scholarly journals Sensitivity-enhancing feedback control–based damage detection in delaminated smart composite plates

2019 ◽  
Vol 15 (7) ◽  
pp. 155014771986222
Author(s):  
Yan Guo ◽  
Yanan Jiang ◽  
Zhenghua Qian ◽  
Bin Huang

In this article, we present a sensitivity-enhancing feedback control–based damage detection method for piezoelectric actuator and sensor bonded composite laminates with delamination failures. The present method mainly consists of two parts: delamination modeling and feedback controller design. We first introduce the adopted improved layerwise theory–based mathematical model for delamination modeling with finite element implementation. The obtained second-order governing equations are transformed into the state space model for design of state feedback controller. Proper pole placement is required to enhance the sensitivity of frequency shifts to stiffness change caused by delamination. We investigated different delamination interfaces and longitudinal locations for studying the feasibility and efficiency of the present method. The present results clearly demonstrate that with the applied state feedback controller, the frequency shifts of the closed-loop system are significantly enhanced. The proposed sensitivity-enhancing feedback control can be used as an efficient tool for detecting delamination failures in smart composite structures.

2018 ◽  
Vol 120 (5) ◽  
pp. 2466-2483 ◽  
Author(s):  
Frederic Crevecoeur ◽  
Isaac Kurtzer

Successful performance in many everyday tasks requires compensating unexpected mechanical disturbance to our limbs and body. The long-latency reflex plays an important role in this process because it is the fastest response to integrate sensory information across several effectors, like when linking the elbow and shoulder or the arm and body. Despite the dozens of studies on inter-effector long-latency reflexes, there has not been a comprehensive treatment of how these reveal the basic control organization that sets constraints on any candidate model of neural feedback control such as optimal feedback control. We considered three contrasting ways that controllers can be organized: multiple independent controllers vs. a multiple-input multiple-output (MIMO) controller, a continuous feedback controller vs. an intermittent feedback controller, and a direct MIMO controller vs. a state feedback controller. Following a primer on control theory and review of the relevant evidence, we conclude that continuous state feedback control best describes the organization of inter-effector coordination by the long-latency reflex.


Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 359
Author(s):  
Nan Liu ◽  
Hui Pang ◽  
Rui Yao

In order to achieve better dynamics performances of a class of automobile active suspensions with the model uncertainties and input delays, this paper proposes a generalized robust linear H2/H∞ state feedback control approach. First, the mathematical model of a half-automobile active suspension is established. In this model, the H∞ norm of body acceleration is determined as the performance index of the designed controller, and the hard constraints of suspension dynamic deflection, tire dynamic load and actuator saturation are selected as the generalized H2 performance output index of the designed controller to satisfy the suspension safety requirements. Second, a generalized H2/H∞ guaranteed cost state-feedback controller is developed in terms of Lyapunov stability theory. In addition, the Cone Complementarity Linearization (CCL) algorithm is employed to convert the generalized H2/H∞ output-feedback control problem into a finite convex optimization problem (COP) in a linear matrix inequality framework. Finally, a numerical simulation case of this half-automobile active suspension is presented to illustrate the effectiveness of the proposed controller in frequency-domain and time-domain.


Author(s):  
George T. Flowers ◽  
Gyorgy Szasz ◽  
Victor S. Trent ◽  
Michael E. Greene

State feedback controller designs allow for pole-placement in an effective manner, but reduction of static offset is difficult. On the other hand, classical control methodology allows for the increase of system type and the elimination of static offset. An integrally augmented state feedback controller provides the benefits of standard feedback designs while allowing for the elimination of static offsets (through the increase of system type). Static offset is a particular problem with magnetic bearing supported rotor systems, in that gravitational effects, current biasing, and operational loading tend to exacerbate this problem. In order to assess the effectiveness of this technique, an integrally augmented state feedback controller is developed, implemented, and tested for a magnetic bearing supported rotor system. Results for several selected configurations are presented and compared. Some conclusions and recommendations concerning the effectiveness of integrally augmented state feedback controller designs are presented.


2012 ◽  
Vol 229-231 ◽  
pp. 2161-2165
Author(s):  
Ya Nan Yu ◽  
Xiu Yun Meng ◽  
Li Chao Ma

PD state-feedback controller has been adopted in many spacecraft for attitude tracking and presents good performance. For flexible spacecraft, the controller can be designed with a term which takes into account the flexible dynamics. However, duo to nonlinearity and coupling, how to determine state-feedback control parameters which ensure fast attitude tracking and significant vibration suppression must be considered. In this paper, the dynamics model of spacecraft with flexible appendages is derived with the hybrid coordinate method and the full state feedback controller originated from the PD control algorithm is designed. A method of estimating the flexible spacecraft's controller parameters based on the particle swarm optimization (PSO) algorithm is presented. Taking the PD controller parameters as optimized variables, optimal control state is defined as the linear weighted sum of response error of all state variables is smallest with the limited actuator output moment. Simulation results show that the optimized controller obtained by PSO algorithm makes attitude of spacecraft converge quickly and elastic vibration suppressed effectively.


Author(s):  
Andrea Wéber ◽  
Miklós Kuczmann

The paper presents a method for designing a state feedback controller of an active suspension system of a quarter car model. This is a survey based on a specific example. The designed controller of the active suspension system improves the driving control, safety and stability, because during the ride, the periodic swinging motion generated by the road irregularities on wheels can be decreased. This periodic motion damages the driving comfort, and may cause traffic accidents. The state feedback controller is designed to stand road induced displacements. Computer simulations of the designed controller have been performed in the frame of Scilab and XCos.


Author(s):  
Omar Waleed Abdulwahhab

This paper presents designing an adaptive state feedback controller (ASFC) for a magnetic levitation system (MLS), which is an unstable system and has high nonlinearity and represents a challenging control problem. First, a nonadaptive state feedback controller (SFC) is designed by linearization about a selected equilibrium point and designing a SFC by pole-placement method to achieve maximum overshoot of 1.5% and settling time of 1s (5% criterion). When the operating point changes, the designed controller can no longer achieve the design specifications, since it is designed based on a linearization about a different operating point. This gives rise to utilizing the adaptive control scheme to parameterize the state feedback controller in terms of the operating point. The results of the simulation show that the operating point has significant effect on the performance of nonadaptive SFC, and this performance may degrade as the operating point deviates from the equilibrium point, while the ASFC achieves the required design specification for any operating point and outperforms the state feedback controller from this point of view.


1997 ◽  
Vol 123 (2) ◽  
pp. 377-382 ◽  
Author(s):  
G. T. Flowers ◽  
G. Sza´sz ◽  
V. S. Trent ◽  
M. E. Greene

State feedback controller designs allow for pole placement in an effective manner, but reduction of static offset is difficult. On the other hand, classical control methodology allows for the increase of system type and the elimination of static offset. An integrally augmented state feedback controller provides the benefits of standard feedback designs while allowing for the elimination of static offsets (through the increase of system type). Static offset is a particular problem with magnetic bearing supported rotor systems, in that gravitational effects, current biasing, and operational loading tend to exacerbate this problem. In order to assess the effectiveness of this technique, an integrally augmented state feedback controller is developed, implemented, and tested for a magnetic bearing supported rotor system. Results for several selected configurations are presented and compared. Some conclusions and recommendations concerning the effectiveness of integrally augmented state feedback controller designs are presented.


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