scholarly journals Design of Hybrid Phase Sliding Mode Control Scheme for Lower Extremity Exoskeleton

2019 ◽  
Vol 9 (18) ◽  
pp. 3754
Author(s):  
Lingling Chen ◽  
Chao Wang ◽  
Jie Wang ◽  
Xiaowei Song
Keyword(s):  
Lower Extremity ◽  
Sliding Mode Control ◽  
Sliding Mode ◽  
Artificial Muscle ◽  
Phase Changes ◽  
Working Environment ◽  
Phase Detector ◽  
Pneumatic Artificial Muscle ◽  
Mode Control ◽  
Control Scheme

Aiming at a pneumatic artificial muscle (PAM) lower extremity exoskeleton, a control mechanism based on hybrid phase sliding mode control (SMC) is proposed. First of all, the human gait cycle is mainly divided into the swing phase and stance phase, and the lower extremity exoskeleton phase models are established by the Euler–Lagrange method, respectively. Secondly, the lower limb exoskeleton is inevitably affected in the diverse working environment, and the exoskeleton model has nonlinear and strong coupling characteristics, which both increase the control difficulty. In this situations, a robust sliding mode control method is designed based on an Extended State Observer (ESO). Thirdly, the pneumatic muscle takes time to contract and relax, and then the joint input torque cannot jump when the gait phase changes, hence, the smoothing switching of the assistive control scheme is introduced to solve it. The smoothing switching time is detected by a phase detector, and the phase detector is designed by the plantar pressure information. Finally the comparative simulation shows that this control strategy has the advantages of fast time, high control precision and no jump during control torque switching. Pneumatic artificial muscle contraction rate curve shows that the pneumatic muscles’ motion range meets the control requirement of the exoskeleton.

scholarly journals New approach of sliding mode control for nonlinear uncertain pneumatic artificial muscle manipulator enhanced with adaptive fuzzy estimator

2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877320 ◽  
Author(s):  
Ho Pham Huy Anh ◽  
Cao Van Kien ◽  
Nguyen Ngoc Son ◽  
Nguyen Thanh Nam
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Artificial Muscle ◽  
Pneumatic Artificial Muscle ◽  
Fuzzy Sliding Mode Control ◽  
Adaptive Fuzzy ◽  
Mode Control ◽  
Adaptive Fuzzy Sliding Mode ◽  
Fuzzy Sliding Mode

A new enhanced adaptive fuzzy sliding mode control approach is proposed in this article with its good availability for application in control of a highly uncertain nonlinear two-link pneumatic artificial muscle manipulator. Stability demonstration of the robust convergence of the closed-loop pneumatic artificial muscle manipulator system based on a novel enhanced adaptive fuzzy sliding mode control is experimentally proved using Lyapunov stability theorem. Obtained result confirms that the new enhanced adaptive fuzzy sliding mode control method, applied to the two-link uncertain nonlinear pneumatic artificial muscle manipulator system, is fully investigated with better robustness and precision than the standard sliding mode control and fuzzy sliding mode control techniques.

scholarly journals Adaptive Sliding Mode Control Based on Equivalence Principle and Its Application to Chaos Control in a Seven-Dimensional Power System

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Jiangbin Wang ◽  
Ling Liu ◽  
Chongxin Liu ◽  
Xiaoteng Li
Keyword(s):  
Sliding Mode Control ◽  
Power System ◽  
Design Process ◽  
Equivalence Principle ◽  
Sliding Mode ◽  
Chaotic Oscillation ◽  
Adaptive Sliding Mode Control ◽  
Adaptive Sliding Mode ◽  
Mode Control ◽  
Control Scheme

The main purpose of the paper is to control chaotic oscillation in a complex seven-dimensional power system model. Firstly, in view that there are many assumptions in the design process of existing adaptive controllers, an adaptive sliding mode control scheme is proposed for the controlled system based on equivalence principle by combining fixed-time control and adaptive control with sliding mode control. The prominent advantage of the proposed adaptive sliding mode control scheme lies in that its design process breaks through many existing assumption conditions. Then, chaotic oscillation behavior of a seven-dimensional power system is analyzed by using bifurcation and phase diagrams, and the proposed strategy is adopted to control chaotic oscillation in the power system. Finally, the effectiveness and robustness of the designed adaptive sliding mode chaos controllers are verified by simulation.

scholarly journals A Novel Adaptive Super-Twisting Sliding Mode Control Scheme with Time-Delay Estimation for a Single Ducted-Fan Unmanned Aerial Vehicle

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Minh-Thien Tran ◽  
Dong-Hun Lee ◽  
Soumayya Chakir ◽  
Young-Bok Kim
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Unmanned Aerial Vehicle ◽  
Sliding Mode ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Mode Control ◽  
Ducted Fan ◽  
Control Scheme ◽  
Aerial Vehicle

This article proposes a novel adaptive super-twisting sliding mode control scheme with a time-delay estimation technique (ASTSMC-TDE) to control the yaw angle of a single ducted-fan unmanned aerial vehicle system. Such systems are highly nonlinear; hence, the proposed control scheme is a combination of several control schemes; super-twisting sliding mode, TDE technique to estimate the nonlinear factors of the system, and an adaptive sliding mode. The tracking error of the ASTSMC-TDE is guaranteed to be uniformly ultimately bounded using Lyapunov stability theory. Moreover, to enhance the versatility and the practical feasibility of the proposed control scheme, a comparison study between the proposed controller and a proportional-integral-derivative controller (PID) is conducted. The comparison is achieved through two different scenarios: a normal mode and an abnormal mode. Simulation and experimental tests are carried out to provide an in-depth investigation of the performance of the proposed ASTSMC-TDE control system.

scholarly journals A Parameter Independent Stator Current Space-Vector Reference Frame-Based Sensorless IPMSM Drive Using Sliding Mode Control

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2365
Author(s):  
Mohammadreza Moradian ◽  
Jafar Soltani ◽  
Mohamed Benbouzid ◽  
Abbas Najjar-Khodabakhsh
Keyword(s):  
Sliding Mode Control ◽  
Reference Frame ◽  
Sliding Mode ◽  
Rotor Speed ◽  
Space Vector ◽  
Stator Current ◽  
Mode Control ◽  
Control Scheme ◽  
Stator Flux ◽  
Stator Resistance

In this paper, a sliding mode control is presented for direct torque and stator flux control of interior permanent magnet synchronous motor in a rotor speed sensorless drive system. The control scheme is developed in a specific synchronous rotating reference frame (X-Y) in which the stator current space vector coincides with the direct (X) axis. For this control technique no need to have any knowledge of machine parameters such as stator two-axis inductances, rotor permanent magnets flux linkage, and even the rotor initial position. However, the on-line actual stator resistance value is required to estimate the stator flux components in the stator stationary two-axis reference frame. In this control strategy, two simple methods are described for estimating the rotor speed and stator resistance. Some simulation and experimental results are presented to support the validity and effectiveness of the proposed control scheme.

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