scholarly journals Discrete variable structure system with pseudo-sliding mode

1991 ◽  
Vol 32 (4) ◽  
pp. 365-376 ◽  
Author(s):  
R. B. Potts ◽  
X. Yu
Keyword(s):  
Numerical Solutions ◽  
Sliding Mode ◽  
Sufficient Conditions ◽  
Continuous System ◽  
Variable Structure ◽  
Sliding Modes ◽  
Discrete Variable ◽  
Variable Structure Systems ◽  
Variable Structure System ◽  
Necessary And Sufficient

AbstractVariable structure systems with sliding modes have been widely discussed and used in many different fields of applications. The precise behaviour at a switching surface is complicated because there the system is non-analytic. The damped simple harmonic oscillator with a nonlinear variable structure is discretised and analysed in detail, revealing the occurrence and structure of pseudo-sliding modes which give insight to the corresponding sliding modes for the continuous system. Necessary and sufficient conditions are obtained and the analysis illustrated with graphs from numerical solutions.

scholarly journals Computer-controlled variable-structure systems

1992 ◽  
Vol 34 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Xinghuo Yu ◽  
Renfrey B. Potts
Keyword(s):  
Computer Control ◽  
Sufficient Conditions ◽  
Variable Structure ◽  
Dimensional System ◽  
Sliding Modes ◽  
Variable Structure Systems ◽  
Computer Controlled ◽  
Two Dimensional System ◽  
Necessary And Sufficient ◽  
Theoretical Results

AbstractA theory is developed for the computer control of variable-structure systems, using periodic zero-order-hold sampling. A simple two-dimensional system is first analysed, and necessary and sufficient conditions for the occurrence of pseudo-sliding modes are discussed. The method is then applied to a discrete model of a cylindrical robot. The theoretical results are illustrated by computer simulations.

Design of Variable Structure Control with Bounded Inputs

2010 ◽  
Vol 29-32 ◽  
pp. 1175-1180
Author(s):  
Qing Kun Zhou ◽  
Sheng Jian Bai ◽  
Zhi Yong Zhang
Keyword(s):  
Closed Loop ◽  
Controller Design ◽  
Sliding Mode ◽  
Variable Structure ◽  
Closed Loop System ◽  
Variable Structure Systems ◽  
Structure Control ◽  
Variable Structure System ◽  
Lti System ◽  
The Stability

The design of variable structure system inputs which are constrained by saturation is studied. For a LTI system which satisfies some conditions, it is shown that appropriate bounded controllers guarantee the system’s global stability and maximize the sliding mode domain on the switching surfaces. Stability conditions of variable structure systems with constrained inputs are relaxed, and the stability of the closed-loop system is guaranteed by using passivity theory of linear passive systems. Moreover, nonlinear sliding surfaces are discussed for variable structure controller design, and a novel nonlinear switching surface is proposed. Finally, the proposed methods are applied to a 2nd order LTI system to show their usefulness.

scholarly journals NonlinearL2-Gain Analysis of Hybrid Systems in the Presence of Sliding Modes and Impacts

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
T. Osuna ◽  
O. E. Montano ◽  
Y. Orlov
Keyword(s):  
Sliding Mode ◽  
Numerical Study ◽  
Sufficient Conditions ◽  
Disturbance Attenuation ◽  
Sliding Modes ◽  
Time Dynamics ◽  
Attenuation Level ◽  
Disturbance Factor ◽  
Disturbance Attenuation Level ◽  
The Impact

TheL2-gain analysis is extended towards hybrid mechanical systems, operating under unilateral constraints and admitting both sliding modes and collision phenomena. Sufficient conditions for such a system to be internally asymptotically stable and to possessL2-gain less than ana priorigiven disturbance attenuation level are derived in terms of two independent inequalities which are imposed on continuous-time dynamics and on discrete disturbance factor that occurs at the collision time instants. The former inequality may be viewed as the Hamilton-Jacobi inequality for discontinuous vector fields, and it is separately specified beyond and along sliding modes, which occur in the system between collisions. Thus interpreted, the former inequality should impose the desired integral input-to-state stability (iISS) property on the Filippov dynamics between collisions whereas the latter inequality is invoked to ensure that the impact dynamics (when the state trajectory hits the unilateral constraint) are input-to-state stable (ISS). These inequalities, being coupled together, form the constructive procedure, effectiveness of which is supported by the numerical study made for an impacting double integrator, driven by a sliding mode controller. Desired disturbance attenuation level is shown to satisfactorily be achieved under external disturbances during the collision-free phase and in the presence of uncertainties in the transition phase.

scholarly journals Tracking Control of Variable Structure System Using Variable Boundary Layer

2001 ◽  
Vol 5 (6) ◽  
pp. 338-345
Author(s):  
Heejin Lee ◽  
Keyword(s):  
Boundary Layer ◽  
Tracking Control ◽  
Linear Time ◽  
Variable Structure ◽  
Second Order ◽  
Initial State ◽  
Variable Boundary ◽  
Variable Structure Systems ◽  
Variable Structure System ◽  
Arbitrary Initial State

In this paper, a new scheme is presented for the accurate tracking control of the second-order variable structure systems using the variable boundary layer. Up to now, variable structure controller(VSC) applying the variable boundary layer did not remove chattering from an arbitrary initial state of the system trajectory because VSC has used the fixed sliding surface. But, by using the linear time-varying sliding surfaces, the scheme has the robustness against chattering from all states. The suggested method can be applied to the second-order nonlinear systems with parameter uncertainty and extraneous disturbances, and have better tracking performance than the conventional method.To demonstrate the advantages of the proposed algorithm, it is applied to a two-link manipulator.

Sliding Mode Control of a Three Degrees of Freedom Anthropoid Robot by Driving the Controller Parameters to an Equivalent Regime

2000 ◽  
Vol 122 (4) ◽  
pp. 632-640 ◽  
Author(s):  
M. Onder Efe ◽  
Okyay Kaynak ◽  
Xinghuo Yu
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Tracking Error ◽  
Variable Structure ◽  
Mathematical Representation ◽  
Dynamic Complexity ◽  
Variable Structure Systems ◽  
Sliding Motion ◽  
Three Degrees Of Freedom

Noise rejection, handling the difficulties coming from the mathematical representation of the system under investigation and alleviation of structural or unstructural uncertainties constitute prime challenges that are frequently encountered in the practice of systems and control engineering. Designing a controller has primarily the aim of achieving the tracking precision as well as a degree of robustness against the difficulties stated. From this point of view, variable structure systems theory offer well formulated solutions to such ill-posed problems containing uncertainty and imprecision. In this paper, a simple controller structure is discussed. The architecture is known as Adaptive Linear Element (ADALINE) in the framework of neural computing. The parameters of the controller evolve dynamically in time such that a sliding motion is obtained. The inner sliding motion concerns the establishment of a sliding mode in controller parameters, which aims to minimize the error on the controller outputs. The outer sliding motion is designed for the plant. The algorithm discussed drives the error on the output of the controller toward zero learning error level, and the state tracking error vector of the plant is driven toward the origin of the phase space simultaneously. The paper gives the analysis of the equivalence between the two sliding motions and demonstrates the performance of the algorithm on a three degrees of freedom, anthropoid robotic manipulator. In order to clarify the performance of the scheme, together with the dynamic complexity of the plant, the adverse effects of observation noise and nonzero initial conditions are studied. [S0022-0434(00)01704-4]

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