On the Design of Magnetic Suspension Systems

1990 ◽  
Author(s):  
A. Sinha
Keyword(s):  
Nonlinear Control ◽  
Initial Conditions ◽  
Dynamic Performance ◽  
Magnetic Suspension ◽  
Linear Feedback ◽  
Control Laws ◽  
Suspension Systems ◽  
Mass Damper ◽  
Linear Spring ◽  
Feedback Laws

First, the dynamic performance of magnetic suspension systems (Figures 1–3), which are designed on the basis of linear feedback laws, are examined. Then, nonlinear control laws are developed to make the dynamics of a suspension system to be exactly that of a linear spring-mass-damper system. It is found that such control laws are not defined for all initial conditions of the supported mass. Lastly, it is shown that it is possible to achieve a true spring-mass-damper behavior for all initial conditions by using two electromagnets, but operating only one at a time.

A novel tuned mass-conical spring system for passive vibration control of a variable mass structure

2021 ◽  
pp. 107754632110004
Author(s):  
Sanjukta Chakraborty ◽  
Aparna (Dey) Ghosh ◽  
Samit Ray-Chaudhuri
Keyword(s):  
Variable Mass ◽  
Design Procedure ◽  
Time History ◽  
Tuned Mass Damper ◽  
Water Tank ◽  
Mass System ◽  
Mass Damper ◽  
Linear Spring ◽  
Spring System ◽  
Elevated Water

This article presents the design of a tuned mass damper with a conical spring to enable tuning to the natural frequency of the system at multiple values, as may be convenient in case of a system with fluctuations in the mass. The principle and design procedure of the conical spring in the context of a varying mass system are presented. A passive feedback control mechanism based on a simple pulley-mass system is devised to cater to the multi-tuning requirements. A design example of an elevated water tank with fluctuating water content, subjected to ground excitation, is considered to numerically illustrate the efficiency of such a tuned mass damper associated with the conical spring. The conical spring is designed based on the tuning requirements at different mass conditions of the elevated water tank by satisfying the allowable load bearing capacity of the spring. Comparisons are made with the conventional passive tuned mass damper with a linear spring tuned to the full tank condition. Results from time history analysis reveal that the conical spring-tuned mass damper can be successfully designed to remain tuned and thereby achieve significant response reductions under stiffening conditions of the primary structure, whereas the linear spring-tuned mass damper suffers performance degradation because of detuning, whenever there is any fluctuation in the system mass.

scholarly journals Analysis of the stability of multi-mode systems with approximating nonlinear control laws

2021 ◽  
Vol 872 (1) ◽  
pp. 012010
Author(s):  
E A Shakhray ◽  
E V Lubentsova ◽  
V F Lubentsov ◽  
M V Meflekh
Keyword(s):  
Nonlinear Control ◽  
Control Laws ◽  
The Stability ◽  
Multi Mode

scholarly journals Levitation Methods for Use in the Hyperloop High-Speed Transportation System

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4190 ◽  
Author(s):  
Eric Chaidez ◽  
Shankar P. Bhattacharyya ◽  
Adonios N. Karpetis
Keyword(s):  
Speed Of Sound ◽  
High Speed ◽  
System Size ◽  
Magnetic Suspension ◽  
Air Bearings ◽  
Commercial Aviation ◽  
Simple Theories ◽  
Suspension Systems ◽  
Air Resistance ◽  
High Speed Trains

The Hyperloop system offers the promise of transportation over distances of 1000 km or more, at speeds approaching the speed of sound, without the complexity and cost of high-speed trains or commercial aviation. Two crucial technological issues must be addressed before a practical system can become operational: air resistance, and contact/levitation friction must both be minimized in order to minimize power requirements and system size. The present work addresses the second issue by estimating the power requirements for each of the three major modes of Hyperloop operation: rolling wheels, sliding air bearings, and levitating magnetic suspension systems. The salient features of each approach are examined using simple theories and a comparison is made of power consumption necessary in each case.

scholarly journals Accurate Motion Control of a Pneumatic Linear Peristaltic Actuator

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 63 ◽  
Author(s):  
João Falcão Carneiro ◽  
João Bravo Pinto ◽  
Fernando Gomes de Almeida
Keyword(s):  
Closed Loop ◽  
Low Cost ◽  
Dynamic Performance ◽  
Control Law ◽  
Control Loop ◽  
Control Laws ◽  
Loop Control ◽  
Error Band ◽  
Short Service Life ◽  
High Mechanical Stress

Pneumatic linear peristaltic actuators can offer some potential advantages when compared with conventional ones. The low cost, virtually unlimited stroke and easy implementation of curved motion profiles are among those benefits. On the downside, these actuators suffer high mechanical stress that can lead to short service life and increased leakage among chambers during the actuator lifetime. One way to cope with this problem is to impose the force—instead of the displacement—between rollers, as this has been shown to improve the endurance of the hose while reducing leakage during the actuator lifetime. This paper presents closed control loop results using such a setup. Previous studies with linear peristaltic actuators have revealed that, although it is possible to reach zero steady state error to constant references with closed loop control, the dynamic response obtained is very slow. This paper is mainly focused on this topic, namely on the development of several control laws to improve the dynamic performance of the system while avoiding limit cycles. The new developed control law leads to an average time of 1.67 s to reach a 0.1 mm error band in an experiment consisting of a series of 16 steps ranging from 0.02 to 0.32 m in amplitude.

Dynamic performance investigations of a turbojet engine using a cross-application visual oriented platform

2008 ◽  
Vol 112 (1129) ◽  
pp. 161-169 ◽  
Author(s):  
K. G. Kyprianidis ◽  
A. I. Kalfas
Keyword(s):  
Gas Turbine ◽  
Initial Conditions ◽  
Dynamic Performance ◽  
Simulation Models ◽  
Simulation Software ◽  
Performance Models ◽  
Programming Environments ◽  
Performance Simulation ◽  
Spreadsheet Program ◽  
Turbojet Engine

Abstract This paper presents the development of visual oriented tools for the dynamic performance simulation of a turbojet engine using a cross-application approach. In particular, the study focuses on the feasibility of developing simulation models using different programming environments and linking them together using a popular spreadsheet program. As a result of this effort, a low fidelity cycle program has been created, capable of being integrated with other performance models. The amount of laboratory sessions required for student training during an educational procedure, for example for a course in gas turbine performance simulation, is greatly reduced due to the familiarity of most students with the spreadsheet software. The model results have been validated using commercially available gas turbine simulation software and experimental data from open literature. The most important finding of this study is the capability of the program to link to aircraft performance models and predict the transient working line of the engine for various initial conditions in order to dynamically simulate flight phases including take-off and landing.

Nonlinear Control for Dual Objective Active Suspension Systems

2017 ◽  
Vol 18 (3) ◽  
pp. 656-665 ◽  
Author(s):  
Vaijayanti S. Deshpande ◽  
Pramod D. Shendge ◽  
Shrivijay B. Phadke
Keyword(s):  
Nonlinear Control ◽  
Active Suspension ◽  
Suspension Systems ◽  
Active Suspension Systems
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