Sliding Mode State Observer Research Articles

Synthesis of a Control System of the Amphibian Aircraft Tangage under Wave Disturbances

AbstractThe paper deals with the tracking problem for multi-input multi-output systems under unknown smooth external disturbances within the framework of the block approach. The paper introduces the notion of the joint block-canonical form of controllability and observability of linear systems with respect to the output. Based on this form, decomposition algorithms of the synthesis of an invariant tracking system have been developed. The main feature is using sliding mode state observers for dataware of basic laws of the combined control. These observers are built as a replica of the joint block form with closed local feedbacks, what enables one to obtain current estimates of components of the control laws directly. Such an approach considerably simplifies the regulator structure, since it does not require direct and inverse real-time substitution of variables, as well as it does not require deriving dynamic models of reference and disturbing actions. Basing on the derived theoretical results, the decomposition synthesis of the feedback in the problem of control of the tangage of an amphibian aircraft under approaching landing under wave disturbances is implemented.

Robust control for a class of time-delay uncertain nonlinear systems based on sliding mode observer

In this paper, a robust control scheme is proposed for a class of time-delay uncertain nonlinear systems with unknown input using the sliding mode observer. The sliding mode state observer is given with radial basis function neural networks, and then the robust control scheme is presented based on the designed sliding mode observer. The developed observer-based control scheme consists of two parts. One term is a linear controller and the other term is a neural network controller. Using the Lyapunov method, a criterion for bounded stability of the closed-loop system is developed in terms of linear matrix inequalities. Finally, a simulation example is used to illustrate the effectiveness of the proposed robust control scheme.

Output Variables Control in Mechanical Systems

Manipulator endpoint location autonomous control procedures are suggested. A method of uplimited control hierarchy has been designed, which allows to provide a desired tracking precision under conditions of uncertainty of the control object operator and the effect of external unmeasured disturbances. Sliding mode state observers synthesis procedures have been designed, which allow, in a theoretically limited time interval, to obtain information on immeasurable variables of the state vector and available uncertainty. The results of the designed algorithms modeling are presented.

Direct Method of Manipulator Endpoint Control Synthesis

Manipulator endpoint location autonomous control procedures are suggested. A method of uplimited control hierarchy has been designed, which allows to provide a desired tracking precision under conditions of uncertainty of the control object operator and the effect of external unmeasured disturbances. Sliding mode state observers synthesis procedures have been designed, which allow, in a theoretically limited time interval, to obtain information on immeasurable variables of the state vector and available uncertainty. The results of the designed algorithms modeling are presented.

Sliding mode state observers for discrete-time linear systems

In discrete-time systems, instead of having a hyperplane as in the continuous case, there is a countable set of points comprising a so-called lattice; and the surface on which these sliding points lie is named the latticewise hyperplane. In this paper an asymptotically stable observer for discrete-time systems is designed by using the properties of the sliding mode such that the stability of the error system in the sliding mode is maintained. Various techniques for finding the feedforward injection map are proposed. The stability of the reconstruction error system with a bounded perturbation signal is studied.

Sliding mode observer-based control for a class of bioreactors

A robust control algorithm which uses partial state feedback is designed for a class of biochemical processes in the presence of modeling uncertainties. To design the controller, the model uncertainty and the nonmeasurable state are combined into a new state variable. A sliding mode state observer is used to obtain on-line estimates of this new state. A practical stabilizer is obtained by combining the observer with an input–output linearizing controller. The practical convergence of the observer and the controller are proved. The performance of the sliding mode observer and the closed-loop behavior is illustrated through numerical simulations.