In this study, the Field Programmable Gate Array (FPGA) technology is employed to integrate multi-loop controllers for motion systems. To provide precise positioning and trajectory tracking for multi-axis systems, the...
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In this study, the Field Programmable Gate Array (FPGA) technology is employed to integrate multi-loop controllers for motion systems. To provide precise positioning and trajectory tracking for multi-axis systems, the proportional-integral (PI) control is used in the speed control loop and adaptive PID control in the position control loop. The motion system under consideration comprises an X-Y table driven by permanent magnet synchronous motors (PMSMs), and controlled by two programmable servo systems, each designed to regulate a separate axis. Each axis of this system consists of a motion planning module, a speed PI controller in the inner loop, and an adaptive PID position controller in the outer loop. The adaptive PID controller is specifically designed using a multilayer perceptron (MLP) neural network and parameter tuning methods. The control objective is to enhance trajectory tracking accuracy, especially in the presence of dynamic variations and uncertain disturbances. The Very High-speed IC Hardware Description Language (VHDL) is utilized to implement the desirable features of the control system. The control development is based on an FPGA device using Altera's Quartus ii and Nios ii software environment. The VHDL designs are analyzed and synthesized within this software environment. Simulation results demonstrate that the on-chip control system can achieve accurate positioning and tracking performance for the X-Y table motion.
This paper addresses the trajectory tracking problem for a class of uncertain manipulator systems under the effect of external disturbances. The main challenges lie in the input constraints and the lack of measurement...
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This paper addresses the trajectory tracking problem for a class of uncertain manipulator systems under the effect of external disturbances. The main challenges lie in the input constraints and the lack of measurements of joint velocities. An extend-state-observer is utilized to estimate the velocity signals;then, a neural-network-based adaptive controller is proposed to solve the problem, where a term based on the nominal model is included to enhance the tracking ability, and the effect of uncertainties and disturbances are compensated by a neural-network term. Compared with the existing methods, the main distinctive features of the presented approach are: (i) The control law is guaranteed to be bounded by design, instead of directly bounded by a saturation function. (ii) The trade-off between the performance and robustness of the presented controller can be easily tuned by a parameter that depends on the size of model uncertainties and external disturbances. By virtue of the Lyapunov theorem, the convergence properties of the proposed controller are rigorously proved. The performance of the controller is validated via both simulations and experiments conducted on a two-degree-of-freedom robot manipulator. This paper addresses the trajectory tracking problem for a class of uncertain manipulator systems in the presence of external disturbances, input constraints, and the lack of measurement of joint velocities. The control law is guaranteed to be bounded by design, instead of using a saturation function. The performance of the controller is verified via the simulation and experiment of a Kinova manipulator. image
This article proposes an intent-based closedloop security control (ICSC) system for intelligent and effective security service management. Recent advancements in computer network technologies have led to the emergence...
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This article proposes an intent-based closedloop security control (ICSC) system for intelligent and effective security service management. Recent advancements in computer network technologies have led to the emergence of intent-based networking (IBN), significantly improving network security management. This article presents novel contributions to IBN, emphasizing intent fulfillment and intent assurance within network security. The proposed approach in this article utilizes a standardized framework called interface to network security functions (I2NSF) with standardized communication protocols and data models, allowing the deployment of security policies across multi-vendor environments. Furthermore, the existing security policy translator for an intent is extended to support dynamic translation, enabling the immediate integration of new security solutions into the network. An analytics component with machine learning is also introduced for continuous network monitoring, proactively identifying anomalies, and triggering automated threat mitigation. Additionally, the ICSC system's performance is assessed in various scenarios and configurations, providing a thorough understanding of its strengths and limitations. Thus, it is shown that the ICSC system can establish robust and adaptive network security management.
Synchronization is a typical dynamical behavior of interconnected systems that is being extensively studied in neural networks. However, most of the research considers real-valued neural networks, and fewer results ha...
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Synchronization is a typical dynamical behavior of interconnected systems that is being extensively studied in neural networks. However, most of the research considers real-valued neural networks, and fewer results have been obtained on their complex-valued counterparts. This article presents two sliding mode control strategies to achieve synchronization in a complex-valued neural network (CVNN). The former simplifies an already existing technique that splits the control into real and imaginary parts. The latter extends a fully complex-valued sliding approach for generic complex-valued dynamical systems to the multi-input-multi-output case, and shows its efficiency and higher performance in terms of finite reaching time in the synchronization of CVNNs. The approach is validated via numerical simulations.
This brief considers a trajectory tracking control issue of n-DOF mechatronic systems subject to uncertainties, mismatched disturbances, and input amplitude and rate saturations. In practical mechatronic systems, mism...
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This brief considers a trajectory tracking control issue of n-DOF mechatronic systems subject to uncertainties, mismatched disturbances, and input amplitude and rate saturations. In practical mechatronic systems, mismatched disturbances and input amplitude and rate saturations are common phenomenon affecting controlperformance, which require the development of an advanced and high-performancecontrol strategy. In this brief, a neural network observer (NNO)-based model-free prescribed-time saturated controller (NNO-MFPTSC) is designed which consists of ultra-local model-based adaptive RBF neural network observer, prescribed-time sub-controller, and auxiliary dynamic system. The proposed NNO-MFPTSC that overcomes mismatched disturbances achieves stabilization and convergence within predefined time and provides a torque with amplitude and rate saturations. After that, the stability and prescribed-time convergence are analyzed by using Lyapunov theorem. Finally, the co-simulation of 3-DOF PUMA 560 robotic manipulator based on SolidWorks and MATLAB is realized. The results compared to adaptive intelligent controller (AIC) are given to show the effectiveness and superiority of NNO-MFPTSC.
Ensuring stable frequency and voltage has recently become increasingly challenging for modern power systems. This is primarily due to the fluctuating and intermittent nature of renewable energy sources and the uncerta...
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This article extends the problem of safety of the intended functionality (SOTIF) to the platooning of connected autonomous vehicles (CAVs). In such multivehicle systems, SOTIF objectives are particularly challenging, ...
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This article extends the problem of safety of the intended functionality (SOTIF) to the platooning of connected autonomous vehicles (CAVs). In such multivehicle systems, SOTIF objectives are particularly challenging, since new issues arise due to the presence of interactions that propagate and intensify the effects and the risk connected to faults/failures/uncertainties, triggered by any platoon member and external conditions. To tackle and solve the SOTIF-oriented platoon control problem, we propose a robust and resilient decentralized control protocol, based on distributed observer which exploits the information shared via the Vehicle-to-Everything (V2X) communication network. The approach allows maintaining acceptable SOTIF performance in adversarial conditions, mitigating the effects of the unreasonable risks originated from sensors/actuators performance limitations/faults and disturbances. The uniformly ultimate bounded (UUB) stability and the input-to-state string stability (ISSS) of the platoon dynamics are analytically proved via the Lyapunov theory. Feasible linear matrix inequalities (LMIs) are obtained as stability conditions, whose solution allows adapting the distributed control/observer gains according to leader-tracking performance and robustness margins. A detailed analysis via the vehicular co-simulation platform mixed traffic simulator (MiTraS) corroborates the theoretical derivations and shows the achievement of the SOTIF platoon goals for a set of nontrivial and uncertain driving scenarios.
performance of controlsystems interacting over a shared communication network is tightly coupled with how the network provides services and distributes resources. Novel networking technology such as 5G is capable of ...
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performance of controlsystems interacting over a shared communication network is tightly coupled with how the network provides services and distributes resources. Novel networking technology such as 5G is capable of providing tailored services for a variety of network demands. Stringent control requirements and their critical performance specification call for online adaptable and control-aware network services. This perspective suggests a co-design of physical and network layers aiming to ensure that the necessary quality-of-service is provided to achieve the desired quality-of-control. An optimal co-design is in general challenging due to cross-layer couplings between the physical and network layers and their layer-specific functionalities. Furthermore, the complexity of the co-design depends on the level of actionable information the layers share with each other. In this Part I of a two-letter series, we present a general co-design of physical operations and service allocation aiming to minimize a social regret measure for networked controlsystems. We introduce an optimal networked co-design scenario using the regret index as the joint quality-of-control and quality-of-service (QoC-QoS) measure, and discuss the role of cross-layer awareness in the structure of optimization problems. We mainly focus on the finite-horizon case but we briefly present the infinite-horizon case as well. In Part ii, we discuss regret-optimal cross-layer policies for Gauss-Markov systems and derive the optimal solutions based on the general problems introduced in Part I.
This brief focuses on the motion control issue for uncertain robotic manipulators with unknown nonlinear dynamics and exogenous disturbances simultaneously via the output position measurement only. In detail, the exte...
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This brief focuses on the motion control issue for uncertain robotic manipulators with unknown nonlinear dynamics and exogenous disturbances simultaneously via the output position measurement only. In detail, the extended state observer is employed to obtain the estimations of immeasurable system state information and lumped disturbances simultaneously. Meanwhile, the multilayer neural network with good approximation performance is incorporated into the observer-controller scheme to identify the unknown nonlinear dynamics. As a result, both large nonlinear dynamics and strong lumped disturbances can be compensated feedforwardly. Significantly, prescribed tracking performance and asymmetric time-varying state constraints can be realized simultaneously.
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