The Use of Damping Based Semi-Active Control Algorithms in the Mechanical Smart-Spring System

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Wander Gustavo Rocha Vieira ◽  
Fred Nitzsche ◽  
Carlos De Marqui
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Vibration Reduction ◽  
Flow Analysis ◽  
Coupled Systems ◽  
Control Technique ◽  
Control Algorithms ◽  
Control Techniques ◽  
Spring Mechanism

In recent decades, semi-active control strategies have been investigated for vibration reduction. In general, these techniques provide enhanced control performance when compared to traditional passive techniques and lower energy consumption if compared to active control techniques. In semi-active concepts, vibration attenuation is achieved by modulating inertial, stiffness, or damping properties of a dynamic system. The smart spring is a mechanical device originally employed for the effective modulation of its stiffness through the use of semi-active control strategies. This device has been successfully tested to damp aeroelastic oscillations of fixed and rotary wings. In this paper, the modeling of the smart spring mechanism is presented and two semi-active control algorithms are employed to promote vibration reduction through enhanced damping effects. The first control technique is the smart-spring resetting (SSR), which resembles resetting control techniques developed for vibration reduction of civil structures as well as the piezoelectric synchronized switch damping on short (SSDS) technique. The second control algorithm is referred to as the smart-spring inversion (SSI), which presents some similarities with the synchronized switch damping (SSD) on inductor technique previously presented in the literature of electromechanically coupled systems. The effects of the SSR and SSI control algorithms on the free and forced responses of the smart-spring are investigated in time and frequency domains. An energy flow analysis is also presented in order to explain the enhanced damping behavior when the SSI control algorithm is employed.

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

Active Control of Elastodynamic Vibrations of a Flexible Mechanism With Piezoelectric Actuator

1999 ◽  
Author(s):  
Ching-I Chen
Keyword(s):  
Control Theory ◽  
Active Control ◽  
Piezoelectric Actuator ◽  
Control Strategies ◽  
Piezoelectric Actuators ◽  
Structural Vibration ◽  
Control Technique ◽  
Vibration Modes ◽  
Time Sharing ◽  
Transient Dynamic

Abstract This study focused on the application of active vibration control strategies for flexible moving structures which degrade into transient dynamic vibration problem. These control strategies are based primarily on modal control methods in which the flexible moving structures are controlled by reducing their dominant vibration modes. This work numerically investigated active control of the elastodynamic response of a four-bar mechanical system, using a piezoelectric actuator. A controller based on the modified independent modal space control theory was also utilized. This control theory produced overall excellent performance in terms of achieving the desired closed-loop structural damping. The merits of this technique include its ability to manage the spill-over effect, i.e. eliminate the magnitude of vibrations associated with uncontrolled modes, using only a few selected modes for control. This control was accomplished using a time sharing technique, which reduces the number of piezoelectric actuators required to control a large number of vibration modes. Furthermore, this algorithm implements a procedure for determining the optimal locations for the piezoelectric actuators. The dynamics of a steel four-bar linkage was selected with a flexible coupler separated by six elements and one piezoelectric actuator was used in the numerical simulation. The optimal actuator position was located at the third element from the right to the left. Results in this study demonstrated that a highly desired the structural vibration damping could be achieved. This control technique can be applied to transient dynamic systems.

scholarly journals Numerical Test of Several Controllers for Underactuated Underwater Vehicles

2020 ◽  
Vol 10 (22) ◽  
pp. 8292
Author(s):  
Przemyslaw Herman
Keyword(s):  
Control Algorithm ◽  
Control Strategies ◽  
Numerical Test ◽  
Underwater Vehicle ◽  
Underwater Vehicles ◽  
Control Algorithms ◽  
Dynamics Model ◽  
Numerical Tests ◽  
Control Schemes ◽  
Testing Algorithm

This work is devoted to preliminary numerical tests of selected control strategies of underwater vehicles in the absence of a force applied to the side. The aim was to test the effectiveness of control algorithms for underwater vehicle models considered to be underactuated. Initially, the testing algorithm is used to obtain some information about the dynamics model. Several well-known control schemes for two underwater vehicles for two desired trajectories were selected and tested. The simulations made for the planar 3-DOF model of two underwater vehicles show the performance that can be achieved with each control algorithm according to the assumptions made.

scholarly journals Comparison of Contact Force Control Strategies on Different Robot Arm Types

2010 ◽  
Author(s):  
Hu¨seyin Yaltirik ◽  
A. Kerim Kar ◽  
Bu¨lent Ekici
Keyword(s):  
Force Control ◽  
Control Algorithm ◽  
Control Strategies ◽  
Control Algorithms ◽  
Robot Arm ◽  
Interaction Forces ◽  
Static Contact ◽  
Contact Tasks ◽  
Control Interaction ◽  
Contact Force Control

Nowadays robots are used in various areas. There are extremely important applications where the robot arm tip comes in contact with the environment or an object. During controlling an object, static or in motion, the object or the robot arm should not be damaged. The interaction forces are important in such conditions. Whether the task succeeds or fails depends on how accurate the interaction forces are controlled. The interaction forces are changed depending on the motion of the robot arm. Therefore, to control interaction forces a force control algorithm must be developed. In this research a force control algorithm will first be developed for the quasi-static contact tasks, then it will be extended to the dynamic cases. The goal of this study is to compare force control strategies to achieve the desired interaction forces between the robot arm tip (end-effector) and the environment during contact tasks. Taguchi L9 method is used for comparison of selected force control algorithms which are modeled in SIMULINK MATLAB program.

Control Algorithms for Semi-Active Structural Systems: Do they Really Matter?

2008 ◽  
Vol 56 ◽  
pp. 182-187
Author(s):  
Antonio Occhiuzzi
Keyword(s):  
Control System ◽  
Control Systems ◽  
Active Control ◽  
Structural Control ◽  
Control Algorithm ◽  
Scientific Literature ◽  
Control Algorithms ◽  
Control Law ◽  
Structural Systems ◽  
Active Structural Control

Control algorithms for semi-active structural control system found in the scientific literature often rely on the choice of several parameters included in the control law. The present paper shows the preliminary conclusions of a study aiming to explain the weak dependency of the response reduction associated to semi-active control systems on the particular choice of the control algorithm adopted, provided that the relevant parameters of any control law be properly tuned.

Performance Comparison of Star Connected Cascaded STATCOM Using Different PWM Techniques

2017 ◽  
Vol 8 (3) ◽  
pp. 1303
Author(s):  
Ch. Lokeshwar Reddy ◽  
P. Satish Kumar ◽  
M. Sushama
Keyword(s):  
Reactive Power ◽  
Control Strategies ◽  
Performance Comparison ◽  
Control Algorithms ◽  
Performance Parameters ◽  
Space Vector ◽  
Third Harmonic ◽  
Voltage Balancing ◽  
Control Techniques

<p><span>Five control algorithms are presented in this paper for STATCOM that meets the requirement of load reactive power and correspondingly voltage balancing of isolated dc capacitors for H-bridges. The control techniques used for an inverter in this paper are Sinusoidal Phase Shifted Carrier (SPSC) PWM, Sinusoidal Phase Disposition (SPD) PWM Third Harmonic Injected Phase Shifted Carrier (THIPSC) PWM, Space Vector Phase Shifted Carrier (SVPSC) PWM, and Space Vector Phase Disposition (SVPD) PWM techniques.  The STATCOM performance for the different load changes is simulated in MATLAB environment. The performance parameters such as balancing the DC link voltage, THD for the STATCOM output currents, voltages, and reactive components supplied by the STATCOM to the load are compared for all the control strategies.</span></p>

Mixed Skyhook and Power-Driven-Damper: A New Low-Jerk Semi-Active Suspension Control Based on Power Flow Analysis

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Yilun Liu ◽  
Lei Zuo
Keyword(s):  
Active Control ◽  
Power Flow ◽  
Flow Analysis ◽  
Linear Quadratic Regulator ◽  
Control Algorithms ◽  
Linear Quadratic ◽  
Active Suspensions ◽  
Switching Law ◽  
Suspension Control ◽  
Optimal Linear

In practice, semi-active suspensions provide better tradeoffs between performances and costs than passive or active damping. Many different semi-active control algorithms have been developed, including skyhook (SH), acceleration-driven-damper (ADD), power-driven-damper (PDD), mixed SH and ADD (SH-ADD), and others. Among them, it has been shown that the SH-ADD is quasi-optimal in reducing the sprung mass vibration. In this paper, we analyze the abilities of vehicular suspension components, the shock absorber and the spring, from the perspective of energy transfer between the sprung mass and the unsprung mass, and propose a new sprung mass control algorithm named mixed SH and PDD (SH-PDD). The proposed algorithm defines a switching law that is capable of mixing SH and PDD, and simultaneously carries their advantages to achieve a better suspension performance. As a result, the proposed SH-PDD is effective in reducing the sprung mass vibration across the whole frequency spectrum, similar to SH-ADD and much better than SH, PDD, and ADD, while eliminating the control chattering and high-jerk behaviors as occurred in SH-ADD. The superior characteristics of the SH-PDD are verified in numerical analysis as well as experiments. In addition, the proposed switching law is extended to mix other semi-active control algorithms such as the mixed hard damping and soft damping, and the mixed SH and clipped-optimal linear quadratic regulator (LQR).

Comparison of Active Control Algorithms for Rotor Unbalance Compensation

2007 ◽  
Author(s):  
Kari Tammi ◽  
Antti Laiho
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Laboratory Scale ◽  
Experimental Comparison ◽  
Control Algorithms ◽  
Electromagnetic Actuator ◽  
Electrical Machine ◽  
Test Rig ◽  
Short Introduction ◽  
Scale Test

This paper shows a short introduction to three unbalance compensation algorithms and an experimental comparison of those algorithms. The algorithms have been tested experimentally on a laboratory-scale test rig equipped with an electromagnetic actuator. So called Convergent Control algorithm has been found the most suitable for the current purpose in terms of performance and simplicity. The algorithms are subjected further tests on rotor unbalance compensation in an electrical machine. This paper shows some initial considerations for those further tests.

Semi-Active Vibration Control Structure with MR-TLCD under Wind Load

2012 ◽  
Vol 446-449 ◽  
pp. 1713-1717
Author(s):  
Hong Xin Sun ◽  
Xiu Yong Wang
Keyword(s):  
Energy Dissipation ◽  
Control Algorithm ◽  
Passive Control ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Coupled System ◽  
Wind Load ◽  
Coupled Systems ◽  
Lagrange Equations ◽  
Load Response

The equation of motion for the coupled system of structure—MR-TLCD is formulated by Lagrange equations in this paper. Wind load response of a single-degree-of-freedom structure with MR-TLCD is obtained by time domain method. From the point of view energy dissipation force of MR-TLCD, the Simple Bi-State (SBS) control algorithm control algorithm is developed based on energy dissipation. By applying semi-active and passive control strategies, the controlled wind load response of the coupled system excited by wind load are numerically simulated. The peak value and root mean square value of the displacement and acceleration are obtained and the control effects of the system using the SBS algorithms. The results showed that the wind load responses of the coupled systems could be controlled effectively by applying the MR-TLCD.

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