Showing papers on "Sliding mode control published in 1974"

Robust solutions to linear multivariable control problems

Abstract: In this paper a special case of the Regulator Problem with Internal Stability (RPIS) [1] is studied from the standpoint of obtaining solutions that are insensitive to perturbations in both the system parameters and the controller gains. The ability to include "robustness" into the problem yields new insight into the role played by dynamic compensation in linear control system synthesis.

Power system excitation and governor design using optimal control theory

Abstract: Integrated excitation and/or governor control systems are the result of using novel approaches for the selection of stabilizing signals in electric power systems. Such controllers have usually been derived on the basis of a linearized system model, an attractive practical feature of these being that a linear, time-invariant optimal controller may be derived. The power system is non-linear, however, and it is for this non-linear system that an optimal controller is ideally required. Previous work in the area is shown to be deficient in the light of this requirement and subsequently time-invariant integrated controllers suitable for use with the non-linear system are developed. These controllers incorporate model following with integral action and are shown to effect improved control of the nonlinear system over a wide range of operating conditions. The manner in which the proposed control system design procedure may permit the integrated control of large power systems is also of considerable pract...

Adaptive dual control for stochastic nonlinear systems with free end-time

Abstract: This short paper discusses the problem of controlling stochastic nonlinear systems where the end-time of the process has to be determined on-line. Since the optimal solution is not obtainable, a dual control method is developed for this class of problems. The algorithm has the property that the control, which is restricted to be causal, utilizes the statistical description of the future observations, i.e., it is of the closed-loop, rather than feedback type. This property allows the controller to enhance the estimation via the dual effect and thus improve the overall performance. The method is illustrated by applying it to an interception problem. Simulation studies on this particular problem provide further insight into how the dual effect of the control can be utilized in nonlinear problems. They also indicate the potential value of the algorithm presented here to practical problems.

Generalization of decoupling control

Abstract: This correspondence develops sufficient conditions for decoupling of an r -input m -output multivariable control system via control law with a rectangular feedforward matrix. A synthesis example of the decoupling control system is given and studied.

Nonlinear systems equivalent to controllable bilinear systems

Abstract: Given a nonlinear analytic control system with an equilibrium point sufficient conditions are given for the existence of a one-to-one transformation to coordinates in which the system becomes bilinear, and an explicit construction is given

A conjugate point condition for control problems with delayed state vectors

Abstract: The new result presented is a conjugate point condition for an optimal control problem in which there is a constant delay in the state vector. The proof is outlined, and the solution method and a differential game application are discussed.

A note on the inverse optimal control of nonlinear systems

Abstract: A procedure for the selection of a nonlinear feedback law has been suggested by Thau as a part of his study on the inverse optimal control problem of nonlinear systems In this note we suggest an alternative feedback law which turns out to be better, in the sense that the transient response improved and at the same time the control energy requirement is reduced

Optimal angular velocity control with finite terminal time for an asymmetric spacecraft

Abstract: A method is presented to obtain optimal feedback control laws to reduce the angular momentum of a tumbling asymmetric spacecraft to rest within a finite interval of time. This correspondence only treats the case with unconstrained but finite continuous control functions.

Optimal control of neutral systems

Abstract: This correspondence considers the necessary conditions for optimal control of a nonlinear neutral system with general cost function. Using variational techniques, it is shown that the adjoint variable is discontinuous, and furthermore, the form of the discontinuity is characterized.