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1.
This paper addresses the semi-global leader-following coordination problem of general linear multi-agent systems, in which the control input of each agent is steered by aperiodically intermittent saturated actuator. Both the case with only one virtual leader and the case with multiple virtual leaders are discussed. By using multiple Lyapunov stability theory and applying algebraic Riccati equation-based low-gain feedback technique, sufficient conditions guaranteeing semi-global consensus tracking and semi-global containment tracking are provided. Numerical simulations finally verify the theoretical analysis.  相似文献   

2.
This paper researches the finite-time event-triggered containment control problem of multiple Euler–Lagrange systems (ELSs) with unknown control coefficients. To realize an accurate convergence time, the settling-time performance function is employed to ensures the steady-state and dynamic properties of the containment errors in the resulting system. Meanwhile, to handle unknown control coefficients, adaptive neural networks (ANNs) with an additional saturated term are designed, which removes the requirement of full rank control coefficients in traditional control methods. By establishing an event-triggered mechanism, a novel finite-time event-triggered containment control law is designed, which yields the semi-global practical finite-time stable (SGPFS) of the resulting closed-loop system without Zeno phenomenon according to the finite-time stability criterion. The effectiveness of the designed methodology is verified by simulation.  相似文献   

3.
This paper investigates the semi-global cooperative cluster output regulation problem of heterogeneous multi-agent systems with input saturation, the exosystems for each cluster can be different. To avoid using global information (e.g., the minimal nonzero eigenvalue of the Laplacian matrix) in the control protocol, an adaptive dynamic compensator is proposed to estimate exosystem’s state in fully distributed manner. A dynamic event-triggering mechanism with adaptive parameter is proposed in order to reduce the usage of communication resources. Low-gain feedback technique is utilized to deal with the influence of input saturation, and Lypunov-based stability analysis results are obtained. Moreover, it is formally shown that Zeno behavior can be excluded. The superiority of the proposed methods includes: the agents in each cluster are also heterogeneous, which is essentially different from [1]; the event-triggered control strategy does not depend on any global information; and the influence of saturation nonlinearity can be eliminated with low-gain feedback. Finally, a numerical example is provided to illustrate the effectiveness of the proposed methods.  相似文献   

4.
This paper deals with the containment control problem for multi-agent systems with exogenous disturbances. A disturbance observer-based control approach is employed to estimate the disturbances generated by an exogenous system. Consequently, distributed disturbance observer-based containment control protocols are proposed by using the state feedback control and the output feedback control, respectively. Furthermore, with the help of algebraic graph theory and Lyapunov stability theory, sufficient conditions are established to ensure that multi-agent systems with exogenous disturbances can achieve containment control via the disturbance observer-based approach. Finally, the effectiveness of our theoretical results is verified by providing numerical simulation examples.  相似文献   

5.
The bipartite time-varying formation group containment tracking control problem of multi-agent systems with unknown input leader on semi-signed digraph is studied. In this paper, the multi-agent system is divided into three layers: the leader layer with unknown input, the formation layer with cooperative-competitive relationship, and the containment layer without competitive relationship. First, the formation members in formation layer track the state of the leader in the leader layer, to achieve bipartite time-varying formation and form two convex hull. Then, by assuming two subgroups of the containment layer exist a well-informed individual (which can receive corresponding convex hull of all the formation members of communication), respectively, the followers of the two subgroups can not only converge to respectively two convex hulls formed by formation layer, also can make the followers of the same subgroup converge to a common value, this provides a prerequisite for the formation control of the followers in the containment layer. Next, different control protocols are designed for formation layer and containment layer respectively based on neighbor information, and Lyapunov function is constructed to provide stability proof for the realization of the problem. Finally, several simulation results are given to verify the validity of the theory.  相似文献   

6.
Hyper-exponential stability analysis and hyper-exponential stabilization of linear systems by bounded linear time-varying feedback are investigated in this paper. On the one hand, we propose some Lyapunov-like hyper-exponential stability theorems (both global and local) based on the comparison principle and the concepts of hyper-exponentially stable functions and hyper-exponentially increasing functions. On the other hand, we establish methods to design bounded linear time-varying controllers such that hyper-exponential stability of linear time-invariant systems can be guaranteed. The key design tool is the utilization of a time-varying parameter contained in the controller and the properties of solution to a parametric Lyapunov equation. Both state feedback and observer-based output feedback are accommodated. As a further result, hyper-exponential semi-global stabilization for linear systems by bounded controls is discussed. Finally, the validity of the proposed schemes is illustrated through numerical simulations on spacecraft rendezvous control system.  相似文献   

7.
In this paper, an adaptive distributed control protocol is proposed for non-affine multi-agent system with nonlinear dead-zone input and state constraints under the condition of directed topology. In order to overcome the difficulties caused by non-affine terms in the system, the nonlinear dynamics system is transformed. Then, the neural network technology is introduced to approximate the unknown non-affine terms for the obtained system. State constraints and dead-zone input are common system problems. In order to solve these problems, the barrier Lyapunov function is introduced in this paper. According to the barrier Lyapunov function and backstepping method, an adaptive distributed controller is designed, so that state variables do not violate constraint bounds and the system is not affected by dead-zone input. By Lyapunov stability theory, it is proved that the signals of each follower are cooperative semi-global uniform ultimate boundedness (CSUUB), and the outputs of the followers track the output of the leader. Simulation example is given to demonstrate the effectiveness of the proposed method.  相似文献   

8.
This paper studies the neural adaptive control design for robotic systems with uncertain dynamics under the existence of velocity constraints and input saturation. The control objective is achieved by choosing a control Lyapunov function using joint error variables that are restricted to linear growth and furthermore by introducing a secant type barrier Lyapunov function for constraining the joint rate variables. The former is exploited to bind the forward propagation of the position errors, and the latter is utilized to impose hard bounds on the velocity. Effective input saturation is expressed, and neural networks are employed to tackle the uncertainty problem in the system dynamics. Feasibility conditions are formulated, and the optimal design parameters are obtained by solving the constrained optimization problem. We prove that under the proposed method, semi-global uniform ultimate boundedness of the closed-loop system can be guaranteed. Tracking errors meanwhile converge to small neighborhoods of the origin, and violations of predefined velocity constraints are avoided. Finally, numerical simulations are performed to verify the effectiveness of the theoretical developments.  相似文献   

9.
The problem of stabilization of a linear system that is asymptotic null controllable with bounded control is studied in this paper. By combining the parametric Lyapunov equation approach and the gain scheduling technique, a new observer-based output feedback gain scheduling controller is proposed to solve the semi-global stabilization problem for a linear system subject to actuator saturation. By scheduling the design parameters online the convergence rate of the state can be improved. Numerical simulations for a spacecraft rendezvous system show the effectiveness of the proposed approaches.  相似文献   

10.
This paper uses the directed communication topology to investigate the finite-time error constraint containment control for multiple Ocean Bottom Flying Node (OBFN) systems with thruster faults. The OBFN is a benthic Autonomous Underwater Vehicle (AUV), which has been used to explore submarine resources. The model uncertainties, velocity error constraint, external disturbances, and thruster faults of OBFNs motivate the design of containment controller. Moreover, some followers could obtain the states of leader OBFNs. We designed the command filter and the input signal is a hyperbolic tangent function. The virtual velocity error command is generated to follow the velocity error. Then the novel velocity error constraint distributed control algorithm is developed. Furthermore, for the problem of input saturation, by designing a stable anti-saturation compensator, an improved containment algorithm is proposed. It is proved that both the proposed approaches can converge the containment errors towards zero through Lyapunov theory in finite time, which means the followers can reach the convex hull formed by leaders in finite time. Finally, simulation results demonstrate the effectiveness of the two strategies.  相似文献   

11.
This study focuses on the research of the globally asymptotic tracking problem of unknown nonlinear reaction-diffusion equations with time-varying coefficients and uncertain external disturbance. Firstly, fuzzy logic systems and adaptive bounding technique are used to deal with nonlinear reaction-diffusion equations with time-varying coefficients and uncertain external disturbance. Secondly, a novel global state feedback adaptive fuzzy control algorithm is proposed to make the nonlinear reaction-diffusion equations track the target systems globally and asymptotically. In addition, the globally asymptotic tracking condition can be obtained, which overcomes the semi-global results in the existing literatures. Finally, three simulation examples are given to illustrate the feasibility and effectiveness of the proposed control protocols.  相似文献   

12.
This paper mainly focuses on two classes of coordinated tracking problems for networked robotic systems, including semi-global coordinated tracking (SCT) problem and global coordinated tracking (GCT) problem. Considering that the dynamics of the networked robotic system can be unattainable, several novel model-free controller-estimator algorithms are proposed to solve the SCT and GCT problems, as well as to reject the input disturbances contained in the system dynamics. By invoking nonsmooth analysis and Lyapunov argument, a number of novel criteria (including sufficient criteria, necessary and sufficient criteria) for semi-global and global asymptotic stability of the presented algorithms are established. Finally, simulation experiments are carried out to verify the theoretical results.  相似文献   

13.
14.
《Journal of The Franklin Institute》2023,360(14):10681-10705
This paper investigates dynamic event-triggered adaptive leader-following semi-global bipartite consensus (SGBC) of multi-agent systems (MASs) with input saturation. A dynamic event-triggered adaptive control (DETAC) protocol is presented, where the triggering function can regulate its threshold value dynamically. It’s turned out that the SGBC can be achieved via the DETAC protocol under some inequalities. Then, the proposed DETAC protocol is extended to solve bipartite consensus under jointly connected topology. Furthermore, the Zeno behaviors will be avoided. Finally, the rationality of proposed DETAC protocols are tested by simulation results.  相似文献   

15.
In this paper, we first consider the containment control problem of singular heterogeneous multi-agent systems, where all the followers converge to the convex hull spanned by the leaders. To solve this problem, we propose two distributed control laws: one is based on the state feedback control framework, which is suitable for the case that the full state information of each follower is accessible; and the other is based on the output regulation framework, where each follower only can access to its output. Furthermore, the distributed observers are designed for every follower to estimate the convex combination of the leader states which is determined by the communication graph. It should be noted that our results can also regard the non-singular multi-agent systems’ containment control problem as a special case. Finally, simulation results corroborate the effectiveness of our analytical results.  相似文献   

16.
This paper investigates the control-based event-triggered sliding mode control for a networked linear system whose feedback information is transmitted over a digital communication network. In this paper, a novel event-triggered mechanism based on control value is proposed. Different from traditional event-triggered mechanisms that are normally based on states, our mechanism pays more attention to the desired control input value of the system. When the deviation between the current control input and the control input being calculated on the basis of the previous system state exceeds a given threshold, an event is triggered. For the sake of reducing the information to be transmitted, a quantization policy is executed and only a few bits are needed to transmit the feedback symbol of each sample. The combination of the control-based event-triggered mechanism and the quantization policy can significantly reduce both the transmission frequency and the number of bits of each feedback packet. For the concerned system, sliding mode control is implemented. The reachability of the sliding mode surface and the robust stability of the system are analyzed by fully taking quantization effects into account. Moreover, the effects of transmission delay of feedback packets on the event-triggering mechanism are considered. Under the proposed mechanism, the lower bound of event intervals is proven to be non-zero, i.e., the Zeno behavior is excluded. Simulations of a mechanical system are done to further verify the superiority of the proposed mechanism.  相似文献   

17.
This paper proposes an observer-based fuzzy adaptive output feedback control scheme for a class of uncertain single-input and single-output (SISO) nonlinear stochastic systems with quantized input signals and arbitrary switchings. The SISO system under consideration contains completely unknown nonlinear functions, unmeasured system states and quantized input signals quantized by a hysteretic quantizer. By adopting a new nonlinear disposal of the quantized input, the relationship between the control input and the quantized input is established. The hysteretic quantizer that we take can effectively avoid the chattering phenomena. Furthermore, the introduction of a linear observer makes the estimation of the states possible. Based on the universal approximation ability of the fuzzy logic systems (FLSs) and backstepping recursive design with the common stochastic Lyapunov function approach, a quantized output feedback control scheme is constructed, where the dynamic surface control (DSC) is explored to alleviate the computation burden. The proposed control scheme cannot only guarantee the boundedness of signals but also make the output of the system converge to a small neighborhood of the origin. The simulation results are exhibited to demonstrate the validity of the control scheme.  相似文献   

18.
This paper investigates the practical leader-follower formation control issue of underactuated vehicles. To achieve the waypoints-based formation navigation, the autonomous dynamic logic (ADL) guidance is proposed by incorporating the marine practice into the virtual ship-based formation guidance strategy. In the proposed guidance, only a dominant virtual leader is required for constructing the waypoints-based formation reference framework, which shows the simplicity and the practicability. As for the control part, a constrained output feedback algorithm is developed by means of the linear extended state observer (LESO). By constructing the augmented variable, the model uncertainty and unknown disturbances are integrated to be estimated and compensated together. In addition, a second-order dynamic auxiliary system is designed to handle the problem of actuator saturation, where two additional saturation compensation terms are introduced to stabilize the kinematics and the kinetics error dynamics, respectively, and the smoothness of constrained control signals can be guaranteed owing to the modification of Gaussian error function. Using the Lyapunov direct method, all signals in the closed-loop system are proved to be semi-global uniformly ultimately bounded (SGUUB). Finally, two simulation experiments, including the comparative experiment and the formation navigation experiment in the presence of simulated ocean disturbances, are carried out to illustrate the feasibility and the superiority of proposed scheme.  相似文献   

19.
Input shaping provides an effective method for suppressing residual vibration of flexible structure systems. However, it is not very robust to parameter uncertainties and external disturbances. In this paper, a closed-loop input shaping method is developed for suppressing residual vibration of multi-mode flexible structure systems with parameter uncertainties and external disturbances. The proposed scheme integrates both input shaping control and discrete-time neuro-sliding mode output feedback control (NSMOFC). The input shaper is designed for the reference model and implemented outside of the feedback loop to achieve the exact elimination of residual vibration. In the feedback loop, the discrete-time NSMOFC technique is employed to make the closed-loop system behave like the reference model with input shaper, where the residual vibration is suppressed. The selection of switching surface and the existence of sliding mode have been addressed. The knowledge of upper bound of uncertainties is not required. Furthermore, it is shown that increasing the robustness to parameter uncertainties does not lengthen the duration of the impulse sequence. Simulation results demonstrate the efficacy of the proposed closed-loop input shaping control scheme.  相似文献   

20.
This paper investigates the precise containment control problem for nonlinear multi-agent systems (MAS) subject to non-vanishing uncertainties and unknown non-identical control directions under directed communication topology. Due to the existence of the inherent non-vanishing/non-parametric uncertainties and unknown control directions, the precise (zero-error) containment control synthesis becomes nontrivial. The underlying problem becomes even complicated if the convergence rate is required to be pre-specified. This work aims at circumventing the aforementioned difficulties to derive a precise containment control solution. The salient features behind the derived algorithms are: i) the non-vanishing uncertainties are completely rejected; ii) the containment error is regulated to zero at prescribed convergence rate, in spite of the non-vanishing uncertainties and unknown non-identical control directions; and iii) the full-state containment rather than output containment is achieved. A simulation example is given to confirm the effectiveness of the proposed method.  相似文献   

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