Showing papers on "Sliding mode control published in 1979"
TL;DR: Using block-pulse functions, a method to determine the piecewise constant feedback controls for a finite linear optimal control problem of a power system is presented in this article, which is simple and computationally advantageous.
Abstract: Using block-pulse functions, a method is presented to determine the piecewise constant feedback controls for a finite linear Optimal control problem of a power system. The method is simple and computationally advantageous.
42 citations
TL;DR: In this article, it is shown that rise fixed modes of an interconnected dynamical system under decentralized control are precisely the uncontrollable and unobservable states of individual system components, and these conditions are equivalent to the conditions for stabilizing the system using a global controller.
Abstract: It is shown that rise fixed modes of an interconnected dynamical system under decentralized control are precisely the uncontrollable and unobservable states of the individual system components. As such, the system can be stabilized by decentralized controllers if and only if its individual system components can be stabilized. Moreover, these conditions are shown to be equivalent to the conditions for stabilizing the system using a global controller.
42 citations
TL;DR: This paper presents a method of formal linearization by augmenting state variables for nonlinear systems by introducing a sequence of linearly independent functions and regarding each of them as a new state variable.
Abstract: This paper presents a method of formal linearization by augmenting state variables for nonlinear systems. Introducing a sequence of linearly independent functions and regarding each of them as a new state variable, the original nonlinear system is transformed into an augmented linear system. Based on this linearization, the paper also derives an observer and a suboptimal controller for nonlinear systems. The examples indicate that the linearization has excellent characteristics and greatly improves the performances.
39 citations
TL;DR: In this article, the application of singular perturbation methods to optimal thrust magnitude control (TMC) and optimal lift control in flight mechanics is discussed. But the model is restricted to horizontal plane dynamics.
Abstract: This paper illustrates the application of singular perturbation methods to optimal thrust magnitude control (TMC) and optimal lift control in flight mechanics. The modeling is restricted to horizontal plane dynamics. A multiple time scale analysis results in nonlinear feedback control solutions for lift and thrust during a turn to a specified down range position. The analysis is carried out to rust order with respect to the position state variables. Numerical results for a medium range and a short range air-launched missile are given, and comparisons are made to two alternative propulsion control concepts. The multiple time scaling procedure used here is applicable to solving a wide class of optimal control problems. It avoids the problem in asymptotic methods of picking the unknown adjoints to suppress unstable modes in the boundary layer and reduces the two-point boundary value problem to a series of pointwise function extremizations. Hence, the optimal control solution is essentially analytic and algebraic.
35 citations
TL;DR: In this article, the authors proposed a sliding mode control scheme in which the controller causes the system to follow a prescribed straight-line path in phase space, by applying two different control laws on opposite sides of this switching line, the system is said to be in sliding mode between the two individual laws.
Abstract: In real applications, many devices are highly nonlinear and are difficult to control effectively. Variabilities within the systems and strong external influences make the problem more difficult. One example is the control of electric motors driving elements of a mechanical linkage system such as in an industrial manipulator. By adding a microprocessor to the system, however, the system can be made to operate as if it was linear with a time constant determined by the designer. A method of thus linearizing the system is the so-called ``sliding mode'' control scheme in which the controller causes the system to follow a prescribed straight-line path in phase space. By applying two different control laws on opposite sides of this switching line, the system is said to be in ``sliding'' mode between the two individual laws. Advantages of the method include insensitivity to plant parameter variations, applicability to highly nonlinear systems, and simplicity.
33 citations
01 Sep 1979
TL;DR: In this paper, it was shown that the error associated with the Burg frequency estimator for a truncated real sinusoid in noise can be reduced by using a simple window function in the computation of the coefficient a mm in the mth-order prediction error filter (1, a m1,..., a mm ).
Abstract: It is indicated that the error associated with the Burg frequency estimator for a truncated real sinusoid in noise can be reduced on using a simple window function in the computation of the coefficient a mm in the mth-order prediction-error filter (1, a m1 ,..., a mm ).
32 citations
01 Oct 1979
TL;DR: In this paper, a bang-bang load frequency control policy based on the second method of Lyapunov was proposed for a two-area load-frequency control system, which is simple and practically feasible for implementation.
Abstract: This letter reports a bang-bang load frequency control policy based on the second method of Lyapunov. The proposed method is simple and practically feasible for implementation. A numerical illustration on a two-area load frequency control system is presented in order to verify the practicality of the proposed method.
20 citations
Journal Article•
3 citations
01 Dec 1979
TL;DR: The rationale behind such an assignment and the resulting implications on adaptive control of non-mimimum phase systems are discussed.
Abstract: In adaptive control, 3 orders are relevant. These are the system order, model order and controller order. In much of control theory and identification, the system and model orders are assumed to be equal. However, in principle, it would be possible to independently assign the order of the system, model and controller. This paper discusses the rationale behind such an assignment and the resulting implications. A new result on adaptive control of non-mimimum phase systems will also be presented.
3 citations
TL;DR: On-line optimization of a complex system subject to disturbances is considered and a hierarchical control structure is described, which uses feedback from the controlled system along with simplified mathematical models.
Abstract: In this paper on-line optimization of a complex system subject to disturbances is considered. A hierarchical control structure is described, which uses feedback from the controlled system along with simplified mathematical models. Operation of the control structure is analyzed for the case of time-varying disturbances. The effect of model-reality differences and delays caused by computation and communication is investigated. Theoretical considerations are illustrated by a simulation study.
3 citations
TL;DR: In this article, the design of an optimal controller for a linear single-input system to provide at least a degree α of system stability,2 that is Re (π) < −α, is considered.
Abstract: The design of an optimal controller for a linear single-input system to provide at least a degree α of system stability,2 that is Re (π) < −α, is considered. It is illustrated that such a method may be used to shift only the dominant eigenvalues of a power system to the left of the complex plane
TL;DR: In this paper, the problem of synthesizing control policies that ensure a good steady-state behavior for single-input time-invariant continuous time production-inventory systems is treated, which involves generation of the input vector of a system by linear feedback of the state vector so that the eigenvalues of the closed-loop system are assigned prescribed values.
TL;DR: In this paper, a nonlinear problem of moments, encountered in control of distributed parameter systems of parabolic type using moving controls is considered, and conditions for existence of a solution are established.
Abstract: A nonlinear problem of moments, encountered in control of distributed parameter systems of parabolic type using moving controls will be considered. Using relaxed controls the problem will be written in a linear form. Conditions for existence of a solution will be established.