共查询到20条相似文献，搜索用时 15 毫秒
1.
《Journal of The Franklin Institute》2006,343(4-5):480-494
The maximum principle developed by Sloss et al. [Optimal control of structural dynamic systems in one space dimension using a maximum principle, J. Vibr. Control 11 (2005) 245–261] is used to determine the optimal control functions for a class of one-dimensional distributed parameter structures. The distributed parameter structures are governed by systems of fourth order hyperbolic equations with constant coefficients. A quadratic performance index is formulated as the cost functional of the problem and can be used to represent the energy of the structure and the force spent in the control process. The developed maximum principle establishes a theoretical foundation for the solution of the optimal control problem and relates the optimal control vector to an adjoint variable vector. The method of solution is outlined which involves reducing the original problem to a system of ordinary differential equations. The solution of the general problem is given and a structural control problem is solved to illustrate the solution procedure. The effectiveness of the proposed control solution is shown by comparing the behavior of controlled and uncontrolled systems. 相似文献
2.
I.S. Sadek 《Journal of The Franklin Institute》2011,348(7):1656-1667
The present paper deals with an optimal boundary control problem in which the process of systems under consideration is governed by a linear parabolic partial differential equation over an infinite time interval. The objective of the paper is to determine the optimal boundary control that minimize a given energy-based performance measure. The performance measure is specified as a quadratic functional of displacement and a suitable penalty term involving the boundary controls. In order to determine the optimal boundary controls, the problem with boundary controls are converted into a problem with distributed controls. The modal space technique is then used to reduce the system into the optimal control of time invariant lumped parameter system. The associated system of uncoupled first order initial value problems is solved in terms of controllers. Next step deals with the computation of the control and trajectory of the linear time-invariant lumped parameter. For this we approximate the controllers by a finite number of orthogonal exponential zero-interpolants over the interval [0,∞). The resultant performance index after using the optimality condition leads to a system of linear algebraic equations. The suggested technique is easy to implement on digital computer. We provide a numerical example to demonstrate the applicability and efficiency of the proposed approach. 相似文献
3.
Bing Sun 《Journal of The Franklin Institute》2010,347(2):467-482
In this paper, the optimal boundary control for the Kuramoto-Sivashinsky equation is considered. The Dubovitskii and Milyutin functional analytical approach is adopted in investigation of Pontryagin's maximum principles of the system in both fixed and free final horizon cases. The necessary conditions are, respectively, presented for the optimal boundary control problems in these two cases. 相似文献
4.
全球板块运动对板块边界带应力场的影响 总被引：1，自引：0，他引：1
将全球板块边界带分别按照不同的宽度加以界定 ,计算了全球板块边界应力场的长、短波分量 ,讨论了应力场短波分量对观测应力场的相对贡献 ,分析了其与板块边界相互运动类型的相关性 .在收敛型边界带 ,俯冲板片推 (拉 )力是驱动板块运动的主要力源 ,仅仅洋脊推力不能主导板块的应力场形态 ;同时 ,大陆板块之间的碰撞力对板块运动具有重要意义 .计算结果还显示板块边界带参考半宽度以不大于 2 0 0km较为合适 . 相似文献
5.
利用Galerkin有限元方法求解了二维稳态线性对流扩散方程边值问题,采用伴随算子理论进行了相应的误差分析,数值模拟表明该方法的可行性和有效性。 相似文献
6.
This paper presents the optimal regulator for a linear system with time delay in control input and a quadratic cost function. The optimal regulator equations are obtained using the duality principle, which is applied to the optimal filter for linear systems with time delay in observations, and then proved using the maximum principle. Performance of the obtained optimal regulator is verified in the illustrative example against the best linear regulator available for linear systems without delays. Simulation graphs and comparison tables demonstrating better performance of the obtained optimal regulator are included. 相似文献
7.
To perform repetitive tasks, this paper proposes an adaptive boundary iterative learning control (ILC) scheme for a two-link rigid–flexible manipulator with parametric uncertainties. Using Hamilton?s principle, the coupled ordinary differential equation and partial differential equation (ODE–PDE) dynamic model of the system is established. In order to drive the joints to follow desired trajectory and eliminate deformation of flexible beam simultaneously, boundary control strategy is added based on the conventional joints torque control. The adaptive iterative learning algorithm for boundary control scheme includes a proportional-derivative (PD) feedback structure and an iterative term. This novel controller is designed to deal with the unmodeled dynamics and other unknown external disturbances. Numerical simulations are provided to verify the performance of proposed controller in MATLAB. 相似文献
8.
In this paper, the adaptive bilinear control of a first-order 1-D hyperbolic partial differential equation (PDE) with an unknown time-varying source term is investigated where only boundary measurements are available. By means of boundary injection, the bilinear adaptive law is developed in the Lyapunov approach. It consists of a state observer and an input adaptation law combined with a bilinear control method derived using an energy-like principle. Both global asymptotic practical convergence of the tracking error and input-to-state stability of the system are guaranteed. A potential application of this control strategy is the one-loop solar collector parabolic trough where the solar irradiance is the unknown input (source term) and the flow rate is the control variable. The objective is to drive the boundary temperature at the outlet to track a desired profile. Simulation results are provided to illustrate the performance of the proposed method. 相似文献
9.
Kai Liu 《Journal of The Franklin Institute》2018,355(12):4839-4853
In this work, we consider an optimal control problem of a class of stochastic differential equations driven by additive noise with aftereffect appearing in control. We develop a semigroup theory of the driving deterministic neutral system and identify explicitly the adjoint operator of the corresponding infinitesimal generator. We formulate the time delay equation under consideration into an infinite dimensional stochastic control system without time lag by means of the adjoint theory established. Consequently, we can deal with the associated optimal control problem through the study of a Hamilton–Jacob–Bellman (HJB) equation. Last, we present an example whose optimal control can be explicitly determined to illustrate our theory. 相似文献
10.
This paper presents the optimal regulator for a linear system with state delay and a quadratic criterion. The optimal regulator equations are obtained using the maximum principle. Performance of the obtained optimal regulator is verified in the illustrative example against the best linear regulator available for linear systems without delays. Simulation graphs demonstrating better performance of the obtained optimal regulator are included. The paper then presents a robustification algorithm for the obtained optimal regulator based on integral sliding mode compensation of disturbances. The general principles of the integral sliding mode compensator design are modified to yield the basic control algorithm oriented to time-delay systems, which is then applied to robustify the optimal regulator. As a result, the sliding mode compensating control leading to suppression of the disturbances from the initial time moment is designed. The obtained robust control algorithm is verified by simulations in the illustrative example. 相似文献
11.
Aaron D. Schutte 《Journal of The Franklin Institute》2010,347(1):208-227
This paper develops a unified approach for modeling and controlling mechanical systems that are constrained with general holonomic and nonholonomic constraints. The approach conceptually distinguishes and separates constraints that are imposed on the mechanical system for developing its physical structure between constraints that may be used for control purposes. This gives way to a general class of nonlinear control systems for constrained mechanical systems in which the control inputs are viewed as the permissible control forces. In light of this view, a new and simple technique for designing nonlinear state feedback controllers for constrained mechanical systems is presented. The general applicability of the approach is demonstrated by considering the nonlinear control of an underactuated system. 相似文献
12.
This paper addresses the issue of the active vibration control of the transverse modes in a flexible elastic systems. The control is implemented by discrete sets of piezoelectric actuators that apply the optimal forces. The performance index is a time-dependent quadratic functional of state variables and their time derivatives, and control forces which are determined by minimizing the objective functional subject to a penalty term on the control functions. A combination of Galerkin and variational approaches are employed to determine the control forces in the time domain explicitly in terms of coupled amplitudes and velocities. The effectiveness of the proposed method is demonstrated by applying it to a physical problem controlled by piezoelectric patch actuators. 相似文献
13.
进一步讨论了伴随矩阵的秩、可逆性、特征值及一些特殊矩阵的伴随矩阵,并加以证明,力争对伴随矩阵有一个较完整的认识。 相似文献
14.
《Journal of The Franklin Institute》2022,359(11):5512-5532
Unmanned aerial vehicles (UAVs) with limited field of view are utilized to track a moving ground target continuously in urban environment. In urban environment, the sight lines of UAVs to the target are easily blocked by dense obstacles. To overcome this difficulty, the model predictive control (MPC) based collaborative tracking control is proposed with the goal of the maximum visibility of target. First, a visible probability based performance index is proposed, and the flight planning strategy of maximum the phase difference is obtained as a consequence. Then a centralized MPC based collaborative control problem is solved to obtain the optimal control signals. The joint cost function consists of four parts which aims at tracking target, avoiding collision, avoiding the blind area and maintaining the maximum visibility, respectively. The effectiveness of the proposed collaborative strategy is verified by simulation. Compared with the traditional MPC-based collaborative method, the proposed maximum visible probability index provides an optimal dynamic formation structure for multi UAVs to guarantee the tracking of the moving ground target in urban environment. 相似文献
15.
《Journal of The Franklin Institute》2023,360(11):7230-7246
The identification problem of output-error autoregressive (OEAR) systems with scarce measurements is considered in this paper. In order to overcome the massive absence of outputs, an interval-varying recursive identification algorithm is proposed through changing the sampling interval and skipping the missing outputs. Based on the maximum likelihood principle, a maximum likelihood interval-varying recursive least squares algorithm is proposed. The effectiveness of the proposed algorithm is tested by a numerical simulation example, and an application example about the heading motion control of underwater vehicle. 相似文献
16.
陆征一 《中国科学院研究生院学报》1990,(2)
本文利用单调方法、极位原理、Schauder不动点定理、以及常微系统整体稳定的結论,给出一类带Neumann边值条件的半线性反应扩散系统整体正解的存在唯一性及渐近性. 相似文献
17.
[目的/意义]遵循网络舆情演化规律开展高质量的信息治理,是有效化解重大疫情防控中网络舆情事件的必然选择,也是对重大疫情防控精准化、科学化水平的重要检验。[方法/过程]基于弹簧运动的受力原理,借助系统动力学及营力系统理论建构一种“弹簧”动力模型,用以描述信息压力、信息支持力、信息驱动力、信息阻滞力等内外营力的相互作用,以及这些作用力在网络舆情蓄力生成、反弹加速、异化驱动、减速终结等四个动态演进阶段的各自表征。[结果/结论]重大疫情防控中网络舆情的信息治理策略应从前置端口环节守住信息传播“关口”,从中间过程环节打造数字治理格局,从后置反馈环节强化网络舆情监管。 相似文献
18.
The problem of independent force and position control of multitask cooperating manipulators is studied. Each manipulator is in a non-singular configuration and the object can be driven by the contact forces exerted by the end effectors of the manipulators. The design requirement is to control each coordinate of the position of the object as well as each component of the “rest” forces, except the moving forces that are determined uniquely from the object's position. The present design requirement has been proved to be always satisfied together with asymptotic and BIBO stability. A class of controllers solving the above simultaneous problem is analytically determined. The proposed state feedback controller does not depend upon the specific object dynamics and thus the resulting closed-loop multimanipulator system performs as required, not only when handling various objects but also when the dynamics of the objects are unknown or hard to compute or disturbed by external forces. 相似文献
19.
Manipulating flexible objects stirs a great deal of interest due to the potential applications in industry. Most previous research work with multiple manipulators, however, focused on developing control strategies for the manipulation of rigid bodies. This paper seeks to develop simple yet practical and efficient control scheme that enables cooperating arms to handle a flexible beam. Specifically the problem studied herein is that of two arms rigidly grasping a flexible beam and capable of generating forces/moments in such a way as to move a flexible beam along a predefined trajectory. The paper develops a sliding mode control law that provides robustness against model imperfection and uncertainty. It also provides an implicit stability proof. Given the bounds of uncertainty in the model of the flexible beam and choosing a switching surface that enforces trajectory tracking, a control algorithm is designed to push the states to remain on the switching surface. Simulation results for two three joint arms moving a flexible beam are presented to validate the theoretical results. 相似文献
20.
《Journal of The Franklin Institute》2022,359(8):3444-3465
This contribution is concerned with the application of optimal control theories and methods to an ecosystem. There are four major ingredients. The first ingredient is to present an optimal control problem for an ecosystem including infection and competition. The second ingredient is the existence results, which assert that in a given Hilbert space the controlled system admits a unique strong solution and the optimal control problem has at least one optimal pair. The third, which is the main new ingredient of this paper, is a maximum principle for the optimal control problem. The first-order necessary optimality condition for the optimal control is established by employing dual techniques. It provides a theoretical basis for the design of the optimal control strategy. The fourth ingredient is an example and its numerical simulation, which further confirm the results of this paper. 相似文献