Control Of Coupled Systems Research Articles

A Global Optimality Principle for Fully Coupled Mean-field Control Systems

A Global Optimality Principle for Fully Coupled Mean-field Control Systems

Earthquake response control effects of coupled structural systems incorporating a negative stiffness connector: Experimental and numerical investigation

Coupled vibration control (CVC) systems, which typically consist of two frames and connectors, such as stiffness and damping elements, can be used for the seismic protection of coupled or adjacent structures. This study aims to experimentally and numerically elucidate the response behavior and control effects of CVC structural systems comprising a mainframe and subframe incorporating passive negative stiffness (PNS) at the connection subjected to earthquakes. Shake table experiments were conducted using CVC system specimens incorporating a PNS device (PNSD) consisting of curved-leaf springs under dynamic excitations. A significant seismic response reduction for the mainframe of the CVC specimen under simulated waves was achieved by incorporating the PNSD at the connection. Moreover, a response simulation was performed using six-story CVC structure models connected by negative stiffness and viscous damping elements subjected to simulated and observed seismic wave inputs. The displacement and acceleration peak response of the mainframe using the numerical CVC models was lower than that of the uncontrolled model. Therefore, incorporating negative stiffness and viscous damping connectors into CVC systems can reduce the seismic response. This study contributes to the advancement of aseismic technologies for coupled or adjacent buildings utilizing the PNS.

Optimal decay for a wave-heat system with Coleman–Gurtin thermal law

We study the long-term behaviour of solutions to a one-dimensional coupled wave-heat system with Coleman–Gurtin thermal law. Our approach is based on the asymptotic theory of C0-semigroups and recent results developed for coupled control systems. As our main results, we represent the system as a feedback interconnection between the wave part and the Coleman–Gurtin part and we show that the associated semigroup in the history framework of Dafermos is polynomially stable with optimal decay rate t−2 as t→∞. In particular, we obtain a sharp estimate for the rate of energy decay of classical solutions to the problem.

Finite‐time attitude‐orbit integrated tracking control of flexible spacecraft under input saturation

This paper investigates the attitude-orbit integrated modeling and robust control of flexible spacecraft with input saturation. First, the dual-number method is employed to describe the dynamic model of the spacecraft with the flexible appendage. Then, a fast terminal sliding mode control law is designed to stabilize the attitude-orbit control system of the spacecraft. In addition, considering the input saturation, a time-varying siding surface based terminal sliding mode control law is further proposed to solve the design problem. Under the designed control laws, the state trajectories of the attitude-orbit coupled control systems can achieve to be finite-time stable, and the reachability of the proposed sliding surface can be ensured at the same time. Finally, through numerical simulations and comparison with the conventional methods, the superiority of the proposed control strategies in convergence speed and convergence accuracy is verified, and the feasibility of engineering application is verified.

Global asymptotic stability in mean for stochastic complex networked control systems

In this paper, global asymptotic stability in mean (GASM) for stochastic complex networked control systems (SCNCS) is studied. A fresh and suitable global Lyapunov function for SCNCS is constructed based on Kirchhoff’s matrix tree theorem in graph theory. Some sufficient criteria guaranteeing GASM for SCNCS are given, by applying Lyapunov method and stochastic analysis skills. These criteria are closely related to topological structure and coupling form functions of SCNCS. Furthermore, an application to a class of stochastic Lurie coupled control systems on networks (SLCCSN) is provided. Ultimately, a numerical test and its simulation process are presented to explain the validity of our theories.

Stability analysis of T-S fuzzy-model-based coupled control systems with nonlinear T-S fuzzy control and its application

Stability analysis of T-S fuzzy-model-based coupled control systems with nonlinear T-S fuzzy control and its application

Global stability analysis for coupled control systems and its application: Practical aspects and novel control

In this paper, the global stability of coupled control systems (CCSs) is discussed. Assembling the energy of each vertex system with the help of graph theory, a systematic method for constructing a global Lyapunov function of CCSs is proposed. Then, two kinds of stability criteria by Lyapunov-type theorem and coefficient-type theorem with the condition of the system topology are derived. Subsequently, the theoretical results are applied to the microgrid and the criterion of global asymptotical stability of the microgrid is developed. Meanwhile, based on the actual demand of the microgrid, the secondary frequency distributed consistency sliding mode control of the microgrid is proposed using the consensus algorithm. In the presence of a time-varying load, the control can not only quickly stabilize the frequency at the equilibrium point but also dynamically achieve active power sharing. Finally, the simulation of an islanded microgrid is conducted to test the validity and feasibility of our results.

Contention-resolving model predictive control for coupled control systems with a shared resource

Priority-based scheduling strategies are often used to resolve contentions in resource constrained control systems. Such scheduling strategies inevitably introduce time delays into controls and may degrade the performance of control systems. Considering the coupling between priority assignment and control, this paper presents a method to co-design priority assignments and control laws for each control system, which aims to minimize the overall performance degradation caused by contentions. The co-design problem is formulated as a mixed integer optimization problem with a very large search space, rendering difficulty in computing the optimal solution. To solve the problem, we develop a novel contention-resolving model predictive control method to dynamically assign priorities and compute an optimal control. The priority assignment can be determined using a sample-based approach without excessive demand on computing resources, and optimal controls can be computed iteratively following the order of the assigned priorities. We apply the proposed contention-resolving model predictive control to co-design scheduling and controls in networked control systems. We present simulation results to show the effectiveness of our proposed method.

Existence and global exponential stability of periodic solutions for coupled control systems on networks with feedback and time delays

In this paper, the existence and global exponential stability of periodic solutions for coupled control systems on networks with feedback and time delays (CCSFD) are considered. Several sufficient criteria are given to guarantee the existence and global exponential stability of periodic solutions for CCSFD by combining with coincidence degree theory, Lyapunov method, and graph theory. Furthermore, an application to a class of Lurie coupled control systems on networks is presented to show the feasibility of our results. In the end, a numerical test is presented to illustrate the effectiveness of our theoretical results.

Separation in Coupled Event-Triggered Networked Control Systems

Information constraints, for example due to resource limitations, pose a significant challenge for the control of geographically distributed systems. In this work, we investigate the separation of estimation and control in event-triggered discrete-time stochastic systems which are physically interconnected. The information pattern and resource constraints on the system can undermine the separation property and lead to a problem which is difficult to solve. For the class of problems considered, we investigate the constraints and information pattern between the controllers such that separation can be applied in solving the optimal control problem.

Collinear dynamical systems

We introduce and study collinearity as a systems theoretic property, asking whether coupled dynamical systems with collinear initial conditions maintain collinear solutions for all times. Completely characterizing such collinear dynamical systems, we find that they define a Lie algebra whose Lie group are the invertible collinearity-preserving maps. Our characterization of collinear systems then allows us to determine state feedbacks which enforce collinear solutions in coupled control systems. Further, we characterize coupled linear differential equations whose solutions will asymptotically become collinear. Last, we characterize collinearity of multiple dynamical systems and their ability to produce coplanar solutions. Our findings relate to flows on the real projective spaces and Grassmannians.

A graph-theoretic approach to global input-to-state stability for coupled control systems

In this paper, the input-to-state stability for coupled control systems is investigated. A systematic method of constructing a global Lyapunov function for the coupled control systems is provided by combining graph theory and the Lyapunov method. Consequently, some novel global input-to-state stability principles are given. As an application to this result, a coupled Lurie system is also discussed. By constructing an appropriate Lyapunov function, a sufficient condition ensuring input-to-state stability of this coupled Lurie system is established. Two examples are provided to demonstrate the effectiveness of the theoretical results.

On input-to-state stability for stochastic coupled control systems on networks

This paper investigates the input-to-state stability (ISS) properties for stochastic coupled control systems on networks (SCCSNs). With the help of Lyapunov method and graph theory, some inequality techniques and stochastic analysis skills, some sufficient criteria are obtained for eλt-weighted integral ISS in mean and almost sure exponential ISS of SCCSNs. These sufficient criteria are closely related to the topological property of the network anatomy. Finally, an example is given to illustrate the results.

Evaluation System for Autonomous Control Methods in Coupled Planning and Control Systems

Autonomous control is an approach to cope with increasing complexity in production and logistics. Autonomous control methods are characterised by decentralised coordination of logistic objects in a heterarchical organisation structure. Autonomous objects themselves are capable of processing information in order to make and execute decisions on their own. Up to now, research in this field mainly focuses on the effects of autonomous control methods disregarding their integration in existing planning systems. Thereby, it is currently not possible to give a substantiated recommendation, which combination of planning and autonomous control methods achieves a sufficient degree of logistic objective achievement in production systems of different complexity. Existing evaluation systems in the field of autonomous control methods remain on a mainly qualitative level disregarding the planning system. Therefore, this paper presents a quantitative, three-dimensional evaluation system. First, it operationalises the degree of complexity in production systems depending on shop floor conditions and disturbances. Second, the paper operationalises the degree of autonomy of production systems. Thereby, it considers the type and intensity of coupling between the planning and control level. Third, a vector of performance indicators is defined to measure the logistic objective achievement and the degree of plan fulfilment. The result is an evaluation system which allows a complete quantitative evaluation of autonomous control in production systems. Furthermore, the focus of consideration is expanded from the mere control level to the planning and control level. The influence of the strength of coupling between planning and control methods on the autonomy is also taken into account and operationalised. Finally, the evaluation system is exemplarily applied to a published simulation study.

A Switched Approach to Robust Stabilization of Multiple Coupled Networked Control Systems

This paper proposes a switched approach to robust stabilization of a collection of coupled networked controlled systems (NCSs) with node devices acting over a limited communication channel. We suppose that the state information of every subsystem is split into different packets and only one packet of the subsystem can be transmitted at a time. Multiple NCSs with norm-bounded parameter uncertainties and multiple transmissions are modeled as a periodic switched system in this paper. State feedback controllers can be constructed in terms of linear matrix inequalities. A numerical example is given to show that a collection of uncertain NCSs with the problem of limited communication can be effectively stabilized via the designed controller.

Active Control in Vehicles and in the Inner Ear: a Review

The low–frequency sound inside a number of aircraft and cars is now attenuated using commercial active sound– control systems. These operate either using loudspeakers to directly drive the sound field, or with shakers acting on the structure to modify its vibration and, hence, reduce excitation of the sound field. As the structure becomes larger, the number of actuators and sensors required for effective control rises significantly. Conventional, fully coupled control systems then become costly in terms of weight and sensitivity to individual failures. An alternative strategy of distributing the control over multiple local controllers will be discussed, which has been shown to be effective in a number of cases. The workings of the inner ear also provide a remarkable natural example of decentralised active vibration control, which aims to enhance the motion within the cochlea. A simple model for this cochlear amplifier, in which each of the outer hair cells act as local control loops, will be described and its use illustrated in predicting the otoacoustic emissions generated by the ear as a result of this mechanism. These emissions are used clinically to screen the hearing of young children, so it is important to understand how they are generated within the cochlea.

Optimum Gain for Coupled Control Systems

Optimum Gain for Coupled Control Systems