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Adaptive Algorithms for Optimal Control of TimeDependent Partial DifferentialAlgebraic Equation Systems
"... This paper describes an adaptive algorithm for optimal control of timedependent partial differential algebraic equation (PDAE) systems. A direct method based on a modified multiple shooting type technique and sequential quadratic programming (SQP) is used for solving the optimal control problem, ..."
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This paper describes an adaptive algorithm for optimal control of timedependent partial differential algebraic equation (PDAE) systems. A direct method based on a modified multiple shooting type technique and sequential quadratic programming (SQP) is used for solving the optimal control problem, while an adaptive mesh refinement (AMR) algorithm is employed to dynamically adapt the spatial integration mesh. Issues of coupling the AMR solver to the optimization algorithm are addressed. For timedependent PDAEs which can benefit from the use of an adaptive mesh, the resulting method is shown to be highly efficient.
Digital Filter Stepsize Control of DASPK and its Effect on Control Optimization Performance, M.Sc. Thesis
 M.Sc. Thesis, UCSB, 2004
, 2004
"... It has long been known that the solutions produced by adaptive solvers for ordinary differential (ODE) and differential algebraic (DAE) systems, while generally reliable, are not smooth with respect to perturbations in initial conditions or other problem parameters. Söderlind and Wang [12, 13] have ..."
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It has long been known that the solutions produced by adaptive solvers for ordinary differential (ODE) and differential algebraic (DAE) systems, while generally reliable, are not smooth with respect to perturbations in initial conditions or other problem parameters. Söderlind and Wang [12, 13] have recently developed a digital filter stepsize controller that has a theoretical basis from control and appears to result in a much smoother dependence of the solution on problem parameters. This property seems particularly important in the control and optimization of dynamical systems, where the optimizer is generally expecting the DAE solver to return solutions that vary smoothly with respect to the parameters. We have implemented the digital filter stepsize controller in the DAE solver DASP K3.1, and used the new solver for the optimization of dynamical systems. The improved performance of the optimizer, as a result of the new stepsize controller, is demonstrated on a biological problem regarding the heat shock response of Escherichia coli. ∗This work was supported by DOE DEFG0300ER25430, NSF/ITR ACI0086061, NSF CTS
Dynamic Optimization Of Chemically Reacting Stagnation Flows
"... This paper presents a dynamicoptimization algorithm that can be used ..."
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This paper presents a dynamicoptimization algorithm that can be used
Discrete Mechanics and Optimal . . .
, 2007
"... This paper formulates the dynamical equations of mechanics subject to holonomic constraints in terms of the states and controls using a constrained version of the Lagranged’Alembert principle. Based on a discrete version of this principle, a structure preserving timestepping scheme is derived. It ..."
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This paper formulates the dynamical equations of mechanics subject to holonomic constraints in terms of the states and controls using a constrained version of the Lagranged’Alembert principle. Based on a discrete version of this principle, a structure preserving timestepping scheme is derived. It is shown that this respect for the mechanical structure (such as a reliable computation of the energy and momentum budget, without numerical dissipation) is retained when the system is reduced to its minimal dimension by the discrete null space method. Together with initial and final conditions on the configuration and conjugate momentum, the reduced timestepping equations serve as nonlinear equality constraints for the minimisation of a given cost functional. The algorithm yields a sequence of discrete configurations together with a sequence of actuating forces, optimally guiding the system from the initial to the desired final state. The resulting discrete optimal control algorithm is shown to have excellent energy and momentum properties, which are illustrated by two specific examples, namely reorientation and repositioning of a rigid body subject to external forces and the reorientation of a rigid body with internal momentum wheels.
OPTIMIZATION OF SPACECRAFT TRAJECTORIES: A METHOD COMBINING INVARIANT MANIFOLD TECHNIQUES AND DISCRETE MECHANICS AND OPTIMAL CONTROL
"... A mission design technique that uses invariant manifold techniques together with the optimal control algorithm DMOC produces locally optimal, low ∆V trajectories. Previously, invariant manifolds of the planar circular restricted three body problem (PCR3BP) have been used to design trajectories with ..."
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A mission design technique that uses invariant manifold techniques together with the optimal control algorithm DMOC produces locally optimal, low ∆V trajectories. Previously, invariant manifolds of the planar circular restricted three body problem (PCR3BP) have been used to design trajectories with relatively
Proceedings of the Federated Conference on Computer Science and Information Systems pp. 477–484
"... A modified multipoint shooting feasibleSQP method for optimal control of DAE systems ..."
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A modified multipoint shooting feasibleSQP method for optimal control of DAE systems
KEYFRAME CONTROL OF FLUID SIMULATION USING SKELETAL PARTICLES
"... Using physically based simulation to create fluid animation has widely been exploited in computer graphics community for several decades since the plausible fluid animation can not be created solely by means of conventional animation techniques. For computer graphics applications, however, existing ..."
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Using physically based simulation to create fluid animation has widely been exploited in computer graphics community for several decades since the plausible fluid animation can not be created solely by means of conventional animation techniques. For computer graphics applications, however, existing mathematical models from the field of computational fluid dynamics are too computationally intensive and timeconsuming. Due to the fact that highly accurate results are not crucial in visualizing computergenerated fluids, any modifications can be done to achieve the acceptable visual realism using less computational time. Many developments have been purposed to model fluid simulation for computer graphics applications. However, there still has the need in a robust, flexible and controllable model for artistic purposes since animators want to be able to specify the type of effects and control the simulation to reach their goals in interactive time. Nowadays, this problem remains challenging and is continuously gaining the attention among computer graphics researchers. In this research, we propose the novel technique to model a controllable fluid simulation
National Nuclear Security Administration under Contract DEAC0494AL85000.
, 2010
"... Sandia is a multiprogram laboratory operated by Sandia Corporation, ..."
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"... www.elsevier.com/locate/automatica Halo orbit mission correction maneuvers using optimal control � ..."
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www.elsevier.com/locate/automatica Halo orbit mission correction maneuvers using optimal control �