共查询到20条相似文献,搜索用时 31 毫秒
1.
This paper studies a stabilization problem of polytopically uncertain linear parameter varying systems with input constraints and bounded rates of parameter variations. In the framework of finite receding horizon control (RHC), a system containing “parameter” uncertainties is modified into a system with “parameter-incremental” uncertainties within each horizon. For the system modified in this manner, a robust RHC is designed by solving an optimization problem at each time instant. Based on the feasibility of the problem and the optimality of its solution, the closed-loop system stability is guaranteed. A numerical example is included to illustrate the validity of the results. 相似文献
2.
Ilya V. Kolmanovsky Author Vitae Author Vitae 《Automatica》2006,42(5):841-848
Parameter governors are add-on control schemes that adjust parameters (such as gains or offsets) in the nominal control laws to avoid violation of pointwise-in-time state and control constraints and to improve the overall system transient performance via the receding horizon minimization of a cost functional. As compared to more general model predictive controllers, parameter governors tend to be more conservative but the computational effort needed to implement them on-line can be relatively modest because the few parameters to be optimized remain constant over the prediction horizon. In this paper, we discuss the properties of several classes of parameter governors which have a common property in that the governed parameters do not shift the steady-state equilibrium of the states on which the incremental cost function explicitly depends on. This property facilitates the application of meaningful cost functionals. An example, together with simulation results, is reported to provide additional insights into the operation of the proposed parameter governor schemes. 相似文献
3.
不确定离散系统具有H∞性能界的鲁棒LQG状态反馈控制 总被引:2,自引:0,他引:2
研究了含有范数有界参数不确定线性离散系统具有H∞性能界的鲁棒LQG状态反
馈控制问题,考虑了有限时域时变及无限时域时不变两种情形.所得的控制器对于所有可容
许的参数不确定都能满足给定的H∞性能界,且为最坏情形H∞性能指标提供了一个最优上
界.对于无限时域时不变情形,该控制器还能保证闭环系统渐近稳定.结果仅需求解一含有
一个尺度参数的Riccati方程. 相似文献
4.
Receding horizon output feedback control for constrained uncertain systems using periodic invariance
In this article, we consider a receding horizon output feedback control (RHOC) method for linear discrete-time systems with polytopic model uncertainties and input constraints. First, we derive a set of estimator gains and then we obtain, on the basis of the periodic invariance, a series of state feedback gains stabilising the augmented output feedback system with these estimator gains. These procedures are formulated as linear matrix inequalities. An RHOC strategy is proposed based on these state feedback and state estimator gains in conjunction with their corresponding periodically invariant sets. The proposed RHOC strategy enhances the performance in comparison with the case in which static periodic gains are used, and increases the size of the stabilisable region by introducing a degree of freedom to steer the augmented state into periodically invariant sets. 相似文献
5.
Optimal regulation of stochastically behaving agents is essential to achieve a robust aggregate behavior in a swarm of agents. How optimally these behaviors are controlled leads to the problem of designing optimal control architectures. In this paper, we propose a novel broadcast stochastic receding horizon control architecture as an optimal strategy for stabilizing a swarm of stochastically behaving agents. The goal is to design, at each time step, an optimal control law in the receding horizon control framework using collective system behavior as the only available feedback information and broadcast it to all agents to achieve the desired system behavior. Using probabilistic tools, a conditional expectation based predictive model is derived to represent the ensemble behavior of a swarm of independently behaving agents with multi-state transitions. A stochastic finite receding horizon control problem is formulated to stabilize the aggregate behavior of agents. Analytical and simulation results are presented for a two-state multi-agent system. Stability of the closed-loop system is guaranteed using the supermartingale theory. Almost sure (with probability 1) convergence of the closed-loop system to the desired target is ensured. Finally, conclusions are presented. 相似文献
6.
This paper studies the problem of integrated control in the 2-dimensional (2D) system with parameter uncertainties for batch processes. An integrated iterative learning control (ILC) strategy based on quadratic performance for batch processes is proposed. It realizes comprehensive control by combining robust ILC in batch-axis with model predictive control (MPC) in time-axis. The design of quadratic-criterion-based ILC for the system can be converted into a min-max problem. Then a model predictive controller with time-varying prediction horizon is designed based on a quadratic cost function. For an uncertain model, a novel integrated robust ILC scheme based on a nominal model is further proposed. As a result, the control law of the 2D system can be regulated during one batch, which leads to good tracking performance and strong robustness against the disturbance and the uncertainties. Moreover, the analyses of the convergence and tracking performance are given. The proposed methods are applied to batch reactor, and results demonstrate that the system has good robustness and convergence. This paper provides a new way for batch processes control. 相似文献
7.
Hejia Pan 《International journal of control》2013,86(1):98-113
In this article, we propose a robust depth control design scheme for autonomous underwater vehicles (AUVs) in the presence of hydrodynamic parameter uncertainties and disturbances. The controller is designed via a new indirect robust control method that handles the uncertainties by formulating the uncertainty bounds into the cost functional and then transforming the robust control problem into an equivalent optimal control problem. Both robust asymptotic stability and optimality can be achieved and proved with this new formulation. The θ-D method is utilised to solve the resultant nonlinear optimal control problem such that an approximate closed-form feedback controller can be obtained and thus is easy to implement onboard without intensive computation load. Simulation results demonstrate that robust depth control is accomplished under the system parameter uncertainties and disturbances with small control fin deflection requirement. 相似文献
8.
9.
针对噪声方差不确定的约束系统,讨论了一种鲁棒滚动时域估计(MHE)方法.首先,根据噪声方差不确定模型,找到满足所有不确定性的最小方差上界,在线性矩阵不等式(LMI)框架下求解优化问题,得到近似到达代价的表达形式;然后再融合预测控制的滚动优化原理,把系统的硬约束直接表述在优化问题中,在线优化性能指标,估计出当前时刻系统的状态.仿真时与鲁棒卡尔曼滤波方法进行比较,结果表明了该方法的有效性. 相似文献
10.
本文针对含参数不确定性的多电机驱动系统,提出一种基于最优保性能鲁棒的Funnel控制方法实现系统的规定跟踪性能.该控制方法通过构造Funnel函数对误差系统进行变换,并设计自适应反步控制器保证变换后系统的稳定性即可使跟踪误差的瞬态和稳态响应均被限制在给定的Funnel边界内.然而由于系统中存在的参数不确定性会影响系统的规定控制性能,本文在Funnel控制基础上又设计了最优保性能鲁棒控制器.它是通过将参数不确定性系统的保性能鲁棒控制问题转化为标称系统的最优控制问题,并求解新的黎卡提方程而得到的.因此所设计的控制器不但消除了参数不确定性对系统的影响并且能够使系统的性能指标达到一确定的上界.最后,对四电机驱动系统进行了仿真和实验验证,说明所提出控制方法的有效性. 相似文献
11.
12.
Chih-Lyang Hwang Li-Jui Chang 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2007,37(6):1471-1485
In this paper, a partially known nonlinear dynamic system with time-varying delays of the input and state is approximated by N fuzzy-based linear subsystems described by a state-space model with average delay. To shape the response of the closed-loop system, a set of fuzzy reference models is established. Similarly, the same fuzzy sets of the system rule are employed to design a fuzzy neural-based control. The proposed control contains a radial-basis function neural network to learn the uncertainties caused by the approximation error of the fuzzy model (e.g., time-varying delays and parameter variations) and the interactions resulting from the other subsystems. As the norm of the switching surface is inside of a defined set, the learning law starts; in this situation, the proposed method is an adaptive control possessing an extra compensation of uncertainties. As it is outside of the other set, which is smaller than the aforementioned set, the learning law stops; under this circumstance, the proposed method becomes a robust control without the compensation of uncertainties. A transition between robust control and adaptive control is also assigned to smooth the possible discontinuity of the control input. No assumption about the upper bound of the time-varying delays for the state and the input is required. However, two time-average delays are needed to simplify the controller design: 1) the stabilized conditions for every transformed delay-free subsystem must be satisfied; and 2) the learning uncertainties must be relatively bounded. The stability of the overall system is verified by Lyapunov stability theory. Simulations as compared with a linear transformed state feedback with integration control are also arranged to consolidate the usefulness of the proposed control. 相似文献
13.
Adaptive Robust Self-Balancing and Steering of a Two-Wheeled Human Transportation Vehicle 总被引:1,自引:0,他引:1
Shui-Chun Lin Ching-Chih Tsai Hsu-Chih Huang 《Journal of Intelligent and Robotic Systems》2011,62(1):103-123
This paper presents adaptive robust regulation methods for self-balancing and yaw motion of a two-wheeled human transportation
vehicle (HTV) with varying payload and system uncertainties. The proposed regulators are aimed at providing consistent driving
performance for the HTV with system uncertainties and parameter variations caused by different drivers. By decomposing the
overall system into the yaw motion subsystems and the wheeled inverted pendulum, two proposed adaptive robust regulators are
synthesized to achieve self-balancing and yaw motion control. Numerical simulations and experimental results on different
terrains show that the proposed adaptive robust controllers are capable of achieving satisfactory control actions to steer
the vehicle. 相似文献
14.
Robust adaptive controller with disturbance observer for vehicular radar servo system 总被引:1,自引:0,他引:1
Xia Liu Qi Huang Yong Chen 《International Journal of Control, Automation and Systems》2011,9(1):169-175
In vehicular radar servo system, parameter variations of the executive motor and external disturbance uncertainties have great
effects on the position tracking precision of the system. In this paper, a robust adaptive controller with disturbance observer
is designed for vehicular radar servo system, which combines the merits of disturbance observer, adaptive backstepping method
and sliding mode control. The system is modeled, and a disturbance observer is employed to observe and compensate for the
unknown uncertainties. Adaptive backstepping method is used to design the sliding model controller to guarantee the global
stability of the overall system. Simulation results show that the proposed robust adaptive controller has good performance
in position tracking and enhances the robustness of vehicular radar servo system while observing the uncertainties precisely
and quickly. 相似文献
15.
A robust discrete terminal sliding mode repetitive controller is proposed for a class of nonlinear positioning systems with parameter uncertainties and nonlinear friction. The terminal sliding mode control (TSMC) part is designed to improve the transient characteristics of the system, as well as the robustness against parameter uncertainties, nonperiodic nonlinearities, and disturbances. The repetitive control (RC) part is then integrated to eliminate the effects of the periodic uncertainties present in the system. Moreover, a pure phase lead compensator is incorporated into the RC to improve the tracking at high frequencies. A robust stability analysis and an analysis of the finite time convergence properties of the proposed controller are also provided in this paper. Simulation testing and an experimental validation using a linear actuator system with nonlinear friction and parameter uncertainties are conducted to verify the effectiveness of the proposed controller. 相似文献
16.
Adaptive Sliding Mode Control for Re-entry Attitude of Near Space Hypersonic Vehicle Based on Backstepping Design
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Jingmei Zhang Changyin Sun Ruimin Zhang Chengshan Qian 《IEEE/CAA Journal of Automatica Sinica》2015,2(1):94-101
Combining sliding mode control method with radial basis function neural network (RBFNN), this paper proposes a robust adaptive control scheme based on backstepping design for re-entry attitude tracking control of near space hypersonic vehicle (NSHV) in the presence of parameter variations and external disturbances. In the attitude angle loop, a robust adaptive virtual control law is designed by using the adaptive method to estimate the unknown upper bound of the compound uncertainties. In the angular velocity loop, an adaptive sliding mode control law is designed to suppress the effect of parameter variations and external disturbances. The main benefit of the sliding mode control is robustness to parameter variations and external disturbances. To further improve the control performance, RBFNNs are introduced to approximate the compound uncertainties in the attitude angle loop and angular velocity loop, respectively. Based on Lyapunov stability theory, the tracking errors are shown to be asymptotically stable. Simulation results show that the proposed control system attains a satisfied control performance and is robust against parameter variations and external disturbances. 相似文献
17.
Meng-Bi Cheng Wu-Chung Su Ching-Chih Tsai 《International journal of systems science》2013,44(3):408-425
This article presents a robust tracking controller for an uncertain mobile manipulator system. A rigid robotic arm is mounted on a wheeled mobile platform whose motion is subject to nonholonomic constraints. The sliding mode control (SMC) method is associated with the fuzzy neural network (FNN) to constitute a robust control scheme to cope with three types of system uncertainties; namely, external disturbances, modelling errors, and strong couplings in between the mobile platform and the onboard arm subsystems. All parameter adjustment rules for the proposed controller are derived from the Lyapunov theory such that the tracking error dynamics and the FNN weighting updates are ensured to be stable with uniform ultimate boundedness (UUB). 相似文献
18.
《Automatic Control, IEEE Transactions on》2000,45(9):1749-1755
This paper studies the problem of adaptive control for a class of nonlinear time-varying discrete-time systems with nonparametric uncertainties. The plant parameters considered here are not necessarily slowly time-varying in a uniform way. They are allowed to have a finite number of big jumps. By using the backstepping procedures with parameter projection update laws, a robust adaptive controller can be designed to achieve adaptive tracking of a reference signal for this class of systems. It is shown that the proposed controller can guarantee the global boundedness of the states of the whole adaptive system in the presence of parametric and nonparametric uncertainties. It can also ensure that the tracking error falls within a compact set whose size is proportional to the size of the uncertainties and disturbances. In the ideal case when there is no nonparametric uncertainties and time-varying parameters, perfect tracking can be achieved 相似文献
19.
《Simulation Modelling Practice and Theory》2007,15(7):801-816
In this paper, a stable adaptive fuzzy-based tracking control is developed for robot systems with parameter uncertainties and external disturbance. First, a fuzzy logic system is introduced to approximate the unknown robotic dynamics by using adaptive algorithm. Next, the effect of system uncertainties and external disturbance is removed by employing an integral sliding mode control algorithm. Consequently, a hybrid fuzzy adaptive robust controller is developed such that the resulting closed-loop robot system is stable and the trajectory tracking performance is guaranteed. The proposed controller is appropriate for the robust tracking of robotic systems with system uncertainties. The validity of the control scheme is shown by computer simulation of a two-link robotic manipulator. 相似文献
20.
本文讨论了同时具有结构性和非结构不确定性的系统的鲁棒稳定控制问题。首先考虑输入和输出阵同时存在参数摄动系统的H∞设计方法给出了鲁棒稳定控制问题的一个解。 相似文献