Vol 107 (1) ◽  
pp. 33-37 ◽  
Author(s):  
J. S. Burdess ◽  
A. V. Metcalfe
Keyword(s):  
Vibration Control ◽  
Active Control ◽  
Forced Vibration ◽  
Disturbance Observer ◽  
Degree Of Freedom ◽  
Experimental Results ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Impact Forces ◽  
Mass Spring

This paper considers the vibration control of a single degree of freedom mass-spring-damper system when subjected to an arbitrary, unmeasurable disturbance. The idea of a disturbance observer is introduced and it is shown how an estimate of the excitation can be derived and used to generate a control, which reduces the vibration. This control is shown to be robust with respect to the parameters describing the behavior of the system. Experimental results are presented which show the efficacy of the method when the system is excited by periodic, random, and impact forces. Comments are made on the application of the method.

An Inverse Dynamic Model of a Spherical Electrohydraulic Actuator for Use in a Dexterous Mechanical Hand

1995 ◽  
Author(s):  
Shikha Sharma ◽  
Madara M. Ogot
Keyword(s):  
Dynamic Model ◽  
Degree Of Freedom ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Mechanical Hand ◽  
Control Scheme ◽  
Size Constraints ◽  
Pressure Peak ◽  
Traditional Performance ◽  
Electrohydraulic Actuator

Abstract The purpose of this paper is the development of an inverse dynamic model of a two degree of freedom electrohydraulic actuator. The actuator is to be incorporated at the base of each of three fingers of a nine degree of freedom mechanical hand, currently under development. Motion in the proposed actuator is facilitated about intersecting pitch and yaw axes, thus creating spherical actuation. The dynamic model incorporates frictional and hydraulic losses, commonly overlooked sources of energy dissipation. The model is to be used in the control scheme of the mechanical hand and in the optimal synthesis procedure of the actuator. The latter application, briefly described here, takes into account specified motion and torque requirements, pressure, peak input force and size constraints. Particular attention is paid to traditional performance indices, such as mechanical advantage.

scholarly journals A novel inverse dynamic model for a magnetorheological damper based on network inversion

2017 ◽  
Vol 24 (15) ◽  
pp. 3434-3453 ◽  
Author(s):  
MJL Boada ◽  
BL Boada ◽  
V Diaz
Keyword(s):  
Dynamic Model ◽  
Vibration Isolation ◽  
Mr Damper ◽  
Inverse Model ◽  
Magnetorheological Damper ◽  
Hysteretic Behavior ◽  
Inverse Dynamic ◽  
Inverse Dynamic Model ◽  
Mr Dampers ◽  
Highly Nonlinear

Semi-active suspensions based on magnetorheological (MR) dampers are receiving significant attention, especially for control of vibration isolation systems. The nonlinear hysteretic behavior of MR dampers can cause serious problems in controlled systems, such as instability and loss of robustness. Most of the developed controllers determine the desired damping forces which should be produced by the MR damper. Nevertheless, the MR damper behavior can only be controlled in terms of the applied current (or voltage). In addition to this, it is necessary to develop an adequate inverse dynamic model in order to calculate the command current (or voltage) for the MR damper to generate the desired forces as close as possible to the optimal ones. Due to MR dampers being highly nonlinear devices, the inverse dynamics model is difficult to obtain. In this paper, a novel inverse MR damper model based on a network inversion is presented to estimate the necessary current (or voltage) such that the desired force is exerted by the MR damper. The proposed inverse model is validated by carrying out experimental tests. In addition, a comparison of simulated tests with other damper controllers is also presented. Results show the effectiveness of the network inversion for inverse modeling of an MR damper. Thus, the proposed inverse model can act as a damper controller to generate the command current (or voltage) to track the desired damping force.

Optimization of PID controller parameters for active control of single degree of freedom structures

2019 ◽  
Vol 5 (4) ◽  
pp. 130
Author(s):  
Serdar Ulusoy ◽  
Sinan Melih Niğdeli ◽  
Gebrail Bekdaş
Keyword(s):  
Time Delay ◽  
Active Control ◽  
Pid Controller ◽  
Structural Model ◽  
Degree Of Freedom ◽  
Control Force ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Near Fault ◽  
Optimum Parameters

In active control of structures, the parameters of controllers used application must be perfectly tuned. In that case, a good vibration reduction performance can be obtained without a stability problem. During the tuning process, the limit of control force and time delay of controller system must be considered for applicable design. In the study, the optimum parameters of Proportional-Derivative-Integral (PID) type controllers that are proportional gain (K), integral time (Ti) and derivative time (Td) were optimized by using teaching learning-based optimization (TLBO). TLBO is a metaheuristic algorithm imitating the teaching and learning phases of education in classroom. The optimization was done according to the responses of the structure under a directivity pulse of near fault ground motions. In the study, time delay was considered as 20 ms and the optimum parameters of PID controller for a single degree of freedom (SDOF) structural model was found for different control force limits. The performances and feasibility of the method were evaluated by using sets of near fault earthquake records.

A Novel Dynamic Model for Single Degree-of-Freedom Planar Mechanisms Based on Instant Centers

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Raffaele Di Gregorio
Keyword(s):  
Dynamic Model ◽  
Virtual Work ◽  
Degree Of Freedom ◽  
Dynamic Problems ◽  
Planar Mechanisms ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Proposed Model ◽  
External Forces

Many even complex machines employ single degree-of-freedom (single-dof) planar mechanisms. The instantaneous kinematics of planar mechanisms can be fully understood by analyzing where the instant centers (ICs) of the relative motions among mechanism’s links are located. ICs' positions depend only on the mechanism configuration in single-dof planar mechanisms and a number of algorithms that compute their location have been proposed in the literature. Once ICs positions are known, they can be exploited, for instance, to determine the velocity coefficients (VCs) of the mechanism and the virtual work of the external forces applied to mechanism's links. Here, these and other ICs' properties are used to build a novel dynamic model and an algorithm that solves the dynamic problems of single-dof planar mechanisms. Then, the proposed model and algorithm are applied to a case study.

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