Juan Diego Sanchez-Torres

High-Order Sliding Mode Block Control of Single-Phase Induction Motor

A new sliding mode (SM) observer-based controller for single-phase induction motor is designed. The proposed control scheme is formulated using block control feedback linearization technique and high-order SM algorithms with measurements of the rotor speed and stator currents. The stability of the complete closed-loop system, including the rotor flux second-order SM observer, is analyzed in the presence of model uncertainty, namely, rotor resistance variation and bounded time-varying load torque.

Predefined-time stability of dynamical systems with sliding modes

This paper introduces a class of fixed-time stable dynamical systems with settling time as a explicit parameter, namely the inverse the gain. Those systems are defined as predefined-timed stable dynamical systems. Continuous and discontinuous are cases are presented. A detailed Lyapunov characterization of this class of systems is also shown. Finally, the application to the design of a class of first order sliding mode controllers is exposed.

A discontinuous recurrent neural network with predefined time convergence for solution of linear programming

The aim of this paper is to introduce a new recurrent neural network to solve linear programming. The main characteristic of the proposed scheme is its design based on the predefined-time stability. The predefined-time stability is a stronger form of finite-time stability which allows the a priori definition of a convergence time that does not depend on the network initial state. The network structure is based on the Karush-Kuhn-Tucker (KKT) conditions and the KKT multipliers are proposed as sliding mode control inputs. This selection yields to an one-layer recurrent neural network in which the only parameter to be tuned is the desired convergence time. With this features, the network can be easily scaled from a small to a higher dimension problem. The simulation of a simple example shows the feasibility of the current approach.

ABS + active suspension control via sliding mode and linear geometric methods for disturbance attenuation

This paper deals with the control of an Anti-lock Brake System (ABS) assisted with an active suspension. The main objective is to track the slip rate of a car and ensure a shorter distance in the braking process. For the ABS subsystem an integral nested sliding mode controller based on the block control principle is designed. On the other hand, for the active suspension subsystem a sliding mode controller based on regular form and linear geometric techniques is proposed. Both closed-loop subsystems are robust in presence of matched and unmatched perturbations. To show the performance of the proposed control strategy, a simulation study is carried on, where results show good behavior of the ABS with active suspension under variations in the road.

Robust nested sliding mode integral control for anti-lock brake system

An integral nested Sliding Mode (SM) block control is proposed to control an Anti-lock Brake System (ABS) by employing integral SM and nested SM concepts. The control problem is to achieve reference tracking for the slip rate, in such a way that the friction between the tyre and the road surface is good enough to control the car. The closed-loop system is robust in the presence of matched and unmatched perturbations. To show the performance of the proposed control strategy, a simulation study is carried on, where results show good behaviour of the ABS under variations in the road friction.

A fixed-time second order sliding mode observer for a class of nonlinear systems

This paper presents a second order fixed time sliding mode observer based on an extension of the super-twisting algorithm. This observer can be applied to a class of nonlinear system with a block-wise representation. The block structure provides a straightforward form to the application of the proposed second order sliding mode algorithm, yielding to finite-time convergence with a settling time independent to the system initial conditions. Finally, as numerical simulation example, the case of a linear induction motor is studied, exposing the efficiency and feasibility of the proposal.

Recurrent neural networks with fixed time convergence for linear and quadratic programming

In this paper, a new class of recurrent neural networks which solve linear and quadratic programs are presented. Their design is considered as a sliding mode control problem, where the network structure is based on the Karush-Kuhn-Tucker (KKT) optimality conditions with the KKT multipliers considered as control inputs to be implemented with fixed time stabilizing terms, instead of common used activation functions. Thus, the main feature of the proposed network is its fixed convergence time to the solution. That means, there is time independent to the initial conditions in which the network converges to the optimization solution. Simulations show the feasibility of the current approach.

An equivalent control based sliding mode observer using high order uniform robust sliding operators

In this paper a sliding-mode observer based on the equivalent control method for discontinuous functions for a class of non-linear systems is proposed. The observer structure and its existence conditions are presented. Besides, a class of high order sliding operators with the properties of uniform (w.r.t. initial conditions) finite time convergence and with reduction of chattering effect are exposed. The use of these operators in the observer design allows the calculation of the equivalent control and the observer convergence uniformly in finite time. A simulation example is presented to illustrate the proposed method.

High order integral nested sliding mode control

This paper exposes a controller for the nonlinear systems in the block controllable form. This proposal guarantees exponential exact tracking in the presence of unknown matched and unmatched disturbances by means a combination of the block control method and integral terms designed with high-order sliding-modes algorithms. Both, matched and unmatched, disturbances are compensated by those integral continuous terms and the tracking is achieved with the design of a nominal control law.

Integral high order sliding mode control of single-phase induction motor

An observer-based controller for the single-phase induction motor is proposed in this paper. The scheme presented is formulated using block control feedback linearization technique and high order sliding mode algorithms with measurements of the rotor speed and stator currents. A second order sliding mode observer is included into the controller design in order to obtain estimates of the rotor flux. The stability of the complete closed-loop system is analyzed in the presence of model uncertainty, namely, rotor resistance variation and bounded time-varying load torque.