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]

Control of Fractional-Order Systems Using Chatter-Free Sliding Mode Approach

2014 ◽  
Vol 9 (3) ◽  
Author(s):  
Mohammad Pourmahmood Aghababa
Keyword(s):  
Fractional Derivative ◽  
Sliding Mode ◽  
Variable Structure ◽  
Stability And Convergence ◽  
Control Input ◽  
Fractional Systems ◽  
Sliding Motion ◽  
Efficient Performance ◽  
Sliding Manifold ◽  
Chattering Free

The problem of stabilization of nonlinear fractional systems in spite of system uncertainties is investigated in this paper. First, a proper fractional derivative type sliding manifold with desired stability and convergence properties is designed. Then, the fractional stability theory is adopted to derive a robust sliding control law to force the system trajectories to attain the proposed sliding manifold and remain on it evermore. The existence of the sliding motion is mathematically proven. Furthermore, the sign function in the control input, which is responsible to the being of harmful chattering, is transferred into the fractional derivative of the control input. Therefore, the resulted control input becomes smooth and free of the chattering. Some numerical simulations are presented to illustrate the efficient performance of the proposed chattering-free fractional variable structure controller.

A novel DTC scheme for a sensorless five-phase IM drive under open-phase fault

2019 ◽  
Vol 38 (2) ◽  
pp. 829-844
Author(s):  
Hamdi Echeikh ◽  
Hichem Kesraoui ◽  
Ramzi Trabelsi ◽  
Atif Iqbal ◽  
Mohamed Faouzi Mimouni
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Direct Torque Control ◽  
Low Frequency ◽  
Variable Structure ◽  
Torque Control ◽  
Theoretical Development ◽  
Content Type ◽  
Open Phase ◽  
Stator Flux

Purpose This paper aims to deal with direct torque controller when the five-phase induction motor drive in faulty operation. Precisely, open-phase fault condition is contemplated. Also, the DTC is combined with a speed-adaptive variable-structure observer based on sliding mode observer. Design methodology/approach Two novel features are presented. First, the concept of the virtual voltage vector is presented, which eliminates low-frequency harmonic currents and simplifies analysis. Second, speed information is introduced into the selection of the inverter states. Findings Direct torque control (DTC) is largely used in traditional three-phase drives as a backup to rotor-stator flux-oriented methods. The classic DTC strategy was primarily designed on the base of hysteresis controllers to control two independent variables (speed, torque and flux). Due to the additional degrees of freedom offered by multiphase machine, extensive works have been extended on the ensemble five-phase drives in healthy operation. In addition, the ability to continue the operation in faulty conditions is considering one of the main advantages of multiphase machines. One can find in the literature different approaches treating this subject. The applicability of DTC after the appearing of a fault has not been enclosed in the literature. Originality/value Theoretical development is presented in details followed by simulation results using Matlab/Simulink to analyze the performance of the drive, comparing with the behavior during healthy situation.

A class of C∞-integrable Hamiltonian systems

1989 ◽  
Vol 113 (3-4) ◽  
pp. 293-314 ◽  
Author(s):  
W. M. Oliva ◽  
M. S. A. C. Castilla
Keyword(s):  
Hamiltonian Systems ◽  
Degrees Of Freedom ◽  
Initial Conditions ◽  
First Integrals ◽  
Integrable Hamiltonian Systems ◽  
Integral Of Motion ◽  
Toda System ◽  
Nonnegative Coefficients ◽  
Special Case ◽  
Three Degrees Of Freedom

SynopsisWe discuss the C∞ complete integrability of Hamiltonian systems of type q = —grad V(q) = F(q), in which the closure of the cone generated (with nonnegative coefficients) by the vectors F(q), q ϵ ℝn, does not contain a line. The components of the asymptotic velocities are first integrals and the main aim is to prove their smoothness as functions of the initial conditions. The Toda-like system with potential V(q)=ΣNi=1 exp(fi∣ q) is a special case of the considered systems ifthe cone C(f1,…,fN)={ΣNi=1cifi,ci≧0} does notcontain a line. In any number of degrees of freedom, if C(f1,…,fN) has amplitude not too large (ang (fi, fj ≦π/2i,j=1,2,…, N), the first integrals are C∞ functions. In two degrees of freedom, without restriction on the amplitude of the cone, C∞-integrability is proved even in a case in which it is known that there is no other meromorphic integral of motion independent of energy. In three degrees of freedom the C∞-integrability of a deformation of the classic nonperiodic Toda system is proved. Some other examples are also discussed.

scholarly journals Variable Structure Controller for Surface Ship Steering

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Ringo Rimbe ◽  
Raidandi Danwe ◽  
Babagana M Mustapha
Keyword(s):  
Sliding Mode ◽  
Linear Time ◽  
Variable Structure ◽  
Time Varying ◽  
Variable Structure Systems ◽  
Ship Model ◽  
Linear Time Invariant ◽  
Surface Ship ◽  
Ship Steering ◽  
Time Varying Environment

A Lyapunov approach to constructing switching surfaces for variable structure systems is investigated in this paper. The method guarantees sliding mode for any initial condition of the state vector and asymptotic stability is always achieved during sliding motion. An application for  the design of  a variable structure ship steering controller is carried out and  simulation results are presented. The designed controller exhibits robustness as applied to a linear time-invariant ship model and a time varying non-linear  ship model operating in  an uncertain and  time-varying environment.

Sliding Mode Control Techniques in E-Learning Systems

2016 ◽  
pp. 78-95
Author(s):  
I. Boiko ◽  
H. Hussein ◽  
A. Al Durra
Keyword(s):  
Sliding Mode Control ◽  
Dynamic Models ◽  
Sliding Mode ◽  
Variable Structure ◽  
Optimal Level ◽  
Learning Systems ◽  
Variable Structure Systems ◽  
Control Techniques ◽  
Mode Control ◽  
E Learning

Perspectives of using sliding mode control in e-learning are discussed. The concepts of variable structure systems and sliding mode control are given. Analysis of convergence based on the second Lyapunov's method is presented. The analysis presented is based on the dynamic models of learning available in the literature. The suitability of the use of sliding mode to adaptation of level of challenge of the tasks in e-learning is demonstrated. It is shown that with frequent enough evaluation of tasks, optimal level of task challenge can be ensured.

A Novel Fuzzy Sliding Mode Control Scheme for Nonlinear Systems with Bounded Inputs

2002 ◽  
Vol 8 (7) ◽  
pp. 945-965 ◽  
Author(s):  
Juhng-Perng Su ◽  
Chi-Ying Liang
Keyword(s):  
Sliding Mode Control ◽  
Fuzzy Controller ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Variable Structure ◽  
Single Frequency ◽  
Bench Mark ◽  
Mode Control ◽  
Variable Structure System ◽  
Control Scheme

In this paper, we investigated the design of robust controllers for a class of nonlinear uncertain systems with bounded inputs, which have not yet been thoroughly discussed. Based on the variable structure system theory, we developed a novel stable sliding mode control scheme for this class of systems. A key feature of this control scheme is the introduction of a new generalized error as a complement to the conventional generalized error to form a meaningful error measure so that a new sliding mode controller incorporated with a two-input one-output fuzzy controller can be constructed to improve the reaching behavior of the system during the reaching phase as well as the tracking precision while in the boundary layer. The nonlinear bench mark problem, TORA, was used as an example to demonstrate the effectiveness of the design. Simulation results showed that, as compared with various available controllers in literature, much better responses to any initial conditions and to single-frequency sinusoidal disturbances can be obtained.

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.

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