Design of Adaptive Fractional-Order Fixed-Time Sliding Mode Control for Robotic Manipulators

Abstract

In this investigation, the adaptive fractional-order non-singular fixed-time terminal sliding mode (AFoFxNTSM) control for the uncertain dynamics of robotic manipulators with external disturbances is introduced. The idea of fractional-order non-singular fixed-time terminal sliding mode (FoFxNTSM) control is presented as the initial step. This approach, which combines the benefits of a fractional-order parameter with the advantages of NTSM, gives rapid fixed-time convergence, non-singularity, and chatter-free control inputs. After that, an adaptive control strategy is merged with the FoFxNTSM, and the resulting model is given the label AFoFxNTSM. This is done in order to account for the unknown dynamics of the system, which are caused by uncertainties and bounded external disturbances. The Lyapunov analysis reveals how stable the closed-loop system is over a fixed time. The pertinent simulation results are offered here for the purposes of evaluating and illustrating the performance of the suggested scheme applied on a PUMA 560 robot.

Mixed Integer Nonlinear Programming-Based Unit Commitment of Conventional Thermal Generators Using Hybrid Evolutionary Algorithms

“…Moreover, the sensitivity to initial conditions and the interpretability of the algorithm's decision-making process remain significant considerations. However, the adaptive control techniques [28] used in robotic manipulator control could inspire adaptive mechanisms within the hybrid evolutionary algorithm. By incorporating adaptive strategies, the algorithm could dynamically adjust its parameters or search strategies during the optimization process.…”

Model‐free based adaptive finite time control with multilayer perceptron neural network estimation for a 10 DOF lower limb exoskeleton

“…The time required for a dynamical system to converge in finite time varies with the nonlinear system, 45 and to achieve the control objective of the exoskeleton, the use of a nonsingular fast terminal sliding surface, as described in Reference 46, is being considered, with the equation used to represent the sliding surface as follows. $$$$ S=e+{\sigma}_1{e}^{\left[\varphi \right]}\kern0.5em +{\sigma}_2{\dot{e}}^{\left[l/p\right]}, $$$$ where, $$$ {\sigma}_1 $$$ and $$$ {\sigma}_2 $$$ are positive constants.…”

Continuous Adaptive Finite-Time Sliding Mode Control for Fractional-Order Buck Converter Based on Riemann-Liouville Definition

“…Traditional control methods have been ineffective in suppressing mismatched disturbances. To address the uncertainties and disturbances in Buck converters and enhance controller performance, researchers have proposed various control strategies, including adaptive control [ 12 ], model predictive control [ 13 ], robust control [ 14 ], and sliding mode control (SMC) [ 15 , 16 , 17 ]. Among these methods, SMC has garnered significant attention for its inherent robustness and simple structure.…”

“… Compared with [ 18 , 25 , 26 ], a globally finite-time stability is achieved in this paper. Compared with [ 17 , 20 , 22 , 24 ], a continuous sliding mode control input is developed to attenuate the chattering caused by the traditional discontinuous sign function. …”

“…Compared with [ 17 , 20 , 22 , 24 ], a continuous sliding mode control input is developed to attenuate the chattering caused by the traditional discontinuous sign function.…”