Periodic event-triggered sliding mode control for lower limb exoskeleton based on human–robot cooperation

2021 ◽  
Author(s):  
Jie Wang ◽  
Jiahao Liu ◽  
Gaowei Zhang ◽  
Shijie Guo
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Sliding Mode ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Robot Cooperation ◽  
Event Triggered

Design of M-G modal space sliding mode control for lower limb exoskeleton robot driven by electrical actuators

Mechatronics ◽  
2021 ◽  
Vol 78 ◽  
pp. 102610
Author(s):  
Jinsong Zhao ◽  
Tao Yang ◽  
Zhilei Ma ◽  
Chifu Yang ◽  
Zhipeng Wang ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Sliding Mode ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Exoskeleton Robot ◽  
Modal Space

Fault tolerant control based on backstepping nonsingular terminal integral sliding mode and impedance control for a lower limb exoskeleton

2021 ◽  
pp. 095440622110357
Author(s):  
Majied Mokhtari ◽  
Mostafa Taghizadeh ◽  
Pegah Ghaf Ghanbari
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Impedance Control ◽  
Fault Tolerant Control ◽  
Integral Type ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Control Scheme

In this paper, an active fault-tolerant control scheme is proposed for a lower limb exoskeleton, based on hybrid backstepping nonsingular fast terminal integral type sliding mode control and impedance control. To increase the robustness of the sliding mode controller and to eliminate the chattering, a nonsingular fast terminal integral type sliding surface is used, which ensures finite time convergence and high tracking accuracy. The backstepping term of this controller guarantees global stability based on Lyapunov stability criterion, and the impedance control reduces the interaction forces between the user and the robot. This controller employs a third order super twisting sliding mode observer for detecting, isolating ad estimating sensor and actuator faults. Motion stability based on zero moment point criterion is achieved by trajectory planning of waist joint. Furthermore, the highest level of stability, minimum error in tracking the desired joint trajectories, minimum interaction force between the user and the robot, and maximum system capability to handle the effect of faults are realized by optimizing the parameters of the desired trajectories, the controller and the observer, using harmony search algorithm. Simulation results for the proposed controller are compared with the results obtained from adaptive nonsingular fast terminal integral type sliding mode control, as well as conventional sliding mode control, which confirm the outperformance of the proposed control scheme.

scholarly journals Robust nonsingular fast terminal sliding-mode control for Sit-to-Stand task using a mobile lower limb exoskeleton

2020 ◽  
Vol 101 ◽  
pp. 104496 ◽  
Author(s):  
Joel Hernández Hernández ◽  
Sergio Salazar Cruz ◽  
Ricardo López-Gutiérrez ◽  
Arturo González-Mendoza ◽  
Rogelio Lozano
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Sliding Mode ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Sit To Stand ◽  
Fast Terminal Sliding Mode

scholarly journals Robust Sliding Mode Control for a 2-DOF Lower Limb Exoskeleton Base on Linear Extended State Observer

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Zhenlei CHEN ◽  
Qing GUO ◽  
Yao YAN ◽  
Dan JIANG
Keyword(s):  
Sliding Mode Control ◽  
Lower Limb ◽  
Sliding Mode ◽  
External Disturbance ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Lower Limb Exoskeleton ◽  
Mode Control ◽  
Linear Extended State Observer

For the 2- Degree of Freedom (DOF) lower limb exoskeleton, to ensure the system robustness and dynamic performance, a linear-extended-state-observer-based (LESO) robust sliding mode control is proposed to not only reduce the influence of parametric uncertainties, unmodeled dynamics, and external disturbance but also estimate the unmeasurable real-time joint angular velocity directly. Then, via Lyapunov technology, the stability of the corresponding LESO and controller is proven. The appropriate and reasonable simulation was carried out to verify the effectiveness of the proposed LESO and exoskeleton controller.

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