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...
详细信息
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...
详细信息
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...
详细信息
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...
详细信息
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.
In view of the widespread success of Model Predictive control (MPC), in recent years attention has been paid to its robustness characteristics, either by examining the robustness properties inherent to stabilizing MPC...
详细信息
We propose a graph theory approach for planar autonomous exploration. We first partition the planar space using Peano-Cesaro triangular tiling and then construct an edge adjacency dual graph of the tiling pattern. The...
详细信息
ISBN:
(纸本)9783540743545
We propose a graph theory approach for planar autonomous exploration. We first partition the planar space using Peano-Cesaro triangular tiling and then construct an edge adjacency dual graph of the tiling pattern. The dual graph of the Peano Cesaro triangulation is obtained by defining a vertex for each triangular tile and drawing an edge between two tiles that share an edge. In the presence of obstacles we analyze the subgraph induced by the non-obstacle tiles in the dual graph. We prove the existence of Hamiltonian cycles in this induced subgraph for a certain class of obstacles. We also prove the non-existence of Hamiltonian cycles for certain other obstacle configurations. We present heuristic based algorithms and compare their results for the cases where we have a definitive answer to the existence of Hamiltonian cycles. Examples with figures are included to illustrate the concept.
It has recently been shown that the feedback solution to linear and quadratic constrained Model Predictive control (MPC) problems has an explicit representation as a piecewise linear (PWL) state feedback. For nonlinea...
详细信息
ISBN:
(纸本)9783540726982
It has recently been shown that the feedback solution to linear and quadratic constrained Model Predictive control (MPC) problems has an explicit representation as a piecewise linear (PWL) state feedback. For nonlinear MPC the prospects of explicit solutions are even higher than for linear MPC, since the benefits of computational efficiency and verifiability are even more important. Preliminary studies on approximate explicit PWL solutions of convex nonlinear MPC problems, based on multi-parametric Nonlinear Programming (mp-NLP) ideas show that sub-optimal PWL controllers of practical complexity can indeed be computed off-line. However, for non-convex problems there is a need to investigate practical computational methods that not necessarily lead to guaranteed properties, but when combined with verification and analysis methods will give a practical tool for development and implementation of explicit NMPC. The present paper focuses on the development of such methods. As a case study, the application of the developed approaches to compressor surge control is considered.
Design and control of Power Supplies (PSs) feeding the magnets of a Synchrotron Light Source have to match severe specifications;high accuracy in the range of ppm in output current tracking is required for the correct...
详细信息
ISBN:
(纸本)9783540707004
Design and control of Power Supplies (PSs) feeding the magnets of a Synchrotron Light Source have to match severe specifications;high accuracy in the range of ppm in output current tracking is required for the correct operation of the magnets, while a Power Factor (PF) close to the unit is demanded at the input section due to the high power involved. In this paper an advanced control strategy is presented for a particular kind of Quadrupole Magnet Power Supply, where variable output current has to be imposed. The case of the "switch-mode" multilevel power converter for booster quadrupole magnets of the DIAMOND synchrotron radiation facility under construction at the Harwell Chilton Science Campus, Didcot, has been considered. High accuracy in the tracking of the desired output current reference is reached by means of a digital internal model-based controller. A multivariable controller is adopted in order to ensure current balancing between the stages of the multilevel converter. Front-end topology selection, proper dimensioning and control design are exploited to guarantee high power factor and low harmonic distortion of the input currents, and to avoid low-frequency components related to the quadrupole magnets' oscillating currents. For this purpose, confined oscillatory behavior imposed to the voltage of the DC-link capacitors plays a key role. Simulations and experimental validations are reported that confirm the expected results.
In dynamical processes states are only partly accessible by measurements. Most quantities must be determined via model based state estimation. Since in general only noisy data are given, this yields an ill-posed inver...
详细信息
ISBN:
(纸本)9783540726982
In dynamical processes states are only partly accessible by measurements. Most quantities must be determined via model based state estimation. Since in general only noisy data are given, this yields an ill-posed inverse problem. Observability guarantees a unique least squares solution. Well-posedness and observability are qualitative behaviours. The quantitative behaviour can be described using the concept of condition numbers. which we use to introduce an observability measure. For the linear case we show the connection to the well known observability Gramian. For state estimation regularization techniques concerning the initial data are commonly applied in addition. However, we show that the least squares formulation is well-posed, avoids otherwise possibly occuring bias and that the introduced observability measure gives a lower bound on the conditioning of this problem formulation. Introducing possible model error functions we leave the finite dimensional setting. To analyse in detail the influence of the regularization parameters and of the coefficients of the model, we study, as a start, linear state equations as constraints, which appear nearly always as a subproblem of the nonlinear case. We show that state estimation formulated as optimization problem omitting regularization of the initial data leads to a well-posed problem with respect to L-2(-) and L-infinity(-) disturbances. If the introduced measure of observability is low, the arising condition numbers with respect to the L-2-norm can be arbitrarily large. Nevertheless, for the probably in praxis more relevant L-infinity-norm perturbations yield errors in the initial data bounded independently of the system matrix.
This paper summarizes recent developments and applications of dynamic real-time optimization (D-RTO). A decomposition strategy is presented to separate economical and control objectives by formulating two subproblems ...
ISBN:
(纸本)9783540726982
This paper summarizes recent developments and applications of dynamic real-time optimization (D-RTO). A decomposition strategy is presented to separate economical and control objectives by formulating two subproblems in closed-loop. Two approaches (model-based and model-free at the implementation level) are developed to provide tight integration of economical optimization and control, and to handle uncertainty. Simulated industrial applications involving different dynamic operational scenarios demonstrate significant economical benefits.
暂无评论