Vibration Control of a New Bed Stage System for Ambulance Using MR Dampers

2014 ◽  
Author(s):  
Hee-Dong Chae ◽  
Seung-bok Choi ◽  
Jong-Seok Oh
Keyword(s):  
Mathematical Model ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Design Parameters ◽  
Ride Quality ◽  
Vibration Level ◽  
Mr Dampers ◽  
Secondary Damage ◽  
Stage System ◽  
Magneto Rheological

This paper proposes a new bed stage for patients in ambulance vehicle in order to improve ride quality in term of vibration control. The vibration of patient compartment in ambulance can cause a secondary damage to a patient and a difficulty for a doctor to perform emergency care. The bed stage is to solve vertical, rolling, and pitching vibration in patient compartment of ambulance. Four MR (magneto-rheological) dampers are equipped for vibration isolation of the stage. Firstly, a mathematical model of stage is derived followed by the measurement of vibration level of patient compartment of real ambulance vehicle. Then, the design parameters of bed stage is undertaken via computer simulation. Skyhook, PID and LQR controllers are used for vibration control and their control performances are compared.

A Study on Active Engine Vibration Control by Applying Hydraulic-Piezoelectric Mount

2013 ◽  
Vol 721 ◽  
pp. 501-504
Author(s):  
Hang Xu Yang ◽  
Rui Min Wang ◽  
Dong Mei Liu
Keyword(s):  
Quality Improvement ◽  
Vibration Control ◽  
Vibration Isolation ◽  
Control Method ◽  
Vertical Vibration ◽  
Ride Quality ◽  
Disc Membrane ◽  
Engine Vibration ◽  
Engine Mount ◽  
Active Engine

Study of LMS control method on active engine mount is carried out for ride quality improvement. Take an active engine mount which is based and developed from a hydraulic mount with decoupled disc-membrane as a module, the characteristic of vibration isolation of active engine mount is simulated and analyzed. The results indicated that active engine mount could reduce the vertical vibration effectively with LMS Control method.

Investigation of Annular Gap Size for Optimizing the Dynamic Range of MR Damper Using Comsol Multiphysics Software

2014 ◽  
Vol 606 ◽  
pp. 187-192 ◽  
Author(s):  
Sharmila Fathima ◽  
Asan Gani Abdul Muthalif ◽  
Md. Raisuddin Khan
Keyword(s):  
Vibration Control ◽  
Dynamic Range ◽  
Active Vibration Control ◽  
Comsol Multiphysics ◽  
Gap Size ◽  
Viscous Stress ◽  
Mr Fluid ◽  
Mr Dampers ◽  
Annular Gap ◽  
Magneto Rheological

Magneto-rheological (MR) fluid technology has made it possible to develop reliable, revolutionary vibration control systems for a variety of commercial, medical and military applications. MR fluid shock absorber systems are enabled by remarkably versatile MR fluid technology, which allows the system to respond instantly and controllably to varying levels of vibration or shock with simple, robust designs. This paper presents a parametric study of the MR dampers for semi-active vibration control. The influence of gap size of the damper on the viscous stress of the MR fluid is examined. It is inferred from the study that the viscous stress of the MR fluid for different parameters such as gap size influences the dynamic range of MR fluid dampers.The simulated results depict a maximum viscous stress of 1765.441 N/m2for a gap size of 1.85 mm. The developed dynamic range would allow for smaller size of the device, higher dynamic yield stress and low power consumption. The simulated results using COMSOL multiphysics for the verification of the parametric strategy have been presented. Results of this study shall enhance the design of MR dampers for different control applications.

Variable Damping and Stiffness Vibration Control With Two Magnetorheological Fluid Dampers in Series

2005 ◽  
Author(s):  
Yanqing Liu ◽  
Hiroshi Matsuhisa ◽  
Hideo Utsuno ◽  
Jeong Gyu Park
Keyword(s):  
Vibration Control ◽  
Vibration Isolation ◽  
Degree Of Freedom ◽  
Structural Vibration ◽  
Small Current ◽  
Mr Dampers ◽  
In Series ◽  
Variable Damping ◽  
Fluid Dampers ◽  
Two Degree Of Freedom

Vibration isolation methods that vary damping and stiffness have demonstrated excellent authority over system vibration, thus, potentially making them attractive for many applications. However, conventional devices for controlling variable stiffness are typically complicated and difficult to implement in most applications. To address this issue, a new method is proposed that requires two magnetorheological (MR) fluid dampers placed in series. With this configuration, variable damping and stiffness vibration control is simultaneously achieved by varying a small current to the MR dampers. This paper presents a theoretical and experimental analysis of a two degree-of-freedom system that is controlled by the MR dampers. Five different control schemes involving the variable damping and stiffness are explored. The time and frequency responses of the two degree-of-freedom system to a random input show that combined variable damping and stiffness control provides the best vibration isolation over a frequency range spanning the system’s two structural vibration modes. The experimental results agree well with the theoretical analysis.

PAYLOAD/LAUNCHER VIBRATION ISOLATION: MR DAMPERS MODELING WITH FLUID COMPRESSIBILITY AND INERTIA EFFECTS THROUGH CONTINUITY AND MOMENTUM EQUATIONS

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1534-1541 ◽  
Author(s):  
PIERRICK JEAN ◽  
ROGER OHAYON ◽  
DOMINIQUE LE BIHAN
Keyword(s):  
Vibration Isolation ◽  
Solid Mechanics ◽  
Mr Damper ◽  
Vibration Isolator ◽  
Inertia Effects ◽  
Mr Dampers ◽  
Preliminary Study ◽  
Magneto Rheological ◽  
Theoretical Results ◽  
Fluid Compressibility

During launching, a payload is submitted to large vibrations, which may damage it. To get rid of the problem, a solution would be to put an appropriate vibration isolator at the payload/launcher interface. Thus, a soft Isolating Payload Attach Fitting (IPAF) using Magneto-Rheological (MR) dampers is envisaged. In a pre-design phase for the launcher application, a preliminary study of the behaviour of a commercial MR damper (RD-1005-3) and its use in a 1-dof vibration isolator is carried out. In this paper, we report the MR damper behaviour analysis based on fluid and solid mechanics equations. In particular, we investigate chambers fluid compressibility and inertia effects. Then the damper model is used to evaluate the performance of a MR isolator in terms of equivalent transmissibility in passive mode and using skyhook control. The theoretical results will be soon compared to those from an experimental bench in construction.

scholarly journals A Variable Parameter Ambient Vibration Control Method Based on Quasi-Zero Stiffness in Robotic Drilling Systems

Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 67
Author(s):  
Laixi Zhang ◽  
Chenming Zhao ◽  
Feng Qian ◽  
Jaspreet Singh Dhupia ◽  
Mingliang Wu
Keyword(s):  
Vibration Control ◽  
Vibration Isolation ◽  
Control Method ◽  
Control Strategies ◽  
Equations Of Motion ◽  
Variable Parameter ◽  
Harmonic Balance Method ◽  
Variable Stiffness ◽  
Ambient Vibration ◽  
Robotic Drilling

Vibrations in the aircraft assembly building will affect the precision of the robotic drilling system. A variable stiffness and damping semiactive vibration control mechanism with quasi-zero stiffness characteristics is developed. The quasi-zero stiffness of the mechanism is realized by the parallel connection of four vertically arranged bearing springs and two symmetrical horizontally arranged negative stiffness elements. Firstly, the quasi-zero stiffness parameters of the mechanism at the static equilibrium position are obtained through analysis. Secondly, the harmonic balance method is used to deal with the differential equations of motion. The effects of every parameter on the displacement transmissibility are analyzed, and the variable parameter control strategies are proposed. Finally, the system responses of the passive and semiactive vibration isolation mechanisms to the segmental variable frequency excitations are compared through virtual prototype experiments. The results show that the frequency range of vibration isolation is widened, and the stability of the vibration control system is effectively improved without resonance through the semiactive vibration control method. It is of innovative significance for ambient vibration control in robotic drilling systems.

scholarly journals Simulation Tests of a Cow Milking Machine—Analysis of Design Parameters

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1358
Author(s):  
Ewa Golisz ◽  
Adam Kupczyk ◽  
Maria Majkowska ◽  
Jędrzej Trajer
Keyword(s):  
Mathematical Model ◽  
Simplified Model ◽  
Design Parameters ◽  
Degree Polynomial ◽  
Fourth Degree ◽  
Local Loss ◽  
Linear Drag ◽  
Milking Machine ◽  
Machine Analysis ◽  
The Impact

The objective of this paper was to create a mathematical model of vacuum drops in a form that enables the testing of the impact of design parameters of a milking cluster on the values of vacuum drops in the claw. Simulation tests of the milking cluster were conducted, with the use of a simplified model of vacuum drops in the form of a fourth-degree polynomial. Sensitivity analysis and a simulation of a model with a simplified structure of vacuum drops in the claw were carried out. As a result, the impact of the milking machine’s design parameters on the milking process could be analysed. The results showed that a change in the local loss and linear drag coefficient in the long milk duct will have a lower impact on vacuum drops if a smaller flux of inlet air, a higher head of the air/liquid mix, and a higher diameter of the long milk tube are used.

A Reliability Assessment Model for MR Damper Components within a Smart Structural Control Scheme

2008 ◽  
Vol 56 ◽  
pp. 218-224
Author(s):  
Maguid H.M. Hassan
Keyword(s):  
Structural Control ◽  
Inverse Dynamics ◽  
Mr Damper ◽  
Assessment Model ◽  
Resistance Force ◽  
Mr Dampers ◽  
Control Scheme ◽  
Smart Control ◽  
Control Devices ◽  
Magneto Rheological

Smart control devices have gained a wide interest in the seismic research community in recent years. Such interest is triggered by the fact that these devices are capable of adjusting their characteristics and/or properties in order to counter act adverse effects. Magneto-Rheological (MR) dampers have emerged as one of a range of promising smart control devices, being considered for seismic applications. However, the reliability of such devices, as a component within a smart structural control scheme, still pause a viable question. In this paper, the reliability of MR dampers, employed as devices within a smart structural control system, is investigated. An integrated smart control setup is proposed for that purpose. The system comprises a smart controller, which employs a single MR damper to improve the seismic response of a single-degree-of-freedom system. The smart controller, in addition to, a model of the MR damper, is utilized in estimating the damper resistance force available to the system. On the other hand, an inverse dynamics model is utilized in evaluating the required damper resistance force necessary to maintain a predefined displacement pattern. The required and supplied forces are, then, utilized in evaluating the reliability of the MR damper. This is the first in a series of studies that aim to explore the effect of other smart control techniques such as, neural networks and neuro fuzzy controllers, on the reliability of MR dampers.

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