scholarly journals A Hybrid Nonlinear Active Control Strategy Combining Dry Friction Control and Nonlinear Velocity Compensation Control

2021 ◽  
Vol 11 (24) ◽  
pp. 11670
Author(s):  
Donglai Yang ◽  
Xingrong Huang ◽  
Xiaodong Yang
Keyword(s):  
Active Control ◽  
Friction Force ◽  
Control Strategy ◽  
Dry Friction ◽  
Vibration Suppression ◽  
Hybrid Control ◽  
Control Law ◽  
Control Force ◽  
Friction Dampers ◽  
Nonlinear Velocity

Friction dampers are widely used in structural vibration suppression in various fields, such as aeronautics, astronautics, robotics, precision manufacturing, etc. Traditional friction dampers are mainly used in a passive way to optimize vibration suppression with an immutable pressure around certain excitation. In this manuscript, a hybrid control strategy by considering both the friction force in the active control law and a nonlinear velocity compensation force is put forward: First, the normal force applied on the friction damper was adjusted to ensure its vibration reduction effect under different excitation for a first passive control; second, the active control law was established by combining the dry friction force and the velocity control force in the state space; lastly, the stability of the nonlinear control law was determined by Lyapunov criterion. Numerical simulations were conducted on a three degree-of-freedom system (3-DOF) based on the proposed hybrid control strategy, to show the control efficiency in vibration suppression and economic efficiency in energy input into the system. Simulation results showed that the proposed control law could reduce the amplitude of the active control force by about 5% without degrading the control efficiency.

Stochastic optimal semi-active control of stay cables by using magneto-rheological damper

2010 ◽  
Vol 17 (13) ◽  
pp. 1921-1929 ◽  
Author(s):  
M Zhao ◽  
WQ Zhu
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
Mr Damper ◽  
Stochastic Averaging ◽  
Control Law ◽  
Control Force ◽  
Stay Cable ◽  
Dynamical Programming ◽  
Magneto Rheological ◽  
Bang Bang Control

Stochastic optimal semi-active control for stay cable multi-mode vibration attenuation by using magneto-rheological (MR) damper is developed. The Bingham model for an MR damper is used. The force produced by an MR damper is split into passive and active parts. The passive part is combined with structural damping forces into effective damping forces. The partially averaged Itô stochastic differential equations for controlled modal energies are derived by applying the stochastic averaging method for quasi-integrable Hamiltonian systems. Then the dynamical programming equation for controlled modal energies with an index involving control force is established by applying the stochastic dynamical programming principle, and a stochastic optimal semi-active control law is obtained by solving the dynamical programming equation. For controlled modal energies with an index not involving control force, bang-bang control law is obtained without solving a dynamical programming equation. A comparison between the two control laws shows that the stochastic optimal semi-active control strategy is superior to the bang-bang control strategy in the sense of higher control effectiveness and efficiency and less chattering.

Semi-Active Control of Structural Systems Aiming to Approximate the Performance of the Targeted Active Control Law: Output Emulation Approach

2013 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda
Keyword(s):  
Control System ◽  
Active Control ◽  
Variable Parameter ◽  
Control Law ◽  
Structural Systems ◽  
Control Force ◽  
Control Performance ◽  
Control Devices ◽  
Active Control System ◽  
Control Output

As a method for semi-active control of structural systems, the active-control-based method that emulates the control force of a targeted active control law by semi-active control devices has been studied. In the active-control-based method, the semi-active control devices are not necessarily able to generate the targeted active control force because of the dissipative nature of those devices. In such a situation, the meaning of the targeted active control law becomes unclear in the sense of the control performance achieved by the resulting semi-active control system. In this study, a new semi-active control strategy that approximates the control output (not the control force) of the targeted active control is proposed. The variable parameter of the semi-active control device is selected at every time instant so that the predicted control output of the semi-active control system becomes close to the corresponding predicted control output of the targeted active control as much as possible. Parameters of the targeted active control law are optimized in the premise of the above “output emulation” strategy so that the control performance of the semi-active control becomes good and the “error” of the achieved control performance between the targeted active control and the semi-active control becomes small.

Seismic Protection of Structures Using Tuned Mass Dampers with Resettable Variable Stiffness

2012 ◽  
Vol 83 ◽  
pp. 75-84
Author(s):  
Chi Chang Lin ◽  
Tsu Teh Soong
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
Good Control ◽  
Variable Stiffness ◽  
Seismic Protection ◽  
Control Law ◽  
Control Performance ◽  
Deformation Diagram ◽  
Tuned Mass Dampers ◽  
Engineering Structures

Vibration control of civil engineering structures using tuned mass dampers (TMD) is a widely accepted control strategy after numerous analytical and experimental verifications. Although the design and application of traditional linear TMD systems are well developed, nonlinear TMD systems that may lead to better control performance are still in the developmental stage. There are two main problems associated with TMD systems, i.e. (1) detuning effect and (2) excessive stroke of TMD. In order to improve the performance of TMD systems, a novel semi-active TMD named resettable variable stiffness TMD (RVS-TMD) is proposed in this study. The RVS-TMD consists of a TMD and a resettable variable stiffness device (RVSD). The RVSD is composed of a resettable element and a controllable stiffness element. By varying the stiffness element of the RVSD, the force produced by the RVSD can be controlled smoothly through a semi-active control law. By resetting the resettable element, the hysteresis loop of the RVSD can cover all four quadrants in the force-deformation diagram and thus results in more energy dissipation. The harmonic and seismic responses of a building equipped with the RVS-TMD are investigated numerically and compared with those by its active control counterpart and an optimal passive TMD system. The results show that the proposed RVS-TMD system has good control performances as its active control counterpart and is able to alleviate detuning effect and reduce TMD’s stroke.

scholarly journals Hybrid Electromagnetic Shunt Damper for Vibration Control

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Ahmad Paknejad ◽  
Guoying Zhao ◽  
Simon Chesné ◽  
Arnaud Deraemaeker ◽  
Christophe Collette
Keyword(s):  
Control System ◽  
Power Consumption ◽  
Control Systems ◽  
Active Control ◽  
Hybrid Control ◽  
Current Source ◽  
Voltage Source ◽  
Control Law ◽  
Electromagnetic Devices ◽  
Hybrid Control System

Abstract It has been shown that shunting electromagnetic devices with electrical networks can be used to damp vibrations. These absorbers have however limitations that restrict the control performance, i.e., the total damping of the system and robustness versus parameter variations. On the other hand, the electromagnetic devices are widely used in active control techniques as an actuator. The major difficulty that arises in practical implementation of these techniques is the power consumption required for conditioners and control units. In this study, robust hybrid control system is designed to combine the passive electromagnetic shunt damper with an active control in order to improve the performance with low power consumption. Two different active control laws, based on an active voltage source and an active current source, are proposed and compared. The control law of the active voltage source is the direct velocity feedback. However, the control law of the active current source is a revisited direct velocity feedback. The method of maximum damping, i.e., maximizing the exponential time-decay rate of the response subjected to the external impulse forcing function, is employed to optimize the parameters of the passive and the hybrid control systems. The advantage of using the hybrid control configuration in comparison with purely active control system is also investigated in terms of the power consumption. Besides these assets, it is demonstrated that the hybrid control system can tolerate a much higher level of uncertainty than the purely passive control systems.

Application of Semi-Active Inerter in Semi-Active Suspensions Via Force Tracking

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Michael Z. Q. Chen ◽  
Yinlong Hu ◽  
Chanying Li ◽  
Guanrong Chen
Keyword(s):  
Active Control ◽  
Ride Comfort ◽  
Controller Design ◽  
Active Suspension ◽  
Damping Coefficient ◽  
Control Law ◽  
Control Force ◽  
Car Model ◽  
Force Tracking ◽  
Active Damper

This paper investigates the application of semi-active inerter in semi-active suspension. A semi-active inerter is defined as an inerter whose inertance can be adjusted within a finite bandwidth by online control actions. A force-tracking approach to designing semi-active suspension with a semi-active inerter and a semi-active damper is proposed in this paper. Two parts are required in the force-tracking strategy: a target active control law and a proper algorithm to adjust the inertance and the damping coefficient online to track the target active control law. The target active control law is derived based on the state-derivative feedback control methodology in the “reciprocal state-space” (RSS) framework, which has the advantage that it is straightforward to use the acceleration information in the controller design. The algorithm to adjust the inertance and the damping coefficient is to saturate the active control force between the maximal and the minimal achievable suspension forces of the semi-active suspension. Both a quarter-car model and a full-car model are considered in this paper. Simulation results demonstrate that the semi-active suspension with a semi-active inerter and a semi-active damper can track the target active control force much better than the conventional semi-active suspension (which only contains a semi-active damper) does. As a consequence, the overall performance in ride comfort, suspension deflection, and road holding is improved, which effectively demonstrates the necessity and the benefit of introducing semi-active inerter in vehicle suspension.

scholarly journals Dynamic Characteristics of a Segmented Supercritical Driveline with Flexible Couplings and Dry Friction Dampers

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 281
Author(s):  
Zhonghe Huang ◽  
Jianping Tan ◽  
Chuliang Liu ◽  
Xiong Lu
Keyword(s):  
Dry Friction ◽  
Vibration Suppression ◽  
Parameter Analysis ◽  
Friction Damper ◽  
Dynamic Effects ◽  
Angular Misalignment ◽  
Friction Dampers ◽  
Response Characteristics ◽  
Flexible Diaphragm ◽  
Simulation And Experiment

Helicopter tail rotors adopt a segmented driveline connected by flexible couplings, and dry friction dampers to suppress resonance. Modeling for this system can provide a basic foundation for parameter analysis. In this work, the lateral-torsional vibration equation of the shaft with continuous internal damping is established. The static and dynamic effects caused by flexible diaphragm couplings subject to parallel and angular misalignment is derived. A novel dual rub-impact model between the shaft and dry friction damper with multiple stages is proposed. Finally, a model of a helicopter tail rotor driveline incorporating all the above elements is formulated. Numerical simulations are carried out by an improved Adams–Bashforth method following the design flowchart. The dynamics of multiple vibration suppression, and the static and dynamic misalignment are analyzed to illustrate the accuracy and characteristics of the model. The coeffect of the rub impact and the misalignment on shafts and dampers are presented through the results of simulation and experiment. It provides an accurate and comprehensive mathematical model for the helicopter driveline. Response characteristics of multiple damping stages, static and dynamic misalignment, and their interaction are revealed.

Hybrid Active and Semi-Active Control for Vibration Suppression in Flexible Structures

2016 ◽  
Author(s):  
Irfan Ullah Khan ◽  
David Wagg ◽  
Neil D. Sims
Keyword(s):  
Active Control ◽  
Vibration Suppression ◽  
Hybrid Control ◽  
Sliding Mode ◽  
Flexible Structures ◽  
Active System ◽  
Active Device ◽  
Hybrid Controller ◽  
System A ◽  
Simulation And Experiment

A new hybrid control methodology is presented for vibration suppression in flexible structures, where an active actuator is used to assist a nearby semi-active device to achieve a control performance close to that of a fully active system. The clipping phenomenon, typical of semi-active control, is reduced to a large extent by the proposed hybrid controller. The immersion and invariance methodology along with sliding mode control is used to create the hybrid controller. The result is that as the semi-active controller switches off in the hybrid controller, the active actuator injects the required energy into the system. A two degree of freedom system with cubic stiffness is used as an example system. Both simulation and experiment data are presented to demonstrate the usefulness of the proposed idea. The proposed hybrid controller shows robust results as compared to just using a semi-active controller.

Effect of Response Related Weighting Matrices on Performance of Active Control Systems for Nonlinear Frames

2017 ◽  
Vol 17 (03) ◽  
pp. 1750030
Author(s):  
Mohtasham Mohebbi ◽  
Abdolreza Joghataie ◽  
Hamed Rasouli Dabbagh
Keyword(s):  
Control System ◽  
Control Systems ◽  
Active Control ◽  
Structural Response ◽  
Control Law ◽  
Control Force ◽  
Online Measurements ◽  
Active Control System ◽  
Distributed Genetic Algorithm ◽  
Response Feedback

In this paper, the effect of various arrangements of displacement, velocity and acceleration related weighting matrices on the performance of active control systems on nonlinear frames has been studied. Different arrangements of weighting matrices and feedback combinations of the response have been considered to design the active controllers using a single actuator for reducing the response of an eight-storey bilinear hysteretic frame under white noise excitations. The nonlinear Newmark-based instantaneous optimal control algorithm has been used, where the distributed genetic algorithm (DGA) is employed to determine the proper set of weighting matrices. For each set of feedback and weighting matrices, the active control system has been designed with the optimal weights determined. Here, the objective is to minimize the maximum control force required to reduce the maximum structural drift to a value below the desired level. The numerical results of simulation show that, for the cases studied, the use of different arrangements of weighting matrices in the proposed method for the performance index of the active control law has no significant impact on the performance of the active control system. However, the type of response feedback combination included in the control law considerably affects the performance, and the controllers designed based on velocity feedback have been found to be more effective. It was also shown that for all the weight-cases, using the full feedback of response can lead to design controllers that require minimum control force to reduce the structural response with more online measurements. The robustness of the designed controllers for different weighting matrices arrangements and feedback combinations has also been tested under a number of real earthquake excitations with the results discussed.

Hybrid Control Scheme of Coordinated Motion and Active Vibration Suppression for Free-Floating Space Flexible Manipulator With Parameter Uncertainty

2009 ◽  
Author(s):  
Zhaobin Hong ◽  
Chen Li
Keyword(s):  
Parameter Uncertainty ◽  
Vibration Suppression ◽  
Controller Design ◽  
Hybrid Control ◽  
Flexible Manipulator ◽  
Control Force ◽  
Coordinated Motion ◽  
Flexible Mode ◽  
Control Scheme ◽  
Hybrid Control Scheme

The dynamic control and vibration suppression problems of free-floating space flexible manipulator are studied. The Variable Structure Control (VSC) law alone, which is designed to track the desired trajectories of base’s attitude and joint angles, does not guarantee the stability of the flexible mode dynamics of the flexible link. In order to actively suppress the flexible vibration, a hybrid trajectory for the VSC is generated using the virtual control force concept. Based on the hybrid trajectory, the hybrid control scheme is proposed to eliminate the flexible vibration while the robustness of VSC developed for coordinated motion is maintained. In particular, it doesn’t require measuring the position, velocity nor acceleration of the base in the controller design. Simulation result confirms that the proposed hybrid control scheme can dominates the trajectory tracking of coordinated motion and actively suppress the vibration in the presence of parameter uncertainty.

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