Search results for "Optimal control"
showing 10 items of 209 documents
Developement of new techniques of Optimal Control in Quantum Dynamics : from nuclear magnetic resonance to molecular physics
2011
The goal of this thesis is to apply the optimal control theory to the dynamics of quantum systems.The first part aim at introducing the tools of optimal control in quantum control which were initially developedin mathematics. This approch has been applied on different kinds of quantum system with small and largedimensions. The first part of this manuscript introduces the optimal control tools which are used with a pointof view suited to a public of physicists. In the second part these techniques are used to control the dynamics ofspins in NMR and MRI. The third part deals with the development of new iterative algorithms applied to thecontrol by laser fields of the rotational dynamics of lin…
Motion Cueing Algorithms: A Review
2017
Robotic motion platforms are commonly used in motion-based vehicle simulation. However, the reproduction of realistic accelerations within a reduced workspace is a major challenge. Thus, high-level control strategies commonly referred to as motion cueing algorithms (MCA) are required to convert the simulated vehicle physical state into actual motion for the motion platform. This paper reviews the most important strategies for the generation of motion cues in simulators, listing the advantages and drawbacks of the different solutions. The motion cueing problem, a general scheme and the four most common approaches – classical washout, adaptive washout, optimal control and model predictive con…
On Automaton Recognizability of Abnormal Extremals
2002
For a generic single-input planar control system $\dot x=F(x)+ u G(x),$ $x\in\mathbb{R}^2,$ $u\in [-1,1]$, $F(0)=0$, we analyze the properties of abnormal extremals for the minimum time stabilization to the origin. We prove that abnormal extremals are finite concatenations of bang arcs with switchings occurring on the set in which the vector fields F and G are collinear. Moreover, all the generic singularities of one parametric family of extremal trajectories near to abnormal extremals are studied. In particular, we prove that all possible sequences of these singularities, and hence all generic abnormal extremals, can be classified by a set of words recognizable by an automaton.
Sub-Optimal Control Law for Active Magnetic Bearings Suspension
2012
This paper deals with the comparison of three types of sub-optimal control law for the stable levitation of a turbojet shaft, sustained by two radial active magnetic bearings (AMBs). Shaft is considered rigid for the procedure simplification. The utilized approach leads to development of different sub-optimal control laws to use in speed-varying simulations in the angular speed of the shaft. The first control matrix is obtained by explicit relationships of the parameters of the control law vs. speed, obtained using a curve-fitting procedure neglecting the speed-varying elements out of the main diagonal of each single block constituting the entire control matrix. The second control law is ob…
EXPERIMENTAL INVESTIGATIONS OF MINIMUM POWER CONSUMPTION OPTIMAL CONTROL FOR VARIABLE SPEED AMB ROTOR
2010
The purpose of this paper is to present a method for development of the optimal speed-dependent control matrix for a rotor supported on active magnetic bearings (AMBs) with the provision of minimum control power consumption over the operating speed range. The speed dependency of the optimal control matrix is the result of the dynamics of rotating machines. Most of published works on optimal control use a stationary optimal control matrix derived for the non-rotating system and thus neglecting the effect of gyroscopic phenomena. This paper employs the minimum energy consumption condition to derive the speed varying optimal control for rotating AMB rotor system. In the presented approach the …
Application to an italian distribution system of a multiobjective optimal Volt/VAR control strategy: improvements and management problems
2007
In this paper, the experiences and results deriving from the application of a multiobjective optimal management strategy to a distribution network supplying an area in province of Palermo, Italy, are presented. The adopted strategy allows, through the interventions on the Under Load Tap Changers (ULTC) of the primary substations and on tie-switches, to reduce power losses and improve the voltage profiles. To solve the optimization problem, an evolutionary approach has been adopted; it employs fuzzy logic for an adequate and simultaneous fulfilment of the different objectives. The application section presents a deep technical and economical analysis of the results attained, applying the opti…
Solving some optimal control problems using the barrier penalty function method
2005
In this paper we present a new approach to solve the two-level optimization problem arising from an approximation by means of the finite element method of optimal control problems governed by unilateral boundary value problems. The minimized functional depends on control variables and state variables x. The latter are the optimal solution of an auxiliary quadratic programming problem, whose parameters depend on u.
MICROPROCESSOR-BASED SUBOPTIMAL CONTROL OF CONVERTER-FED HYPO-HYPERSYNCHRONOUS CASCADE DRIVES
1984
This work consists ofi a theoretic and experimental study o£ a possible practical realization oi a micro pro cess or-based control system using a converter-fad hypo-hypersynchronous cascade. drive. Vlrstly, the design o£ a microprocessor-based controller Is carried out considering an approximate mathematical model, linear-type, o& the drive -In question, by using optimal control techniques. Several physical constraints, -buck as -input variables constraints, state variables constraints and processing time. o& microprocessor are taken -into account. The approach followed attorn us to obtain a suboptimal, closed-loop control system. In addition, In order to carry out a more accurate study ofa…
Robust Mean Field Games
2015
Recently there has been renewed interest in large-scale games in several research disciplines, with diverse application domains as in the smart grid, cloud computing, financial markets, biochemical reaction networks, transportation science, and molecular biology. Prior works have provided rich mathematical foundations and equilibrium concepts but relatively little in terms of robustness in the presence of uncertainties. In this paper, we study mean field games with uncertainty in both states and payoffs. We consider a population of players with individual states driven by a standard Brownian motion and a disturbance term. The contribution is threefold: First, we establish a mean field syste…
A Fokker–Planck control framework for multidimensional stochastic processes
2013
AbstractAn efficient framework for the optimal control of probability density functions (PDFs) of multidimensional stochastic processes is presented. This framework is based on the Fokker–Planck equation that governs the time evolution of the PDF of stochastic processes and on tracking objectives of terminal configuration of the desired PDF. The corresponding optimization problems are formulated as a sequence of open-loop optimality systems in a receding-horizon control strategy. Many theoretical results concerning the forward and the optimal control problem are provided. In particular, it is shown that under appropriate assumptions the open-loop bilinear control function is unique. The res…