Optimised sliding mode control for MIMO uncertain non‐linear system with mismatched disturbances

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.

Download Full-text

An adaptive fuzzy sliding mode control under model uncertainties and disturbances: second-order non-linear system

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-021-03244-6 ◽

2021 ◽

Vol 43 (12) ◽

Author(s):

Shokoufe Tayyebi

Keyword(s):

Linear System ◽

Sliding Mode Control ◽

Sliding Mode ◽

Second Order ◽

Model Uncertainties ◽

Fuzzy Sliding Mode Control ◽

Adaptive Fuzzy Sliding Mode ◽

Non Linear ◽

Fuzzy Sliding Mode ◽

Non Linear System

Download Full-text

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

Association of Arab Universities Journal of Engineering Sciences ◽

10.33261/https://doi.org/10.33261/jaaru.2020.27.4.008 ◽

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

Download Full-text

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

Transactions of the Institute of Measurement and Control ◽

10.1177/0142331216644046 ◽

2016 ◽

Vol 39 (10) ◽

pp. 1547-1558 ◽

Cited By ~ 38

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.

Download Full-text