Analysis and Strategy for Superharmonics With Semiactive Suspension Control Systems

2007 ◽  
Vol 129 (6) ◽  
pp. 795-803 ◽  
Author(s):  
Xubin Song ◽  
Mehdi Ahmadian ◽  
Steve Southward
Keyword(s):  
Adaptive Control ◽  
Control Systems ◽  
Adaptive Algorithm ◽  
Vibration Suppression ◽  
Negative Impact ◽  
Mr Damper ◽  
System Stability ◽  
Structural Vibration ◽  
Vehicle Suspensions ◽  
Seat Suspension

This paper focuses on an experimental implementation of a semiactive seat suspension using magnetorheological (MR) dampers. We first introduce the nonlinear dynamics phenomena induced by skyhook control. Skyhook control has been widely applied to applications ranging from structural vibration suppression to commercialized vehicle suspensions. Unfortunately, skyhook control generates superharmonic dynamics; yet, this issue has not been clearly addressed in such vibration control systems. This paper will attempt to explain how superharmonics are created with skyhook controls through analysis of test data. Furthermore, a nonlinear model-based adaptive control algorithm is developed and evaluated for reducing the negative impact of the superharmonics. Based on an empirical MR damper model, the adaptive algorithm is expanded mathematically, and the system stability is discussed. Then in the following sections, this paper describes implementation procedures such as modeling simplification and validation, and testing results. Through the laboratory testing, the adaptive suspension is compared to two passive suspensions: hard-damping (stiff) suspension with a maximum current of 1A to the MR damper and low-damping (soft) suspension with a low current of 0A, while broadband random excitations are applied with respect to the seat suspension resonant frequency in order to test the adaptability of the adaptive control. In two separate studies, both mass and spring rate are assumed known and unknown in order to investigate the capability of the adaptive algorithm with the simplified model. Finally, the comparison of test results is presented to show the effectiveness and feasibility of the proposed adaptive algorithm to eliminate the superharmonics from the MR seat suspension response.

Superharmonics-Free Adaptive Semiactive Magneto-Rheological Suspension

2005 ◽  
Author(s):  
Xubin Song ◽  
Mehdi Ahmadian ◽  
Steve Southfield ◽  
Lane Miller
Keyword(s):  
Adaptive Control ◽  
Adaptive Algorithm ◽  
Vibration Suppression ◽  
Mr Damper ◽  
Adaptive Controller ◽  
System Stability ◽  
Structural Vibration ◽  
Vehicle Suspensions ◽  
Seat Suspension ◽  
Magneto Rheological

This paper focuses on laboratory implementation of a semiactive seat suspension with application of magneto-rheological (MR) dampers. We firstly introduce the nonlinear dynamics phenomena induced with the skyhook control that is now widely applied from structural vibration suppression to commercialized vehicle suspensions. However, superharmonic dynamics has not been clearly addressed in such vibration control systems. This paper tries to explain how superharmonics are created with skyhook controls through testing data analysis. Furthermore, in order to avoid this dynamics issue, this study implements a nonlinear model-based adaptive control into this MR damper based seat suspension. Based on a nonparametric MR damper model, the adaptive algorithm is expanded mathematically, and the system stability is discussed. Then in the following sections, this paper describes implementation procedures such as modeling simplification and validation, and testing results. Through the laboratory testing, the adaptive suspension is compared to two passive suspensions: hard-damping (stiff) suspension with max current of 1A to the MR damper, and low-damping (soft) suspension with minimum of 0A, while broadband random excitations are applied with respect to the seat suspension resonant frequency in order to test the adaptability of the adaptive control. Furthermore, mass and spring rate are assumed known and unknown for this adaptive controller to investigate the capability of this algorithm with the simplified model, respectively. Finally the comparison of testing results is presented to show the effectiveness and feasibility of the proposed adaptive algorithm to eliminate the superharmonics from the MR seat suspension.

Anti-Windup LPV Control Design of MR Dampers for Structural Vibration Suppression

2011 ◽  
Author(s):  
Mona Meisami-Azad ◽  
Farzad A. Shirazi ◽  
Karolos M. Grigoriadis
Keyword(s):  
Control Strategy ◽  
Vibration Suppression ◽  
Actuator Saturation ◽  
Control Design ◽  
Mr Damper ◽  
Structural Vibration ◽  
Engineering Structures ◽  
Control Effort ◽  
Mr Dampers ◽  
Lpv Control

Magneto-rheological (MR) dampers that belong to the family of semi-active devices are widely used for vibration attenuation in space and civil engineering structures. In this paper, we study the use of MR dampers for seismic protection of a model two-story structure. A modified Bingham model of the MR damper is considered for linear parameter varying (LPV) modeling and control of the system. The main contribution of the paper is the design and experimental validation of an LPV anti-windup compensator to tackle the effect of actuator saturation on control design performance. The designed LPV anti-windup control scheme is advantageous from the implementation standpoint because it can be considered as an addition to the existing control system. Experimental results demonstrate the effective vibration suppression of the structure in the presence of the seismic excitation inputs by utilizing an LPV control strategy. An inner/outer loop control strategy is further developed and implemented considering the actuator saturation effect to reduce the control effort and saving the MR damper power consumption.

Vibration Suppression by Controlling an MR Damper

1999 ◽  
Vol 13 (14n16) ◽  
pp. 2221-2228 ◽  
Author(s):  
Doyoung Jeon ◽  
Chanho Park ◽  
Kiyang Park
Keyword(s):  
Mechanical Properties ◽  
Time Delay ◽  
Response Time ◽  
Vibration Control ◽  
Control Systems ◽  
Vibration Suppression ◽  
Mr Damper ◽  
Mr Fluid ◽  
Mr Fluids

For the semiactive vibration control, a variable damper and proper control systems are essential. In this research a controllable damper was designed using the MR fluids and its mechanical properties such as damping constant and response time were measured. Since the response time of the MR damper was much longer than nominal MR fluid response time, the time delay of the damper should be considered in the design of controllers. It is shown that the advanced on/off vibration control which includes the damper time delay performs more effectively than the conventional one.

Design and Analysis of Adaptive Control Systems Over Wireless Networks

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Ali Albattat ◽  
Benjamin Gruenwald ◽  
Tansel Yucelen
Keyword(s):  
Wireless Networks ◽  
Adaptive Control ◽  
Control Systems ◽  
Data Exchange ◽  
Controller Design ◽  
Adaptive Controller ◽  
System Stability ◽  
Design Parameters ◽  
Adaptive Control Systems ◽  
Command Following

In this paper, we study the design and analysis of adaptive control systems over wireless networks using event-triggering control theory. The proposed event-triggered adaptive control methodology schedules the data exchange dependent upon errors exceeding user-defined thresholds to reduce wireless network utilization and guarantees system stability and command following performance in the presence of system uncertainties. Specifically, we analyze stability and boundedness of the overall closed-loop dynamical system, characterize the effect of user-defined thresholds and adaptive controller design parameters to the system performance, and discuss conditions to make the resulting command following performance error sufficiently small. An illustrative numerical example is provided to demonstrate the efficacy of the proposed approach.

Seismic Response Controlled Structure With Semi-Active Mass-Damper

2008 ◽  
Author(s):  
Fan Yang ◽  
Ramin Sedaghati ◽  
Ebrahim Esmailzadeh
Keyword(s):  
Vibration Suppression ◽  
Mr Damper ◽  
Friction Model ◽  
Structural Vibration ◽  
Active Mass ◽  
Lugre Friction Model ◽  
Mass Damper ◽  
Active Mass Damper ◽  
Controlled Structure ◽  
Magneto Rheological

The structural vibration suppression using active and semi-active mass damper is investigated. The controller for full-active controlled mass dampers is designed using the H2/LQG method. Magneto-Rheological (MR) damper is used to design the semi-active controlled mass damper. The inverse MR-damper model is developed on the base of an improved LuGre friction model. It combined with the proposed H2/LQG controller to control the input current of the MR-damper to suppress the structural vibration efficiently. The illustrated examples are presented to compare the vibration suppression effectiveness of semi-active mass damper with MR-damper using the proposed controller with those reported in literatures in order to illustrate the validity of the proposed methodology.

Optimal Vibration Suppression of Structures Under Random Base Excitation Using Semi-Active Mass Damper

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
F. Yang ◽  
E. Esmailzadeh ◽  
R. Sedaghati
Keyword(s):  
Vibration Suppression ◽  
Mr Damper ◽  
Friction Model ◽  
Structural Vibration ◽  
Linear Quadratic ◽  
Active Mass ◽  
Lugre Friction Model ◽  
Mass Damper ◽  
Active Mass Damper ◽  
Control Methodology

The vibration suppression of structures using a semi-active mass damper is investigated in this study. A magnetorheological (MR)-damper is utilized to design the semi-actively controlled mass damper. The inverse MR-damper model is developed on the basis of an improved LuGre friction model, and combined with a designed H2/Linear-Quadratic-Gaussian (H2/LQG) controller, in order to control the command current of the MR-damper to suppress structural vibration levels effectively. Illustrated examples are considered to investigate the vibration suppression effectiveness of a semi-active mass damper with a MR-damper, using the developed control methodology. The simulation results were compared with those reported in literature in order to validate the presented methodology.

A New Perspective for Time Delayed Control Systems With Application to Vibration Suppression

2002 ◽  
Author(s):  
Rifat Sipahi ◽  
Nejat Olgac
Keyword(s):  
Time Delay ◽  
Control Systems ◽  
Vibration Suppression ◽  
Linear Time ◽  
Direct Method ◽  
Interesting Property ◽  
System Stability ◽  
Delayed Systems ◽  
Linear Time Invariant ◽  
The Stability

Most control systems are contaminated with some level of time delay. Whether it appears due to the inherent system dynamics or because of the sensory feedback, the delay has to be resolved regarding the system stability. We explain an unprecedented and fundamental treatment of time delay in a general class of linear time invariant systems (LTI) following a strategy, which we call the ‘Direct Method’. The strengths of the method lie in recognizing two interesting and novel features, which are typical for this class of systems. These features enable a structured strategy to be formed for analyzing the stability of LTI-TDS (Time Delayed Systems). Vibration control settings are not immune from time delay effects. We present a case study on active control of vibration using linear full state feedback. We then apply the Direct Method on this structure to display the stability outlook along the axis of delay. There appears an interesting property, which is related to the determination of the imaginary (i.e. marginally stable) roots of LTI-TDS. We state a general lemma and proof on this point.

Simulation Study of Adaptive Magneto-Rheological Seat Suspension

2004 ◽  
Author(s):  
Xubin Song ◽  
Mehdi Ahmadian ◽  
Steve Southward ◽  
Lane Miller
Keyword(s):  
Simulation Study ◽  
Adaptive Algorithm ◽  
Simulation Analysis ◽  
Mr Damper ◽  
Adaptive Controller ◽  
Step Size ◽  
Seat Suspension ◽  
Model Based ◽  
Magneto Rheological ◽  
Adaptive Suspension

This paper describes the details of the simulation analysis of a nonlinear model-based adaptive suspension control system[1, 2]. The numerical aspect of the simulation study of a seat suspension with application of magneto-rheological dampers will be presented. Magneto-rheological (MR) dampers have strong nonlinearities such as bi-linearity, hysteresis, and saturation related to magnetism, which can be represented by appropriate mathematic functions, respectively. Thus the model-based adaptive algorithm becomes complicated because of involvement of MR damper models. One objective of this study is to investigate the effect of MR damper model simplifications on the adaptive suspension performance. Furthermore, simulation is also applied to do parametric study of adaptive algorithm parameters such as filtering and step size. The simulation results compare the proposed adaptive controller with passive dampers to validate not only its effectiveness but also obtain some guidance information for its experimental implementation.

Sign in / Sign up

Export Citation Format

Share Document