This paper extends some of the basic results in the area of Lyapunov (asymptotic) and finite time and practical stability to linear, discrete, time invariant time-delay systems. New definitions have been established f...
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This paper extends some of the basic results in the area of Lyapunov (asymptotic) and finite time and practical stability to linear, discrete, time invariant time-delay systems. New definitions have been established for the latter concept of stability. Sufficient conditions for this type of stability, concerning the particular class of linear discrete time-delay systems are derived. More over the generalization of some previous results, in the area of Lyapunov stability for the same class of systems has been also established and proved.
Si(100)4×3−In reconstruction is essentially a superlattice of magic (identical-size) Si7In6 nanoclusters. Using scanning tunneling microscopy (STM) observations, we have found that under appropriate growth condit...
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Si(100)4×3−In reconstruction is essentially a superlattice of magic (identical-size) Si7In6 nanoclusters. Using scanning tunneling microscopy (STM) observations, we have found that under appropriate growth conditions up to 35% of these clusters can be modified; namely, two Si atoms in the cluster can be replaced by two In atoms, thus forming a Si5In8 cluster. This modification can be considered as a doping of the magic cluster, as it changes the electronic properties of the cluster from semiconducting towards metallic. The doped cluster is less rigid than the ordinary one and swings in the electrical field of the STM tip. The atomic structure and stability of the doped magic cluster have been examined using first-principles total-energy calculations.
By using the result of robust strictly positive real synthesis of polynomial segments for continuous time systems, it is proved that, for any two n-th order polynomials a(z) and b(z), the Schur stability of their conv...
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ISBN:
(纸本)0780379241
By using the result of robust strictly positive real synthesis of polynomial segments for continuous time systems, it is proved that, for any two n-th order polynomials a(z) and b(z), the Schur stability of their convex combination is necessary and sufficient for the existence of an n-th order polynomial c(z) such that c(z)/a(z) and c(z)/b(z) are both strictly positive real. We also provide the construction method of c(z). Illustrative examples are provided to show the effectiveness of this method.
Human's intention plays a key role in human-machine interaction as in the case of a robot serving for a handicapped person. The quality of a service robot will be much enhanced if the robot can infer the human'...
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Human's intention plays a key role in human-machine interaction as in the case of a robot serving for a handicapped person. The quality of a service robot will be much enhanced if the robot can infer the human's intension during the interaction process. In this paper, we propose a soft computing-based technique to read a user's intention using some multisensors-based approach. We have tested the technique by a scenario of 'serving a drink to the user'. With such force/torque or vision sensor, the robot can effectively infer the user's intention to drink the beverage or not to drink. As an application, this intention technique is employed for building a rehabilitation robot, called KARES II, to perform various human-friendly human-robot interaction.
For interval polynomial matrices, we identify the minimal testing set, whose stability can guarantee that of the whole uncertain set. Our results improve the conclusions given by Kamal and Dahleh.
ISBN:
(纸本)0780378962
For interval polynomial matrices, we identify the minimal testing set, whose stability can guarantee that of the whole uncertain set. Our results improve the conclusions given by Kamal and Dahleh.
This paper proposes an autonomous motion controller for mobile robots. It combines a biologically inspired motion planner and a nonlinear feedback controller in order to make a simple and practical motion controller i...
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ISBN:
(纸本)0780377362
This paper proposes an autonomous motion controller for mobile robots. It combines a biologically inspired motion planner and a nonlinear feedback controller in order to make a simple and practical motion controller in natural unknown environments. The motion planner part is designed in the frame of behavior-based scheme and adopts the biological concept "homeostasis". It plays the role of determining desired temporal target posture and modifying controller's gain parameters. The other nonlinear controller part drives the robot to the given target posture from the planner. As a result, the stable nonlinear feedback controller in ideal obstacle free space becomes practical one in natural environments constrained by obstacles. The proposed controller is simple mainly due to its behavior-based characteristics and stable due to the feedback controller considering robot's physical constraints. Simulated results and some experimental feature for autonomous navigation of the differential drive mobile robot, named "MARI", are shown for the present.
The problem of constructing a receding-horizon estimator for nonlinear discrete-time systems affected by disturbances has been addressed. The noises are assumed to be bounded, additive, and acting on both state and me...
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ISBN:
(纸本)0780379241
The problem of constructing a receding-horizon estimator for nonlinear discrete-time systems affected by disturbances has been addressed. The noises are assumed to be bounded, additive, and acting on both state and measurement equations. The estimator is designed according to a sliding-window strategy, i.e., so that it minimizes a receding-horizon estimation cost function. The stability of the resulting filter has been investigated and an upper bound on the estimation error has been found. Such a filter can be suitably approximated by parametrized nonlinear approximators as, for example, neural networks. A min-max algorithm turns out to be well-suited to selecting these parameters, as it allows one to guarantee the stability of the error dynamics of the approximate receding-horizon filter. This estimator is designed off line in such a way as to be able to process any possible information pattern. This enables it to generate state estimates almost instantly with a small on-line computational burden.
A controlsystems engineering approach, employing a two-level overall system architecture and different but compatible formalisms for system representation on the upper and lower levels, has been investigated in detai...
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A controlsystems engineering approach, employing a two-level overall system architecture and different but compatible formalisms for system representation on the upper and lower levels, has been investigated in detail. One design alternative is based on employing fuzzy-system approximators and solving for the adaptive tracking of the given, arbitrary, desired system outputs. The other alternative is based on state equations of composite systems and the use of neural-network approximators to deal with uncertainties and control adaptation. In both alternatives similarity property of subsystems has been exploited. Both designs can be implemented within the standard computer process control technology, and are therefore believed to be promising in applied systems engineering.
The paper first analyses the importance of freeway traffic steam model, then focus on the macroscopic traffic stream model which reflect the relationship between the aggregative traffic variables: traffic density or o...
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ISBN:
(纸本)0780381254
The paper first analyses the importance of freeway traffic steam model, then focus on the macroscopic traffic stream model which reflect the relationship between the aggregative traffic variables: traffic density or occupancy, speed, and flow. Different from the conventional method, principal curves are used to modeling the traffic stream without the assumption of certain function form. Furthermore, we presume that the traffic variables interact with each other and would like to summarize the joint behavior of the traffic variables. After giving a brief description of principal curves and the algorithm is given, experiments in two sets of traffic data were carried out for the comparison of the model accuracy between the proposed model and the classical model proposed by Greenshields. Results show that the accuracy of the proposed model is better than that of the classical model. What is more important, it gives a non-parameter modeling method that may be used as the uniform method for traffic stream modeling as long as enough and accurate traffic data are obtained. The conclusion and further work are outlined in the last section of this paper.
For any two n-th order polynomials a(s) and b(s), the Hurwitz stability of their convex combination is necessary and sufficient for the existence of a polynomial c(s) such that c(s)/a(s) and c(s)/b(s) are both strictl...
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For any two n-th order polynomials a(s) and b(s), the Hurwitz stability of their convex combination is necessary and sufficient for the existence of a polynomial c(s) such that c(s)/a(s) and c(s)/b(s) are both strictly positive real.
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