Closed-loop Optimal Control Research Articles

Optimal excitation control for power system stability

A method is presented for finding the closed-loop time optimal excitation control for a power system by applying Pontryagin's minimum principle. Numerical results are presented for single machine-infinite bus problems implementing such control.

Synthesis of Quasi-Optimal Switching Surfaces by Means of Learning Techniques

In this paper a synthesis of quasi-optimal switching surfaces based on the combination of off-line and on-line learning algorithms is presented which achieves a practical realization of the closed loop optimal control law. Briefly the technique includes the following: a. obtaining the open loop optimal control laws through optimization theory for the perfectly known plant conditions. b. Training the incompletely specified actual controller by a combination of on-line and off-line learning techniques. The result from item 2 is a realisation of the closed-loop optimal control law. An application of the previously described procedure to realize the switching surface for a time-optimal temperature control problem is presented in detail.

Pseudo optimal closed loop control of nonlinear systems via a hybrid technique

Pseudo optimal closed loop control of nonlinear systems via a hybrid technique

Dynamic optimization of a steel-making process in electric arc furnace

The paper presents the theoretical basis, technical design, and preliminary experimental results of the dynamic optimal control of a steel-making process in an electric arc furnace. As a performance measure of the process, the unit production cost is assumed to be a combination of the cost of electric energy and the cost of time. A system of ordinary differential equations is taken as the mathematical model of the process. The theoretical problems of process optimization and of control system synthesis is solved by means of the Maximum Principle. It is shown that, with some assumptions, optimum control can be accomplished by means of a peak-holding controller. The technical design of both open- and closed-loop optimal control systems, now being implemented, is based mainly on analogue techniques with respect to both control optimality and a temperature program. The experimental results of the optimal control achieved on the basis of prepared algorithms and presented in the paper confirm theoretical estimations. The possibility of considering an expanded problem nvolving optimization of a number of arc furnaces with respect to joint constraints is also discussed at the end of paper.

Optimal Digital Computer Control of Nuclear Reactors

The use of a digital computer to achieve closed loop optimal control of a nuclear reactor is presented. A performance index is defined, and dynamic programming is applied to derive an optimal stationary feedback control law. The control law requires that all state variables be available, therefore nonlinear estimation is used to generate the nonmeasurable system state variables.

The use of a method of perturbations in the synthesis of closed-loop optimal control laws for non-linear systems

A perturbation method of solving the Hamilton-Jacobi-Bellman partial differential equation for the optimal value function in non-linear control problems and a second order on-line control scheme based on this perturbation series are described. Examples demonstrating the effectiveness of using a truncated control series, obtained by the perturbation method and of using the on-line control scheme are presented.

Formulation of the minimum trajectory sensitivity problem

Two possible ways of introducing a trajectory sensitivity vector into the closed-loop linear optimal control problem, their relationship, and their relative merits are discussed.

Minimum Trajectory Sensitivity of a Large Launch Booster Control System

An optimal closed-loop control scheme is developed for a linear timevarying system. The system has two independent parameters which may deviate from their nominal values. The problem is motivated by the possible failure of the control system of the large launch booster after takeoff. The computational scheme involves an iterative algorithm and requires the solution to a matrix Riccati equation. An example is given as an illustration.

On trajectory sensitivity in optimal control

Available results are summarized on the comparative trajectory sensitivities of nominally equivalent open-loop and closed-loop optimal control systems.

On the comparison of the sensitivities of open-loop and closed-loop optimal control systems

This paper derives, via Pontryagin's minimum principle, the invariance of the sensitivity of cost for optimal systems with respect to open-loop and closed-loop control law implementation when system parameters undergo small variations. The result obtained here is more general than that of Pagurek[1] and somewhat easier to apply than that of Witsenhausen.[2] The cost of the sensitivity vector is simply related to the gradient of the Hamiltonian function.

On optimal closed loop control of a rolling mill

On optimal closed loop control of a rolling mill

The equivalence and approximation of optimal control problems

Discontinuities occurring in closed loop optimal control problems when using maximum principle

On closed-loop optimal control

On closed-loop optimal control

On closed-loop optimal control

On closed-loop optimal control