scholarly journals Optimization of Sliding Mode Control to Save Energy in a SCARA Robot

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3160
Author(s):  
Luis Arturo Soriano ◽  
José de Jesús Rubio ◽  
Eduardo Orozco ◽  
Daniel Andres Cordova ◽  
Genaro Ochoa ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Bat Algorithm ◽  
Position Tracking ◽  
Sliding Mode Controller ◽  
Tracking Problem ◽  
External Disturbances ◽  
Scara Robot ◽  
Mode Control ◽  
Save Energy

Sliding mode control is a robust technique that is used to overcome difficulties such as parameter variations, unmodeled dynamics, external disturbances, and payload changes in the position-tracking problem regarding robots. However, the selection of the gains in the controller could produce bigger forces than are required to move the robots, which requires spending a large amount of energy. In the literature, several approaches were used to manage these features, but some proposals are complex and require tuning the gains. In this work, a sliding mode controller was designed and optimized in order to save energy in the position-tracking problem of a two-degree-of-freedom SCARA robot. The sliding mode controller gains were optimized usinga Bat algorithm to save energy by minimizing the forces. Finally, two controllers were designed and implemented in the simulation, and as a result, adequate controller gains were found that saved energy by minimizing the forces.

Sliding Mode Control of an Actuated Knee Joint Orthosis

2021 ◽  
Vol 15 ◽  
Author(s):  
Imen Saidi ◽  
Asma Hammami
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Sliding Mode ◽  
Position Tracking ◽  
Sliding Mode Controller ◽  
Mechanical Device ◽  
Tracking Errors ◽  
Mode Control ◽  
Speed Tracking ◽  
Human Morphology

Introduction: In this paper, a robust sliding mode controller is developed to control an orthosis used for rehabilitation of lower limb. Materials and Methods: The orthosis is defined as a mechanical device intended to physically assist a human subject for the realization of his movements. It should be adapted to the human morphology, interacting in harmony with its movements, and providing the necessary efforts along the limbs to which it is attached. Results: The application of the sliding mode control to the Shank-orthosis system shows satisfactory dynamic response and tracking performances. Conclusion: In fact, position tracking and speed tracking errors are very small. The sliding mode controller effectively absorbs disturbance and parametric variations, hence the efficiency and robustness of our applied control.

scholarly journals Dynamic modeling and adaptive fuzzy terminal sliding mode controller with nonlinear observer of a 2-(PUU)2R hybrid mechanism

2019 ◽  
Vol 16 (2) ◽  
pp. 172988141982956 ◽  
Author(s):  
Xing Zhang ◽  
Dejun Mu ◽  
Hongrui Wang
Keyword(s):  
Sliding Mode Control ◽  
Dynamic Modeling ◽  
Sliding Mode ◽  
Nonlinear Observer ◽  
Sliding Mode Controller ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Adaptive Fuzzy ◽  
Mode Control ◽  
Hybrid Mechanism

This article proposes a new spatial 2-(PUU)2R hybrid mechanism that can perform the three degrees of freedom translation and one degree of freedom rotation and presents an analysis of the dynamics of the mechanism. An adaptive fuzzy terminal sliding mode controller with nonlinear observer for the hybrid mechanism is proposed to achieve a precise trajectory tracking, which could be utilized in solving the problems of the hybrid mechanism caused by model uncertainties, varying payloads, and external disturbances. Firstly, through the interrelation between the constraints, the 6 × 6 Jacobian matrix and 6 × 6 × 6 Hessian matrix for the mechanism are derived. Furthermore, dynamic modeling is established based on the virtual work principle, through which the characteristics of dynamic modeling can be proved. To achieve high-precision position tracking, a nonlinear observer was introduced to feed into the terminal sliding mode control which had improved the mechanism’s ability to resist the external disturbances. In addition, the chattering caused by the terminal sliding mode control was eliminated by approximating the switching gain with the usage of adaptive fuzzy logic in a finite time. Finally, a series of numerical simulations are carried out to prove the validity of the proposed approach, and the results verify better robustness and higher precision for the trajectory tracking than proportional–integral–derivative and sliding mode control.

scholarly journals New Time-Varying Sliding Surface for Switching Type Quasi-Sliding Mode Control

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3811
Author(s):  
Katarzyna Adamiak ◽  
Andrzej Bartoszewicz
Keyword(s):  
Sliding Mode Control ◽  
Continuous Time ◽  
Sliding Mode ◽  
Representative Point ◽  
Time Varying ◽  
Sliding Surface ◽  
External Disturbances ◽  
Mode Control ◽  
Switching Type ◽  
Time Systems

This study considers the problem of energetical efficiency in switching type sliding mode control of discrete-time systems. The aim of this work is to reduce the quasi-sliding mode band-width and, as follows, the necessary control input, through an application of a new type of time-varying sliding hyperplane in quasi-sliding mode control of sampled time systems. Although time-varying sliding hyperplanes are well known to provide insensitivity to matched external disturbances and uncertainties of the model in the whole range of motion for continuous-time systems, their application in the discrete-time case has never been studied in detail. Therefore, this paper proposes a sliding surface, which crosses the system’s representative point at the initial step and then shifts in the state space according to the pre-generated demand profile of the sliding variable. Next, a controller for a real perturbed plant is designed so that it drives the system’s representative point to its reference position on the sliding plane in each step. Therefore, the impact of external disturbances on the system’s trajectory is minimized, which leads to a reduction of the necessary control effort. Moreover, thanks to a new reaching law applied in the reference profile generator, the sliding surface shift in each step is strictly limited and a switching type of motion occurs. Finally, under the assumption of boundedness and smoothness of continuous-time disturbance, a compensation scheme is added. It is proved that this control strategy reduces the quasi-sliding mode band-width from O(T) to O(T3) order from the very beginning of the regulation process. Moreover, it is shown that the maximum state variable errors become of O(T3) order as well. These achievements directly reduce the energy consumption in the closed-loop system, which is nowadays one of the crucial factors in control engineering.

Study on Sliding Mode Control in Bidirectional DC/DC Converter Based on State Space Averaging Method

2014 ◽  
Vol 678 ◽  
pp. 399-405
Author(s):  
Yan Mei
Keyword(s):  
Sliding Mode Control ◽  
State Space ◽  
Averaging Method ◽  
Sliding Mode ◽  
Good Stability ◽  
Sliding Mode Controller ◽  
Battery Charging ◽  
Mode Control ◽  
Logic Diagram

Bidirectional DC/DC converter is used for the battery charging and discharging. The sliding mode controller based on state space averaging algorithm is used for controlling bidirectional DC/DC converter. Two kinds of working modes, buck mode and boost mode, have been analyzed and three kinds of working states which are consisted by two working modes have been deeply discussed, and the automatic switch logic diagram when battery charging and discharging through the bidirectional DC/DC converter has been presented. Situation of system based on S1, S2 conducting alternately has been studied, and the simulations were also presented. According to the results, the characteristics of good stability and transient can be confirmed.

Research on Adaptive Backstepping Global Sliding Control for CPS

2013 ◽  
Vol 846-847 ◽  
pp. 134-138
Author(s):  
Jue Wang ◽  
Fei Li ◽  
Ye Huang ◽  
Jian Hao Wang ◽  
Hong Lin Zhang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Flight Simulator ◽  
Position Tracking ◽  
Adaptive Backstepping ◽  
Parameter Uncertainties ◽  
Servo Systems ◽  
Mode Control ◽  
Global Sliding Mode Control ◽  
Compensation Methods

The paper studies the problem of tracking control for flight simulator servo systems, one typical CPS, with parameter uncertainties and nonlinear friction compensation. Methods of adaptive global sliding mode control and backstepping control are respectively proposed to realize the control of virtual rotational speed and position tracking. Adaptive backstepping global sliding mode control strategy for flight simulator servo systems is proposed and its stability is analyzed. Simulation results show the effectiveness of the proposed method, which could achieve the precision position tracking performance and eliminate the chattering.

scholarly journals Design of Composite Disturbance Observer and Continuous Terminal Sliding Mode Control for Piezoelectric Nanopositioning Stage

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2242
Author(s):  
Pengyu Qiao ◽  
Jun Yang ◽  
Chen Dai ◽  
Xi Xiao
Keyword(s):  
Sliding Mode Control ◽  
Control Strategy ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Accurate Estimation ◽  
Terminal Sliding Mode Control ◽  
External Disturbances ◽  
Terminal Sliding Mode ◽  
Composite Control ◽  
Mode Control

The nonlinearities of piezoelectric actuators and external disturbances of the piezoelectric nanopositioning stage impose great, undesirable influences on the positioning accuracy of nanopositioning stage systems. This paper considers nonlinearities and external disturbances as a lumped disturbance and designs a composite control strategy for the piezoelectric nanopositioning stage to realize ultra-high precision motion control. The proposed strategy contains a composite disturbance observer and a continuous terminal sliding mode controller. The composite disturbance observer can estimate both periodic and aperiodic disturbances so that the composite control strategy can deal with the disturbances with high accuracy. Meanwhile, the continuous terminal sliding mode control is employed to eliminate the chattering phenomenon and speed up the convergence rate. The simulation and experiment results show that the composite control strategy achieves accurate estimation of different forms of disturbances and excellent tracking performance.

scholarly journals Adaptive Moving Sliding Mode Control for SISO Systems: Application to an Electropneumatic System

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Assil Ayadi ◽  
Soufien Hajji ◽  
Mohamed Smaoui ◽  
Abdessattar Chaari
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Sliding Surface ◽  
External Disturbances ◽  
Single Input Single Output ◽  
Mode Control ◽  
Single Output ◽  
Single Input ◽  
Electropneumatic System ◽  
Siso Systems

This paper aims to propose and develop an adaptive moving sliding mode controller (AMSMC) that can be applied for nonlinear single-input single-output (SISO) systems with external disturbances. The main contribution of this framework consists to overcome the chattering phenomenon problem. The discontinuous term of the classic sliding mode control is replaced by an adaptive term. Moreover, a moving sliding surface is proposed to have better tracking and to guarantee robustness to the external disturbances. The parameters of the sliding surface and the adaptive law are deduced based on Lyapunov stability analysis. An experimental application of electropneumatic system is treated to validate the theoretical results.

scholarly journals Sliding Mode Control of Uncertain Neutral Stochastic Systems with Multiple Delays

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Dilan Chen ◽  
Weidong Zhang
Keyword(s):  
Sliding Mode Control ◽  
Stochastic Systems ◽  
Sliding Mode ◽  
Linear Matrix ◽  
Multiple Delays ◽  
Sliding Mode Controller ◽  
Matrix Inequalities ◽  
Neutral Systems ◽  
Mode Control ◽  
Neutral Stochastic Systems

This paper is concerned with the sliding mode control for uncertain stochastic neutral systems with multiple delays. A switching surface is adopted first. Then, by means of linear matrix inequalities (LMIs), a sufficient condition is derived to ensure the global stochastic stability of the stochastic system in the sliding mode for all admissible uncertainties. The synthesized sliding mode controller guarantees the existence of the sliding mode.

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