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This paper investigates the semi-global practical stabilization for second-order nonlinear systems subject to unknown control coefficients and completely unknown nonlinear function. In order to achieve the control objective, a state feedback controller is firstly constructed to ensure that systems under consideration satisfy uniform Lyapunov property. Then, based on output feedback domination method,...
In this paper, we study the state estimation problem for a general class of nonlinear systems subject to both non-Gaussian noise and exogenous disturbance. The exogenous disturbance under consideration can be treated as the output of a linear exogenous system. For this problem, direct application of the traditional particle filter (PF) may require an excessive number of particles and hence lead to...
The flight of unmanned aerial vehicle (UAV) is vulnerable to various disturbances and faults. In this paper, the small damage of the wing of an unmanned aerial vehicle is taken into consideration. The UAV control framework consists of force loop and torque loop, where the nonlinear disturbance observer (NDO) based dynamic inverse (DI) control and the extended state observer (ESO) based dynamic inverse...
In order to test the renewable energy grid-connect converters, a grid simulator is in need which is able to simulate grid transition such as voltage sags, unbalanced voltages, flicker and low-order harmonics. The main concern of this paper is on the harmonics generation. A compound control strategy is proposed on the basis of three-phase inverter to generate precise controllable required voltage harmonics...
This paper investigates the problem of attitude stabilization control for rigid spacecraft subject to actuator output deviation disturbance and external disturbances without angular velocity measurement. Firstly, an angular velocity observer is designed which ensures asymptotic convergence of angular velocity estimation error. Furthermore, taking actuator output deviation disturbance into consideration,...
We propose a novel system considering layered Pulse Amplitude Modulation with Discrete Hartley Transform (PAM-DHT), in order to improve Effective Data Transmission Efficiency (EDTE) by modulating both odd and even subcarriers. This system is suitable for the optical communication employing Intensity Modulation with Direct Detection (IM/DD). At the transmitter side of this system, signals are divided...
The paper studies this global output regulation of a class of two order Port-Controlled Hamiltonian Systems with mismatched disturbance by a composite control method. By combining the damping injection, the finite time disturbance observer (FTDO) and the coordinate transformation techniques together, the composite controller is developed. The novel idea is to design a coordinate transformation to...
In this study, a decentralized PID controller is proposed to solve the tracking problem for a class of multi-agents systems, where each agent is described by a second order nonlinear uncertain dynamical system, which only has access to its own tracking error information and does not need to communicate with others. We will show that a 3-dimensional manifold can be constructed based on the information...
A novel control scheme is presented in this work to address the attitude stabilization problem in the presence of actuator saturation, misalignment and lack of inertia information. Taking a hyperbolic tangent function in its formulation, the control signal explicitly obeys a known maximum-torque constraint. Considering the possible actuator misalignment, a dynamic attitude gain is introduced to accommodate...
An observer-based fault-tolerant control scheme is developed for the attitude stabilization control of the rigid spacecraft in the presence of constants and time-varying actuator faults as well as external disturbances. The proposed iterative learning observer employs a learning mechanism to estimate the fault torque values combined with external disturbances, furthermore, the sign function and the...
A fixed-time controller is introduced to achieve the relative motion tracking of leader-follower spacecraft within the allotted time. Unlike the existing finite time control scheme, of which settling time can't be determined in advance, a novel fixed-time sliding mode control scheme in conjunction with a time-varying sliding mode surface is proposed. This method can preset desired fixed-values for...
The generalization ability of learning algorithms is the focus of machine learning research, where the empirical risk minimization (ERM) plays an important role when the population distribution of observations is unknown. Most of the previous results are mainly based on computational learning theory, which is interested in how many samples are needed to make sure the estimated expected risk satisfies...
The converged Fiber-Wireless (FiWi) access network that can provide service to users with a high capacity, flexibility and reliability has become a promising “last mile” solution for the Fifth Generation (5G). Network virtualization is capable of shielding the heterogeneous features of physical networks and facing the emergence of Over the top (OTT) content, which is consistent with the vision of...
Compressive sensing (CS) technique is usually used to reconstruct the original signal (full-sampled signal) from using under-sampled signal. Based on the CS theory, the original signal can be reconstructed by using fewer signal samples which is obtained from a random measurement matrix. In this work, a CS algorithm using approximated total variant transform is used to reconstruct clear images in radar-based...
A wideband circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) is presented. The DRA is excited in its fundamental HEM11δ mode. A U-shaped slot and a fork-like feed line are used to obtain circularly polarized fields. For demonstration, a prototype operating at 2.4-GHz WLAN band was studied. The reflection coefficient, axial ratio (AR), radiation patterns, antenna gain, and radiation...
In this paper, we concentrate on the problem of attitude tracking control with guaranteed transient performance for a rigid spacecraft subject to unknown inertia properties and exogenous disturbances. A promising solution to the problem under consideration is presented. Specifically, certain performance functions specified a priori by the designer are first introduced to impose desired transient and...
This paper presents a novel approach for designing a composite controller that finite time simultaneously stabilizes two single input nonlinear Port-Controlled Hamiltonian (PCH) systems under disturbances. Firstly, using a single output feedback, two PCH systems are combined to generate an augmented PCH system based on the Hamiltonian structure properties. Then, a finite time disturbance observer...
In recent years, the system parameter identification attracts attention of scholars and engineers, as the system control precision can be improved with it. In this paper, we take advantage of Hopfield neural network to identify the system parameters. Firstly, a kind of self balancing vehicle dynamic model is proposed. Secondly, the subsystem of the self balancing vehicle is analyzed in the form of...
This paper addresses the observer-based composite control problem for a class of delta-domain LQ games with disturbances in both finite- and infinite-time horizon. In the presence of the disturbances, the Nash Equilibrium (NE) is revisited, and the scalar ε is proposed to describe the deviation of NE in such noise environment. A composite control strategy integrating the observer-based control and...
A kind of unicycle robot was designed. The mechanical structure can be divided into pitching subsystem and yaw subsystem. A kind of dynamic model was proposed based on Appell Equations. And the linear dynamic model of the unicycle robot was presented by the means of the linearization, ignoring the effects of the high-order items and the multiplications of coupling items. And a sliding mode controller...
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