We revisit the deterministic subspace identification methods for discrete-time LTI systems, and show that each column vector of the L-matrix of the LQ decomposition in MOESP and N4SID methods is a pair of input-output...
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ISBN:
(纸本)9783540735694
We revisit the deterministic subspace identification methods for discrete-time LTI systems, and show that each column vector of the L-matrix of the LQ decomposition in MOESP and N4SID methods is a pair of input-output vectors formed by linear combinations of given input-output data. Thus, under the assumption that the input is persistently exciting (PE) of sufficient order, we can easily compute zero-input and zero-state responses by appropriately dividing given input-output data into past and future in the LQ decomposition. This reveals the role of the LQ decomposition in subspace identification methods. Also, a related issue in stochastic realization is briefly discussed in Appendix.
Welding pool deformation has a close relationship with the backside bead width, so pool surface shape sensing is used to monitoring and control weld quality, specifically of weld penetration. In this paper, several th...
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ISBN:
(纸本)9783540733737
Welding pool deformation has a close relationship with the backside bead width, so pool surface shape sensing is used to monitoring and control weld quality, specifically of weld penetration. In this paper, several three-dimensional (3D) reconstruction techniques is analyzed, which were used to reconstruct 3D shape of welding pool. The direct method obtain clear image of pool, so the reconstruction accurate is high. As an indirect method, three SFS algorithms are implemented. Some improved measures are: modeling welding reflection map;new constraint equations;image pretreatment. 3D shape of welding pool was reconstructed and validating results showed this technique can be applied practically.
A wide angle-of-view far infrared (FIR) system based on the method of optical path rotation is presented. The system integrated one FIR camera and one rotating Gold-sprayed mirror controlled by one stepping motor. The...
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ISBN:
(纸本)9783540733737
A wide angle-of-view far infrared (FIR) system based on the method of optical path rotation is presented. The system integrated one FIR camera and one rotating Gold-sprayed mirror controlled by one stepping motor. The FIR camera takes image sequence from the rotating mirror in the real-time monitor. Meanwhile, the speed of pixel movement on the FIR imaging plane is analyzed to obtain the rapidest data acquisition without motion blur. Besides, the view range of the proposed system is considered. Then, the prototype has been designed according to the results of simulation. The experiment data has verified the theory of motion blur. This thermal imaging technique is complexless, noninvasive and feasible for many fields involving the automatic temperature acquisition module.
This paper studies canonical operators on finite graphs, with the aim of characterizing the toolbox of linear feedback laws available to control networked dynamical systems.
ISBN:
(纸本)9783540735694
This paper studies canonical operators on finite graphs, with the aim of characterizing the toolbox of linear feedback laws available to control networked dynamical systems.
In this paper a new distance on the set of multivariate Gaussian linear stochastic processes is proposed based on the notion of mutual information. The definition of the distance is inspired by various properties of t...
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ISBN:
(纸本)9783540735694
In this paper a new distance on the set of multivariate Gaussian linear stochastic processes is proposed based on the notion of mutual information. The definition of the distance is inspired by various properties of the mutual information of past and future of a stochastic process. For two special classes of stochastic processes this mutual information distance is shown to be equal to a cepstral distance. For general multivariate processes, the behavior of the mutual information distance is similar to the behavior of an ad hoc defined multivariate cepstral distance.
We present a new coordinated control law for a group of vehicles in the plane that stabilizes an arbitrary desired group shape. The control law is derived for an arbitrary shape using models of tensegrity structures w...
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ISBN:
(纸本)9783540738893
We present a new coordinated control law for a group of vehicles in the plane that stabilizes an arbitrary desired group shape. The control law is derived for an arbitrary shape using models of tensegrity structures which are spatial networks of interconnected struts and cables. The symmetries in the coupled system and the energy-momentum method are used to investigate stability of relative equilibria corresponding to steady translations of the prescribed rigid shape.
This chapter considers the cooperative control of aerial munitions during the attack phase of a mission against ground targets. It is assumed that sensor information from multiple munitions is available to refine an e...
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ISBN:
(纸本)9783540743545
This chapter considers the cooperative control of aerial munitions during the attack phase of a mission against ground targets. It is assumed that sensor information from multiple munitions is available to refine an estimate of the target location. Based on models of the munition dynamics and sensor performance, munition trajectories are designed that enhance the ability to cooperatively estimate the target location. The problem is posed as an optimal control problem using a cost function based on the variances in the target-location estimate. These variances are computed by fusing the individual munition measurements in a weighted least squares estimate. Numerical solutions are found for several examples both with and without considering limitations on the munitions' field of view. These examples show large reductions in target-location uncertainty when these trajectories are used compared to other naively designed trajectories. This reduction in uncertainty could enable the attack of targets with greater precision using smaller, cheaper munitions.
In this paper, a new contractive receding horizon scheme is proposed for the stabilization of constrained nonlinear systems. The proposed formulation uses a free finite prediction horizon without explicit use of a con...
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ISBN:
(纸本)9783540726982
In this paper, a new contractive receding horizon scheme is proposed for the stabilization of constrained nonlinear systems. The proposed formulation uses a free finite prediction horizon without explicit use of a contraction stability constraint. Another appealing feature is the fact that the resulting receding horizon control is in pure feedback form unlike existing contractive schemes where open-loop phases or a memorized threshold are used to ensure the contraction property in closed loop. The control scheme is validating on the swing-up and stabilization problem of a simple and a double inverted pendulums.
We offer an alternative way of evaluating the relative importance of the state coordinates of a nonlinear control system. Our approach is based on making changes of state coordinates to bring the controllability and o...
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ISBN:
(纸本)9783540707004
We offer an alternative way of evaluating the relative importance of the state coordinates of a nonlinear control system. Our approach is based on making changes of state coordinates to bring the controllability and observability functions into input normal form. These changes of coordinates are done degree by degree and the resulting normal form is unique through terms of degree seven.
作者:
Pham, Khanh D.USAF
Res Lab Space Vehicles Directorate Kirtland AFB NM 87117 USA
This chapter presents an extension of cost-cumulant control theory over a finite horizon for a class of stochastic zero-sum differential games wherein the evolution of the states of the game in response to decision st...
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ISBN:
(纸本)9783540743545
This chapter presents an extension of cost-cumulant control theory over a finite horizon for a class of stochastic zero-sum differential games wherein the evolution of the states of the game in response to decision strategies selected by two players from sets of admissible cone trols is described by a stochastic linear differential equation and a standard integral-quadratic cost. A. direct dynamic programming approach for the Mayer optimization problem is used to solve for a multi-cumulant based solution when both players measure the states and minimize the first finite number of cumulants of the standard integral-quadratic cost associated with this special class of differential games. This innovative decision-making paradigm is proposed herein to provide not only a mechanism in which the conflicting interests of noncooperative players can be optimized, but also an analytical tool which is used to provide a complete statistical description of the global performance of the stochastic differential game.
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