In the current practical science, the accuracy in the formability of metal alloys being the goal when using electromagnetic forming (EMF) technology, which is a high-speed processing technology that uses Lorentz force...
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In the current practical science, the accuracy in the formability of metal alloys being the goal when using electromagnetic forming (EMF) technology, which is a high-speed processing technology that uses Lorentz forces to achieve plastic deformation of sheet metal;according to the previous analysis, the results have shown that in most cases, the Lorentz force acting on the workpiece (metal) is not uniform, there are uneven axial deformations of the metal plates which prevent the rapid advancement of today’s technology. In this article, we presented some advanced analyzes which will lead us to improve the technical solution for the problems of non-uniform axial deformations of the metals in the traditional tube electromagnetic forming technology (EMF). A field shaper is used as a practical forming tool to influence the magnetic field and magnetic pressure distribution, thereby improving the forming ability and result during the electromagnetic forming (EMF) process and we see that induced eddy current control is realized by changing the structural parameters of the magnetic field shaper;which improves the strength and controllability of the magnetic force that acts on the workpiece;thereby a greater radial magnetic pressure can be achieved with field shaper than the case without it;the field shaper regulates the electromagnetic force, the distribution of the magnetic pressure decreases, and the uniform force area of the tube increases which effectively enhances the uniform range of the pipe electromagnetic bulging and the electromagnetic induction coupling between the coil and the metallic workpiece is generally required to produce the Lorentz forces. Using COMSOL Multiphysics® simulation software helped us to accurately represent the real world, simulating multiple physical effects that happened in this model during the process.
Leader-following formation analysis problem for a second-order nonlinear multi-agent system(MAS) with input saturation is investigated in this paper. And the impulsive formation control algorithm is introduced in the ...
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Leader-following formation analysis problem for a second-order nonlinear multi-agent system(MAS) with input saturation is investigated in this paper. And the impulsive formation control algorithm is introduced in the designed protocol which only works at the impulse times. Owing to the real-world limited communication channels, input saturation is considered in the impulsive controller. Furthermore, based on Lyapunov stability theories, Kronecker properties, eigenvalue and so on, some sufficient conditions that guarantee the leader-following consensus of MAS are obtained. Lastly, several simulations are worked out to verify the correctness and effectiveness of the theoretical results.
With the development of Industry 4.0, mobile agents are deployed to coordinate with multi-loop controlsystems to perform manufacturing tasks, leading to heterogeneous Internet of Things (IoT). Due to shadow fading in...
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In this article, an adaptive event-triggered asymp¬totically fault-tolerant control (FTC) issue for nonlinear systems with actuator faults is investigated. An extended neural networks (NNs) technique is introduce...
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ISBN:
(数字)9798350363173
ISBN:
(纸本)9798350363180
In this article, an adaptive event-triggered asymp¬totically fault-tolerant control (FTC) issue for nonlinear systems with actuator faults is investigated. An extended neural networks (NNs) technique is introduced to estimate unknown functions of the system under consideration. Compared with traditional NNs that ignore approximation errors, the proposed extended NNs further processes approximation errors, reducing the conservatism of the proposed algorithm. Then, within the framework of backstepping method, a new adaptive control strategy is developed by combining event-triggered mechanism (ETM) and bound estimation (BE) approach, which ensures the asymptotic convergence of system states while also reducing the transmission of unnecessary information, thus improving the utilization of communication resources. At the same time, the designed controller eliminates the adverse effects of actuator failures and system nonlinear terms. Finally, a simulation example of a single-link robot system is provided to demonstrate that the developed control strategy can ensure that all signals are bounded and system states are asymptotically convergent.
The event-triggered line of sight(LOS) formation cooperative guidance under actuator fault is addressed in this ***,a composite variable including LOS angle rate and local LOS angle formation error is ***,a state upda...
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ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
The event-triggered line of sight(LOS) formation cooperative guidance under actuator fault is addressed in this ***,a composite variable including LOS angle rate and local LOS angle formation error is ***,a state update mechanism is designed to achieve global stability in the error of the multiple aircraft *** with sliding mode variable structure theory and adaptive control theory,a distributed event-triggered fault-tolerant cooperative guidance law and a corresponding design algorithm are *** addition,the convergence of the closed-loop LOS angle formation and LOS angle rate error is proved based on the Lyapunov stability *** stability conclusion also provides a proof to exclude the Zeno ***,a simulation validates the proposed event-triggered fault-tolerant cooperative guidance law.
The electrification of offshore oil and gas platforms (OOGPs), using offshore wind turbines, is now a reality, aimed at minimizing carbon emissions. In this scenario, the utilization of battery energy storage systems ...
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ISBN:
(数字)9798350368154
ISBN:
(纸本)9798350368161
The electrification of offshore oil and gas platforms (OOGPs), using offshore wind turbines, is now a reality, aimed at minimizing carbon emissions. In this scenario, the utilization of battery energy storage systems (BESS) improves both efficiency and power quality. As this integration comes with a high CAPEX, industries demand exploring BESS for multiple ancillary services on OOGPs. Thus, this paper proposes an alternative approach to energizing a power transformer (PT) using the BESS power conversion system (PCS) on the platform, aiming to minimize inrush currents. This avoids the necessity for additional bulky devices, converters, or dc voltage sources specifically designated for this purpose. The strategy consists of manipulating residual core flux using BESS PCS followed by a controlled switching, which reduces inrush currents during PT energization. The results show effective reduction of the inrush current from 2.31 pu to 0.16 pu for the presented case study.
This paper investigates distributed time-varying optimization-based formation tracking problems for discrete-time heterogeneous multi-agent systems with unknown disturbances. Firstly, an optimization-based formation t...
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ISBN:
(数字)9798350354409
ISBN:
(纸本)9798350354416
This paper investigates distributed time-varying optimization-based formation tracking problems for discrete-time heterogeneous multi-agent systems with unknown disturbances. Firstly, an optimization-based formation tracking problem with privacy preservation is established, which formulates the relation between the formation tracking and the distributed optimization on the formation reference. Then, a distributed formation tracking controller composing of differential privacy mechanism and stochastic subgradient method is designed. Furthermore, the privacy, stability and optimality are proved by utilizing the discrete-time Lyapunov method. Finally, numerical simulations demonstrate the effectiveness of the proposed method.
In this paper, we investigate the problem of reference tracking for a class of linear systems subject to actuator saturation and propose a performance-based model recovery anti-windup strategy. We adopt the classic mo...
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ISBN:
(数字)9798350382655
ISBN:
(纸本)9798350382662
In this paper, we investigate the problem of reference tracking for a class of linear systems subject to actuator saturation and propose a performance-based model recovery anti-windup strategy. We adopt the classic model recovery anti-windup framework and regard the states or one of the outputs of the anti-windup compensator as the tracking error, by which the difference between the unconstrained system and the saturated system is quantified. Then, instead of employing the commonly used
$\mathcal{L}_{2}$
gain, we present the prescribed performance functions (PPFs) to characterize the real-time tracking error such that the system performance can be captured more specifically. In particular, to avoid singular issues arising from the occurrence of saturation, we modify the existing PPFs with an auxiliary system when saturation occurs. Based on these modified performance functions, we follow a modified prescribed performance control approach and design the remaining output of the anti-windup compensator. Such a design procedure is constructive, making it more promising for extension to nonlinear systems. Theoretical results establish the boundedness of all signals in the closed-loop system. Simulation results verify the effectiveness of our design strategy.
Online learning of deep neural networks suffers from challenges such as hysteretic non-incremental updating, increasing memory usage, past retrospective retraining, and catastrophic forgetting. To alleviate these draw...
This article proposes a distributed consensus-based formation tracking and dynamic obstacle avoidance method for fixed wing unmanned aerial vehicles(UAVs).The tracking target moves along a pre-set geometric path,while...
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ISBN:
(数字)9789887581581
ISBN:
(纸本)9798350366907
This article proposes a distributed consensus-based formation tracking and dynamic obstacle avoidance method for fixed wing unmanned aerial vehicles(UAVs).The tracking target moves along a pre-set geometric path,while other UAVs automatically track the target to form various distributed formation shapes and always perform dynamic collision *** fixed wing UAVs in this article form a distributed formation based on information exchange between neighbors,and further the formation process is improved by incorporating position allocation into the formation ***,the fixed wing UAV is modeled and ***,a basic formation control protocol is designed based on consensus strategy,and a tracking target feedback is added on ***,an anti-collision controller and a variable formation position allocation strategy are designed to avoid the ***,the effectiveness of the presented method is verified through numerical simulations.
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