A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is *** paper mainly focuses on two types of possibly fast timevarying but bound...
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A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is *** paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain ***,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the ***,the dynamical equation in the form of state space is established by designing the angular tracking ***,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of ***,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is *** feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental *** paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.
Effective fault diagnosis and fault-tolerant control method for aeronautics electromechanical actuator is concerned in this *** borrowing the advantages of model-driven and data-driven methods,a fault tolerant nonsing...
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Effective fault diagnosis and fault-tolerant control method for aeronautics electromechanical actuator is concerned in this *** borrowing the advantages of model-driven and data-driven methods,a fault tolerant nonsingular terminal sliding mode control method based on support vector machine(SVM)is proposed.A SVM is designed to estimate the fault by off-line learning from small sample data with solving convex quadratic programming method and is introduced into a high-gain observer,so as to improve the state estimation and fault detection accuracy when the fault *** state estimation value of the observer is used for state reconfiguration.A novel nonsingular terminal sliding mode surface is designed,and Lyapunov theorem is used to derive a parameter adaptation law and a control *** is guaranteed that the proposed controller can achieve asymptotical stability which is superior to many advanced fault-tolerant *** addition,the parameter estimation also can help to diagnose the system faults because the faults can be reflected by the parameters *** comparative simulation and experimental results illustrate the effectiveness and advancement of the proposed controller compared with several other main-stream controllers.
Soft electromechanical sensors have led to a new paradigm of electronic devices for novel motion-based wearable applications in our daily lives. However, the vast amount of random and unidentified signals generated by...
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Soft electromechanical sensors have led to a new paradigm of electronic devices for novel motion-based wearable applications in our daily lives. However, the vast amount of random and unidentified signals generated by complex body motions has hindered the precise recognition and practical application of this technology. Recent advancements in artificial-intelligence technology have enabled significant strides in extracting features from massive and intricate data sets, thereby presenting a breakthrough in utilizing wearable sensors for practical applications. Beyond traditional machine-learning techniques for classifying simple gestures, advanced machine-learning algorithms have been developed to handle more complex and nuanced motion-based tasks with restricted training data sets. Machine-learning techniques have improved the ability to perceive, and thus machine-learned wearable soft sensors have enabled accurate and rapid human-gesture recognition, providing real-time feedback to users. This forms a crucial component of future wearable electronics, contributing to a robust human–machine interface. In this review, we provide a comprehensive summary covering materials, structures and machine-learning algorithms for hand-gesture recognition and possible practical applications through machine-learned wearable electromechanical sensors.
Cable-driven robots are characterized by a large workspace, high speed, and load-to-weight ratio, providing a new technology approach for large-scale autonomous 3D construction of lunar surface shelters. A novel deplo...
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Since backlash nonlinearity is inevitably existing in actuators for bidirectional stabilization system of allelectric tank,it behaves more drastically in high maneuvering *** this work,the accurate tracking control fo...
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Since backlash nonlinearity is inevitably existing in actuators for bidirectional stabilization system of allelectric tank,it behaves more drastically in high maneuvering *** this work,the accurate tracking control for bidirectional stabilization system of moving all-electric tank with actuator backlash and unmodeled disturbance is *** utilizing the smooth adaptive backlash inverse model,a nonlinear robust adaptive feedback control scheme is *** unknown parameters and unmodelled disturbance are addressed separately through the derived parametric adaptive function and the continuous nonlinear robust *** the unknown backlash parameters are updated via adaptive function and the backlash effect can be suppressed successfully by inverse operation,which ensures the system ***,the system disturbance in the high maneuverable environment can be estimated with the constructed adaptive law online improving the engineering ***,Lyapunov-based analysis proves that the developed controller can ensure the tracking error asymptotically converges to zero even with unmodeled disturbance and unknown actuator *** co-simulations and experiments illustrate the advantages of the proposed approach.
Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(gly...
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Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous *** were carried out on an optical ball-on-disc tribometer under rolling/sliding *** film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body *** results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based *** studied liquids themselves are almost *** the addition of water,the signs of shear thinning behavior disappear even *** conditions for this type of lubricant can be predicted using the known Hamrock–Dowson *** anomaly in the thickness of the lubricants was observed as an abrupt change at certain *** more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.
Considering the dynamic variation of roll gap and the transverse distribution of dynamic rolling force along the work roll width direction, the movement and deformation of rolls system, influenced by the coupling of v...
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Considering the dynamic variation of roll gap and the transverse distribution of dynamic rolling force along the work roll width direction, the movement and deformation of rolls system, influenced by the coupling of vertical chatter and transverse bending vibration, may cause instability and also bring product defect of thickness difference. Therefore, a rigid-flexible coupling vibration model of the rolls system was presented. The influence of dynamic characteristics on the rolling process stability and strip thickness distribution was investigated. Firstly, assuming the symmetry of upper and lower structures of six-high rolling mill, a transverse bending vibration model of three-beam system under simply supported boundary conditions was established, and a semi-analytical solution method was proposed to deal with this model. Then, considering both variation and change rate of the roll gap, a roll vertical chatter model with structure and process coupled was constructed, and the critical rolling speed for self-excited instability was determined by Routh stability criterion. Furthermore, a rigid-flexible coupling vibration model of the rolls system was built by connecting the vertical chatter model and transverse bending vibration model through the distribution of dynamic rolling force, and the dynamic characteristics of rolls system were analyzed. Finally, the strip exit thickness distributions under the stable and unstable rolling process were compared, and the product shape and thickness distribution characteristics were quantitatively evaluated by the crown and maximum longitudinal thickness difference.
The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through *...
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The primary goal of this study is to develop cost-effective shield materials that offer effective protection against high-velocity ballistic impact and electromagnetic interference(EMI)shielding capabilities through *** fiber-reinforced epoxy composite panels,each with a different fabric material and stacking sequence,have been fabricated using a hand-layup vacuum bagging *** panels made of Kevlar and glass fibers,referred to as(K-NIJ)and(G-NIJ),have been tested according to the National Institute of Justice ballistic resistance protective materials test NIJ 0108.01 Standard-Level IIIA(9 mm×19 mm FMJ 124 g)*** panels,namely,a hybrid of Kevlar and glass(H-S),glass with ceramic particles(C-S),and glass with recycled rubber(R-S)have been impacted by the bullet at the center,while the fourth panel made of glass fiber(G-S)has been impacted at the *** shielding properties have been measured in the X-band frequency range via the reflection-transmission *** indicate that four panels(K-NIJ,G-NIJ,H-S,and G-S)are capable of withstanding high-velocity impact by stopping the bullet from penetrating through the panels while maintaining their structural ***,under such conditions,these panels may experience localized delamination with variable *** EMI measurements reveal that the highest absorptivity observed is 88% for the KNIJ panel at 10.8 GHz,while all panels maintain an average absorptivity above 65%.All panels act as a lossy medium with a peak absorptivity at different frequencies,with K-NIJ and H-S panels demonstrating the highest *** summary,the study results in the development of a novel,costeffective,multifunctional glass fiber epoxy composite that combines ballistic and electromagnetic interference shielding *** material has been developed using a simple manufacturing method and exhibits remarkable ballistic protection that outperforms Kevlar in terms of shielding efficiency;no bullet
This article focuses on asymptotic precision motion control for electro-hydraulic axis systems under unknown time-variant parameters,mismatched and matched *** from the traditional adaptive results that are applied to...
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This article focuses on asymptotic precision motion control for electro-hydraulic axis systems under unknown time-variant parameters,mismatched and matched *** from the traditional adaptive results that are applied to dispose of unknown constant parameters only,the unique feature is that an adaptive-gain nonlinear term is introduced into the control design to handle unknown time-variant *** both mismatched and matched disturbances existing in electro-hydraulic axis systems can also be addressed in this *** skillful integration of the backstepping technique and the adaptive control,a synthesized controller framework is successfully developed for electro-hydraulic axis systems,in which the coupled interaction between parameter estimation and disturbance estimation is ***,this designed controller has the capacity of low-computation costs and simpler parameter tuning when compared to the other ones that integrate the adaptive control and observer/estimator-based technique to dividually handle parameter uncertainties and ***,a nonlinear filter is designed to eliminate the“explosion of complexity”issue existing in the classical back-stepping *** stability analysis uncovers that all the closed-loop signals are bounded and the asymptotic tracking performance is also ***,contrastive experiment results validate the superiority of the developed method as well.
Augmenting the productivity of fresh water with minimum environmental impact is a challenging task for researchers across the globe. Solar desalination is an environment-friendly approach with minimum CO2 emissions. R...
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