In this paper, a moving horizon state estimation scheme is proposed. The scheme is inspired by combining the system-theoretic concept of observability maps with optimization-based estimators. As a result, a simple mov...
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ISBN:
(纸本)3540279385
In this paper, a moving horizon state estimation scheme is proposed. The scheme is inspired by combining the system-theoretic concept of observability maps with optimization-based estimators. As a result, a simple moving horizon state estimator scheme for nonlinear discrete time control systems is established which guarantees global convergence tinder certain observability conditions.
This paper summarizes two recently presented strategies based oil bifurcation theory and nonlinear dynamics that address robust control design of nonlinear systems. The first strategy applies numerical bifurcation ana...
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ISBN:
(纸本)3540279385
This paper summarizes two recently presented strategies based oil bifurcation theory and nonlinear dynamics that address robust control design of nonlinear systems. The first strategy applies numerical bifurcation analysis to the robust controller timing Of uncertain nonlinear systems. Continuation in the controller and system parameters is used to compute stability boundaries for the controller tuning parameters. Restrictions oil the controller tuning are determined that must hold to guarantee stability for the complete operating range of the closed loop system. The second strategy, the recently presented optimization-based Constructive Nonlinear Dynamics (CNLD) extends ideas from nonlinear dynamics and bifurcation theory to address the synthesis rather than analysis problems. CNLD is based on constraints that enforce a minimal back off from critical manifolds. Critical manifolds axe boundaries in the space of system and controller parameters that separate regions with qualitatively different system behavior, e.g. a region with stable operating points from a region with unstable system behavior. The generality of the concept of critical manifolds permits to address feasibility, stability and performance of a nonlinear (closed-loop) system. The back off from the critical manifolds admits to robustly account for parametric uncertainty during the design step and to guarantee the operability of the optimal solution. For closed-loop systems the approach admits simultaneous plant;and control system design. This work summarizes the background and the basic ideas of both approaches. The application to robust nonlinear control design is illustrated by several case studies.
In this paper we extend the notion of convergent systems defined by B.P. Demidovich and introduce the notions of uniformly, exponentially convergent and input-to-state convergent systems. Basic (interconnection) prope...
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ISBN:
(纸本)3540279385
In this paper we extend the notion of convergent systems defined by B.P. Demidovich and introduce the notions of uniformly, exponentially convergent and input-to-state convergent systems. Basic (interconnection) properties of such systems are established. Sufficient conditions for input-to-state convergence are presented. For a class of nonlinear systems we design (output) feedback controllers that make the closed-loop system input-to-state convergent;. The conditions for such controller design are formulated in terms of LMIs.
We consider the observer design problem for nonlinear single output systems. In contrast to most well-known design procedures the observability matrix may have a rank deficiency. The observer design is based on a part...
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ISBN:
(纸本)3540279385
We consider the observer design problem for nonlinear single output systems. In contrast to most well-known design procedures the observability matrix may have a rank deficiency. The observer design is based on a partial observer form. The proposed observer is a generalization of the extended Luenberger observer. The observer gain can easily be computed.
Lightweight structures typically have low inherent structural damping. Effective vibration suppression is required, for example, in certain applications involving precision positioning. The present approach is based o...
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ISBN:
(纸本)3540279385
Lightweight structures typically have low inherent structural damping. Effective vibration suppression is required, for example, in certain applications involving precision positioning. The present approach is based on friction damping in semi-active joints which allow relative sliding between the connected parts. The energy dissipation due to interfacial slip in the friction joints can be controlled by varying the normal pressure in the contact;area using a piezo-stack actuator. This paper focuses on the optimal placement of semi-active joints for vibration suppression. The proposed method uses optimality criteria for actuator and sensor locations based on eigenvalues of the controllability and observability gramians. Optimal sensor/actuator placement;is stated as a nonlinear multicriteria optimization problem with discrete variables and is solved by a, stochastic search algorithm. At optimal locations, conventional rigid connections of a, large truss structure are replaced by semi-active friction joints. Two different, concepts for the control of the normal forces in the friction interfaces are implemented. In the first approach, each semi-active joint has its own local feedback controller, whereas the second concept uses a global, clipped-optimal controller. Simulation results for a 1.0-bay truss structure show the potential of the proposed semi-active concept.
A new approach is presented for the feedforward control design of nonlinear SISO systems with the application to finite-time setpoint transitions under input constraints. The inversion-based design treats the transiti...
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ISBN:
(纸本)3540279385
A new approach is presented for the feedforward control design of nonlinear SISO systems with the application to finite-time setpoint transitions under input constraints. The inversion-based design treats the transition task as a two-point boundary value problem (BVP) defined in the input-/output coordinates of the considered system. Per its solvability, free parameters are provided in a set-up function for the right-hand side of the input-output;dynamics ODE. This concept allows to directly incorporate input constraints within the BVP, which can be solved in a straightforward manner, e.g. with a standard MATLAB function. Furthermore, an approach is proposed for the design of the transition time in dependence of a desired aggressiveness of the feedforward control. The side-stepping maneuver of the inverted pendulum on a, cart serves as an example to illustrate the concept.
With the sustained increase of air traffic leading to airspace saturation, new flight maneuvering capabilities are expected for commercial aircraft. Among these, relative guidance of airliners, a set of maneuvers that...
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ISBN:
(纸本)3540279385
With the sustained increase of air traffic leading to airspace saturation, new flight maneuvering capabilities are expected for commercial aircraft. Among these, relative guidance of airliners, a set of maneuvers that doesn't require air traffic control support, appears as a. promising solution to ease air traffic controllers' workload. Relative guidance means path convergence of following aircraft to delayed position of leading ones and station keeping The convergence and station keeping phases are realized onboard the aircraft using their sensing and communication facilities, in a decentralized way, under aircraft maneuverability constraints due to safety and passenger comfort issues. Tu this paper, after introducing the relative positioning dynamics of two aircraft,, their flatness property is shown and a flat control law is proposed. Reference trajectories are designed in two steps: if the separation between aircraft is too small, the follower's trajectory is stretched by imposing a sinusoidal movement;at constant speed;in the opposite case, the follower copies the leader's delayed trajectory. The feedback tracking is done by feedback linearization. Simulation results, using a real scenario involving wide body aircraft in a merging situation are displayed and discussed.
In this paper we discuss the existence and non-existence of limit cycles of FitzHugh-Nagumo class models. The purpose is to clarify some unclear facts in the literature. We show also that this class of model exhibits ...
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ISBN:
(纸本)3540239537
In this paper we discuss the existence and non-existence of limit cycles of FitzHugh-Nagumo class models. The purpose is to clarify some unclear facts in the literature. We show also that this class of model exhibits double cycle bifurcation in addition to Andronov-Hopf bifurcation.
This paper deals with the dynamics of hybrid systems under piecewise open-loop controls restricted by hard bounds. The system equations may be reset when crossing some prespecified domains ("the guards") in ...
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ISBN:
(纸本)3540239537
This paper deals with the dynamics of hybrid systems under piecewise open-loop controls restricted by hard bounds. The system equations may be reset when crossing some prespecified domains ("the guards") in the state space. Therefore the continuous dynamics which govern the motion between the guards are complemented by discrete transitions which govern the resets. A state space model for such systems is proposed and reachability sets for such models are described. The computational side of reachability is treated through ellipsoidal techniques that indicate: routes for numerical algorithms.
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