scholarly journals A Simple Soft Computing Structure for Modeling and Control

Machines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 168
Author(s):  
Hemza Redjimi ◽  
József Kázmér Tar
Keyword(s):  
Dynamic Models ◽  
Sliding Mode ◽  
Variable Structure ◽  
Adaptive Controller ◽  
Activation Function ◽  
Approximate Model ◽  
Single Step ◽  
Van Der Pol Oscillator ◽  
Output State ◽  
Incremental Model

Using the interpolation/extrapolation skills of the core function of an iterative adaptive controller, a structurally simple single essential layer neural network-based topological structure is suggested with fast and explicit single-step teaching and data-retrieving abilities. Its operation does not assume massive parallelism, therefore it easily can be simulated by simple sequential program codes not needing sophisticated data synchronization mechanisms. It seems to be advantageous in approximate model-based common, robust, or adaptive controllers that can compensate for the effects of minor modeling imprecisions. In this structure a neuron can be in either a firing or a passive (i.e., producing zero output) state. In firing state its activation function realizes an abstract rotation that maps the desired kinematic data into the space of the necessary control forces. The activation function allows the use of a simple and fast incremental model modification for slowly varying dynamic models. Its operation is exemplified by numerical simulations for a van der Pol oscillator in free motion, and within a Computed Torque type control. To reveal the possibility for efficient model correction, a robust Variable Structure/Sliding Mode Controller is applied, too. The novel structure can be obtained by approximate experimental observations as e.g., the fuzzy models.

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.

Comparison of Fractional Robust- and Fixed Point Transformations- Based Adaptive Compensation of Dynamic Friction

2007 ◽  
Vol 11 (9) ◽  
pp. 1062-1071 ◽  
Author(s):  
József K. Tar ◽  
◽  
Imre J. Rudas ◽  
Béla Pátkai ◽  
Keyword(s):  
Fixed Point ◽  
Sliding Mode ◽  
Time Derivative ◽  
Variable Structure ◽  
Adaptive Controller ◽  
Dynamic Friction ◽  
Adaptive Controllers ◽  
Error Metrics ◽  
Tilting Angle ◽  
Sliding Mode Variable Structure

The features of fractional order robust and fixed-point transformation based adaptive controllers of a “Ball-Beam System” are compared to each other. The speciality of this task is that the position of the ball along the beam is indirectly controlled via directly controlling the other axis, the tilting angle of the beam. It is assumed that this tilting axle suffers from considerable dynamic friction mathematically approximated by the LuGre model. By neglecting the internal physics of the tilting drive this system can be modeled as a 4thorder one because only the 4thtime-derivative of the ball’s position can directly be influenced by the tilting torque. The system also has saturation since the available acceleration of the ball is limited by the gravitation. It is shown that little reduction of the order of the differential equation controlling the decay of the error metrics in a Sliding Mode / Variable Structure controller considerably improves the robust controller. However, really precise solution can be obtained by the adaptive controller. These statements are illustrated and substantiated via simulation.

scholarly journals Differential Steering Control of Four-Wheel Independent-Drive Electric Vehicles

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2892 ◽  
Author(s):  
Jie Tian ◽  
Jun Tong ◽  
Shi Luo
Keyword(s):  
Electric Vehicles ◽  
Dynamic Models ◽  
Reference Model ◽  
Sliding Mode ◽  
Variable Structure ◽  
Front Wheel ◽  
Steering Control ◽  
Sideslip Angle ◽  
Differential Steering ◽  
Skid Steering

This paper investigates the skid steering of four-wheel independent-drive (4WID) electric vehicles (EV) and a differential steering of a 4WID EV with a steer-by-wire (SBW) system in case of steering failure. The dynamic models of skid steering vehicle (SSV) and differential steering vehicle (DSV) are established and the traditional front-wheel steering vehicle with neutral steering characteristics is selected as the reference model. On this basis, sideslip angle observer and two different sliding mode variable structure controllers for SSV and DSV are designed respectively. Co-simulation results of CarSim and Simulink show that the designed controller for DSV not only controls the yaw rate and sideslip angle of DSV to track those of the reference model exactly, but also ensures the robustness of the controlled system compared with the designed controller for SSV. And the differential driving torque needed to realize the differential steering is much smaller than that for skid steering, which indicates the possibility of the differential steering in case of steering failure.

scholarly journals Synchronous Generator Rectification System Based on Double Closed-Loop Control of Backstepping and Sliding Mode Variable Structure

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1832
Author(s):  
Jinfeng Liu ◽  
Xin Qu ◽  
Herbert Ho-Ching Iu
Keyword(s):  
Closed Loop ◽  
Control Structure ◽  
Low Voltage ◽  
Sliding Mode ◽  
Variable Structure ◽  
Synchronous Generator ◽  
Closed Loop Control ◽  
High Current ◽  
Loop Control ◽  
Sliding Mode Variable Structure

Low-voltage and high-current direct current (DC) power supplies are essential for aerospace and shipping. However, its robustness and dynamic response need to be optimized further on some special occasions. In this paper, a novel rectification system platform is built with the low-voltage and high-current permanent magnet synchronous generator (PMSG), in which the DC voltage double closed-loop control system is constructed with the backstepping control method and the sliding mode variable structure (SMVS). In the active component control structure of this system, reasonable virtual control variables are set to obtain the overall structural control variable which satisfied the stability requirements of Lyapunov stability theory. Thus, the fast-tracking and the global adjustment of the system are realized and the robustness is improved. Since the reactive component control structure is simple and no subsystem has to be constructed, the SMVS is used to stabilize the system power factor. By building a simulation model and experimental platform of the 5 V/300 A rectification module based on the PMSG, it is verified that the power factor of the system can reach about 98.5%. When the load mutation occurs, the DC output achieves stability again within 0.02 s, and the system fluctuation rate does not exceed 2%.

Methods of Discontinuous Control for the Autonomous Underwater Vehicles

2013 ◽  
Vol 278-280 ◽  
pp. 1473-1476
Author(s):  
Alexander Lebedev
Keyword(s):  
Reference Model ◽  
Sliding Mode ◽  
Autonomous Underwater Vehicles ◽  
Variable Structure ◽  
Underwater Vehicles ◽  
Adjustment Process ◽  
Centralized Control ◽  
Reciprocal Effect ◽  
Discontinuous Control ◽  
Adjustment System

New methods of the synthesis of multi-dimensional robust and adaptive control systems for the centralized control of the spatial motion of autonomous underwater vehicles (AUV) is developed in this paper, such as variable structure system (VSS) and self-adjustment system with reference model. The conditions of the sliding mode existence and the self-adjustment process stability with the presence of essential dynamic reciprocal effect between all control channels are obtained and strictly proved. The application of synthesized discontinuous control provides the high control quality at any variations of the object parameters within the given ranges.

CONTROLLING THE UNCERTAIN MULTI-SCROLL CRITICAL CHAOTIC SYSTEM WITH INPUT NONLINEAR USING SLIDING MODE CONTROL

2009 ◽  
Vol 23 (16) ◽  
pp. 2021-2034 ◽  
Author(s):  
XINGYUAN WANG ◽  
DA LIN ◽  
ZHANJIE WANG
Keyword(s):  
Chaotic System ◽  
Sliding Mode ◽  
Equilibrium Points ◽  
Dead Zone ◽  
Variable Structure ◽  
Sliding Mode Controller ◽  
Global Stabilization ◽  
Structure Control ◽  
Control Scheme ◽  
Simulation Results

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.

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