scholarly journals Efficient Control of a Non-Linear System Using a Modified Sliding Mode Control

2019 ◽  
Vol 9 (7) ◽  
pp. 1284 ◽  
Author(s):  
Saad Abbasi ◽  
Karam Kallu ◽  
Min Lee
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Sliding Surface ◽  
Parameter Uncertainties ◽  
Pass Filter ◽  
Mode Control ◽  
Efficient Control ◽  
Non Linear ◽  
Non Linear System

Trajectory tracking is an essential requirement in robot manipulator movement and localization applications. It is a current research topic of interest, and several researchers have proposed different schemes to achieve the task accurately. This research proposes efficient control of a hydraulic non-linear robot manipulator using a modified sliding mode control, named proportional derivative sliding mode control with sliding perturbation observer (PDSMCSPO), to overcome parameter uncertainties and non-linearity. The proposed new control strategy achieves higher accuracy and better time convergence than the previous one. A positive derivative gain, which has a value less than one, is multiplied with the velocity error term of the sliding surface. The proposed control (PDSMCSPO) also achieves robustness. Results show that by introducing the derivative gain, the chattering from the system has been reduced more than classical sliding mode control (SMC). The reason is that during reaching phase this small gain multiplies with the perturbation and minimizes the effect of perturbation on the system. A smaller value of switching gain K is required as compared to SMC, and the transfer function between sliding surface and perturbation in proportional derivative sliding mode control (PDSMC)has low pass filter characteristics. The proposed PDSMCSPO has a faster response than previous sliding mode control with sliding perturbation observer (SMCSPO), and the output and sliding surface convergence to the desired value is much quicker than conventional logic. Some other characteristics such as error in the output are small because of more attenuation of the perturbation signal. Simulation and experimental results are presented for a link between the hydraulic robot manipulator and the mass damper system.

scholarly journals A Multi-Slope Sliding-Mode Control Approach for Single-Phase Inverters under Different Loads

2016 ◽  
Author(s):  
Ghazanfar Shahgholian ◽  
Babk Khajeh Shalaly
Keyword(s):  
Sliding Mode Control ◽  
Single Phase ◽  
Sliding Mode ◽  
Main Idea ◽  
Sliding Surface ◽  
Tracking Accuracy ◽  
Control Approach ◽  
Mode Control ◽  
Non Linear ◽  
Slope Function

In this paper, a new approach to the sliding-mode control of single-phase inverters under linear and non-linear loads is introduced. The main idea behind this approach is to utilize a non-linear, flexible and multi-slope function in controller structure. This non-linear function makes the controller possible to control the inverter by a non-linear multi-slope sliding surface. In general, this sliding surface has two parts with different slopes in each part and the flexibility of the sliding surface makes the multi-slope sliding-mode controller (MSSMC) possible to reduce the total harmonic distortion, to improve the tracking accuracy, and to prevent overshoots leading to undesirable transient-states in output voltage which are occurred when the load current sharply rises. In order to improve the tracking accuracy and to reduce the steady-state error, an integral term of the multi-slope function is also added to the sliding surface. The improved performance of the proposed controller is confirmed by simulations and finally, the results of the proposed approach are compared with a conventional SMC and a SRFPI controller.

scholarly journals Sliding Mode Control Based on Observer for a Class of State-Delayed Switched Systems with Uncertain Perturbation

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Zhaolan He ◽  
Xue Wang ◽  
Zongwei Gao ◽  
Jingjie Bai
Keyword(s):  
Sliding Mode Control ◽  
Switched Systems ◽  
Sliding Mode ◽  
Estimation Error ◽  
Matching Condition ◽  
State Observer ◽  
Sliding Surface ◽  
State Variables ◽  
Parameter Uncertainties ◽  
Mode Control

This paper is concerned with a state observer-based sliding mode control design methodology for a class of continuous-time state-delayed switched systems with unmeasurable states and nonlinear uncertainties. The advantages of the proposed scheme mainly lie in which it eliminates the need for state variables to be full accessible and parameter uncertainties to be satisfied with the matching condition. Firstly, a state observer is constructed, and a sliding surface is designed. By matrix transformation techniques, combined with Lyapunov function and sliding surface function, a sufficient condition is given to ensure asymptotic stability of the overall closed-loop systems composed of the observer dynamics and the estimation error dynamics. Then, reachability of sliding surface is investigated. At last, an illustrative numerical example is presented to prove feasibility of the proposed approaches.

scholarly journals Novel Adaptive Sliding Mode Control with Nonlinear Disturbance Observer for SMT Assembly Machine

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Rongrong Qian ◽  
Minzhou Luo ◽  
Yao Zhao ◽  
Jianghai Zhao
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Adaptive Sliding Mode Control ◽  
Sliding Surface ◽  
Parameter Uncertainties ◽  
Nonlinear Disturbance Observer ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Nonlinear Disturbance

This paper presents a novel adaptive sliding mode control based on nonlinear sliding surface with disturbance observer (ANSMC-DOB) for precision trajectory tracking control of a surface mount technology (SMT) assembly machine. A two-degree-of-freedom model with time-varying parameter uncertainties and disturbances is built to describe the first axial mode of the pick-place actuation axis of the machine. According to the principle of variable damping ratio coefficient which makes the system have a nonovershoot transient response and a short settling time in the second-order system, the nonlinear sliding surface is designed for the sliding mode control (SMC). Since the upper bound value of the disturbances is unknown, the adaptive gain estimation is applied to replace the switching gain in the SMC. In order to settle the problem of SMC unrobust to the mismatched parameter uncertainties and disturbances, the nonlinear disturbance observer is introduced to estimate the mismatched disturbances and form the novel controller of ANSMC-DOB. The stability of sliding surfaces and control laws are verified by the Lyapunov functions. The simulation research and comparative experiments are conducted to verify the improvement of positioning accuracy and robustness by the proposed ANSMC-DOB in the SMT assembly machine.

scholarly journals Improved Model-Free Sliding Mode Control Algorithm for Control Non-Linear Systems

2020 ◽  
Vol 27 (4) ◽  
pp. 79-89
Author(s):  
Hasnaa Wasouf ◽  
Jomana Diab
Keyword(s):  
Sliding Mode Control ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Control Signal ◽  
Direct Lyapunov Method ◽  
Mode Control ◽  
Model Free ◽  
Non Linear ◽  
The Stability ◽  
Non Linear System

When testing the performance of the model-free sliding mode control algorithm, it was found that it could not maintain good performance when the system was exposed to noise. this research suggests designing a noise-resistant model-free sliding mode control algorithm. The importance of this algorithm is that it takes into account the effect of the noise, where the noise value is implemented in the model-free algorithm. The sliding surface of the controller is designed based on the improved relationship and to ensure the stability of the system in the closed-loop the control signal was derived based on the direct Lyapunov method. To minimize the effects of chattering in the control signal, the control law was reconfigured using a boundary layer. The improved algorithm was implemented to a second-order non-linear system and the simulation results showed the system's ability to track the desired signal in spite of the presence of the noise as well as its ability to maintain the stability of the controlled system

Design of an adaptive chattering avoidance global sliding mode tracker for uncertain non-linear time-varying systems

2016 ◽  
Vol 39 (10) ◽  
pp. 1547-1558 ◽  
Author(s):  
Saleh Mobayen ◽  
Fairouz Tchier
Keyword(s):  
Sliding Mode Control ◽  
Tracking Control ◽  
Sliding Mode ◽  
Linear Time ◽  
Time Varying ◽  
Mode Control ◽  
Global Sliding Mode Control ◽  
Non Linear ◽  
Time Varying Systems ◽  
Non Linear System

In this paper, a novel adaptive global sliding mode control technique is suggested for the tracking control of uncertain and non-linear time-varying systems. The proposed scheme composed of a global sliding mode control structure to eliminate reaching mode and an adaptive tracker to construct the auxiliary control term for eliminating the impacts of unwanted perturbations. Using the Lyapunov direct method, the tracking control of the non-linear system is guaranteed. Moreover, superior position tracking performance is obtained, the control effort is considerably decreased and the chattering phenomenon is removed. Furthermore, using adaptation laws, information about the upper bounds of the system perturbations is not required. To indicate the effectiveness of the suggested scheme, three simulation examples are presented. Simulation results demonstrate the superiority and capability of the offered control law to improve the transient performance of a closed-loop system using online adaptive parameters.

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