Showing papers on "Sliding mode control published in 1978"
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01 Jan 1978
TL;DR: An electric dynamically operated storage element comprises two energy stores and circuitry is provided for applying periodically repeating phase clock pulses simultaneously to the energy stores through the charging circuits.
Abstract: An electric dynamically operated storage element comprises two energy stores. Each store has a charging circuit including a rectifying element and a discharging circuit including a controlled respectively variable resistance connected in series with the rectifying element. Also, circuitry is provided for applying periodically repeating phase clock pulses simultaneously to the energy stores through the charging circuits.
1,802 citations
TL;DR: In this paper, a feedback controller is developed for a finite number of modes of the flexible system and the controllability and observability conditions necessary for successful operation are displayed, and the combined effect of control and observation spillover is shown to lead to potential instabilities in the closed-loop system.
Abstract: Feedback control is developed for the class of flexible systents described by the generalized wave equation with damping. The control force distribution is provided by a number of point force actuators and the system displacements and/or their velocities are measured at various points. A feedback controller is developed for a finite number of modes of the flexible system and the controllability and observability conditions necessary for successful operation are displayed. The control and observation spillover due to the residual (uncontrolled) modes is examined and the combined effect of control and observation spillover is shown to lead to potential instabilities in the closed-loop system. Some remedies for spillover, including a straightforward phase-locked loop prefilter, are suggested to remove the instability mechanism. The concepts of this paper are illustrated by some numerical studies on the feedback control of a simply-supported Euler-Bernoulli beam with a single actuator and sensor.
792 citations
01 Feb 1978
TL;DR: It is verified through hybrid simulation that trajectories which are close to ideal sliding modes exist when the controller is designed according to theory.
Abstract: A new control algorithm is developed for manipulators using the theory of variable structure systems. The control is designed so that a new type of state space trajectories called sliding mode exists. Due to delays, neglected small time constants, and other idealizations, ideal sliding modes as predicted by the theory do not exist. We have verified through hybrid simulation that trajectories which are close to ideal sliding modes exist when the controller is designed according to theory. To illustrate the design procedures, a two-joint manipulator is considered.
595 citations
TL;DR: A new design concept for adaptive model-following control systems capable of shaping the error transient responses is developed using the theory of variable structure systems and sliding mode and it is shown that the resulting model- Following control system exhibits adaptive properties inherent in adaptive model -following systems designed by existing methods.
Abstract: A new design concept for adaptive model-following control systems capable of shaping the error transient responses is developed using the theory of variable structure systems and sliding mode. It is shown that the resulting model-following control system exhibits adaptive properties inherent in adaptive model-following systems designed by existing methods. An aircraft control problem which has been approached using various model-following techniques is considered and a performance comparison with the present design is made.
182 citations
01 Jan 1978
TL;DR: In this paper, a new parameter adaptive control scheme is outlined which essentially allows one to arbitrarily position all of the poles of an unknown, linear, scalar system of known dynamical order, and it is shown that the overall control configuration, consisting of a system identifier and a complementary adaptive observer, is globally stable provided only that the control input is "sufficiently rich" in frequency content.
Abstract: A new parameter adaptive control scheme is outlined which essentially allows one to arbitrarily position all of the poles of an unknown, linear, scalar system of known dynamical order. The technique is based on identifying the parameters which characterize the dynamical behavior of the system in differential operator form and simultaneously implementing an adaptive observer which generates a feedback control signal which converges to the equivalent of an appropriate pole placing linear state variable control law. It is shown that the overall control configuration, consisting of a system identifier and a complementary adaptive observer, is globally stable provided only that the control input is "sufficiently rich" in frequency content. A study employing an unstable, nonminimum phase plant is presented to illustrate the technique.
66 citations
01 Jan 1978
TL;DR: In this paper, a general approach is developed for the nonlinear control of multivariable systems such that the transient responses exhibit the desired properties, and the closed loop systems are asymptotically stable.
Abstract: It is often desirable to have controllers which respond fast to large errors and which respond slowly to the small errors that are often due to sensor noise. Some nonlinear controllers having these properties are developed here by modifying optimal linear state feedback controllers so that they have state-dependent gains. A general approach is developed for the nonlinear control of multivariable systems such that the transient responses exhibit the desired properties, and the closed loop systems are asymptotically stable.
34 citations
TL;DR: In this article, the differential equations of slow motion in the systems with a large feedback gain were obtained using the equivalent control method developed for the analysis of sliding mode in systems with discontinuous controls.
Abstract: Differential equations of slow motion in the systems with a large feedback gain are obtained using the equivalent control method developed for the analysis of sliding mode in systems with discontinuous controls [1].
31 citations
TL;DR: In this article, the authors discuss generic stability of certain properties under the perturbation of control systems, and find that their results vary with dimension of the Euclidean space or manifold on which the control system is defined.
Abstract: Here we discuss generic stability of certain properties under the perturbation of control systems. The systems under consideration are nonlinear systems with scalar control appearing linearly. We find that our results vary with dimension of the Euclidean space or manifold on which the control system is defined.
11 citations
8 citations
TL;DR: In this paper, the authors show that for any control strategy σ and independent of preferred direction choices, there will be a controllable linear time-invariant system which is rendered unstable under σ, even if arbitrarily large inputs and nonlinear dependence of σ on its arguments is permitted.
Abstract: In recent years, a number of nonlinear power system stabilization problems have been approached using techniques termed "velocity-matching" or "optimal-aiming" strategies. At each instant of time, these strategies require that the velocity of the system be adjusted through instantaneous control action such that the state moves in some "preferred" direction subject to constraints imposed by an admissible input set, the choice of a preferred direction producing the different control strategies. In this paper, we show that for any such control strategy σ and independent of preferred direction choices, there will be a controllable linear time-invariant system which is rendered unstable under σ, even if arbitrarily large inputs and nonlinear dependence of σ on its arguments is permitted.
5 citations
TL;DR: In this article, a cellular decomposition of the controllable set for small response times for a new generic class of systems called "minimally controLLable systems" is presented.
Abstract: This paper introduces a new technique for the analysis of time-optimal systems having multidimensional inputs. The method provides a cellular decomposition of the controllable set for small response times for a new generic class of systems called "minimally controllable systems." The decomposition permits a complete study of the time-optimal flow near the origin and forms the basis for the synthesis of closed-loop optimal control. The method, while generally applicable, is restricted here to the simplest, nontrivial case of third-order systems with two-dimensional controls.
01 Jan 1978
TL;DR: The time-optimal control of a class of nonlinear singularly perturbed systems possesses the two time-scale property that the optimal control is made of a control in a slow-time scale followed by a Control in a fast time scale.
Abstract: The time-optimal control of a class of nonlinear singularly perturbed systems possesses the two time-scale property that the optimal control is made of a control in a slow-time scale followed by a control in a fast time-scale. Based on this property a near time-optimal control is defined. Two examples illustrating the computation of the near-optimal control and a simple iterative technique are presented.
01 Jan 1978
TL;DR: In this article, a new parameter adaptive control scheme is outlined which essentially allows one to arbitrarily position all of the poles of an unknown, linear, scalar system of known dynamical order, and it is shown that the overall control configuration consisting of a system identifier and a complementary adaptive observer is globally stable provided only that the control input is "sufficiently rich" in frequency content.
Abstract: A new parameter adaptive control scheme is outlined which essentially allows one to arbitrarily position all of the poles of an unknown, linear, scalar system of known dynamical order. The technique is based on identifying the parameters which characterize the dynamical behavior of the system in differential operator form and simultaneously implementing an adaptive observer which generates a feedback control signal which converges to the equivalent of an appropriate pole placing linear state variable control law. It is shown that the overall control configuration, consisting of a system identifier and a complementary adaptive observer, is globally stable provided only that the control input is "sufficiently rich" in frequency content.