Task performance-based adaptive velocity assist-as-needed control for an upper limb exoskeleton

Guo, Yida; Wang, Haoping; Tian, Yang; Caldwell, Darwin G.

doi:10.1016/j.bspc.2021.103474

Cited by 11 publications

(6 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At different stages of their rehabilitation, patients need different training modalities, requiring a specific stiffness from the rehabilitation robot ( Zou et al, 2022 ). In order to increase the effectiveness of rehabilitation therapy assisted by rehabilitation robot, patients’ active participation must be encouraged by the robot controller ( Luo et al, 2017 ; Guo et al, 2022a ). At the same time, if the patient’s movement deviated from the expected movement, it should be restrained.…”

Section: Methodsmentioning

confidence: 99%

Research on adaptive impedance control technology of upper limb rehabilitation robot based on impedance parameter prediction

Zhang,

Li,

Tao

et al. 2024

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

Introduction: With the aggravation of aging and the growing number of stroke patients suffering from hemiplegia in China, rehabilitation robots have become an integral part of rehabilitation training. However, traditional rehabilitation robots cannot modify the training parameters adaptively to match the upper limbs’ rehabilitation status automatically and apply them in rehabilitation training effectively, which will improve the efficacy of rehabilitation training.Methods: In this study, a two-degree-of-freedom flexible drive joint rehabilitation robot platform was built. The forgetting factor recursive least squares method (FFRLS) was utilized to estimate the impedance parameters of human upper limb end. A reward function was established to select the optimal stiffness parameters of the rehabilitation robot.Results: The results confirmed the effectiveness of the adaptive impedance control strategy. The findings of the adaptive impedance control studies showed that the adaptive impedance control had a significantly greater reward than the constant impedance control, which was in line with the simulation results of the variable impedance control. Moreover, it was observed that the levels of robot assistance could be suitably modified based on the subject’s different participation.Discussion: The results facilitated stroke patients’ upper limb rehabilitation by enabling the rehabilitation robot to adaptively change the impedance parameters according to the functional status of the affected limb. In clinic therapy, the proposed control strategy may help to adjust the reward function for different patients to improve the rehabilitation efficacy eventually.

show abstract

Section: Methodsmentioning

confidence: 99%

Research on adaptive impedance control technology of upper limb rehabilitation robot based on impedance parameter prediction

Zhang,

Li,

Tao

et al. 2024

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

show abstract

“…To enhance the accuracy performance of the controller and improve the transient and steady response, a barrier Lyapunov function (BLF)-based controller is proposed. 14 The BLF-based controller can preset a boundary, when the constrained variable approaches the preset boundary, the value of the BLF will increase so that the variable remains within the boundary. 15 Due to the above characteristics, the BLF-based control method can preset a boundary for the tracking error, so that the tracking error remains within the preset boundary to achieve the purpose of improving the transient and steady response.…”

Section: Introductionmentioning

confidence: 99%

“…15 Due to the above characteristics, the BLF-based control method can preset a boundary for the tracking error, so that the tracking error remains within the preset boundary to achieve the purpose of improving the transient and steady response. A time-invariant BLF-based controller is proposed for an upper limb exoskeleton, 14 in which the BLF can ensure that the tracking error is within a preset boundary, so as to ensure that the subject's motion trajectory will not exceed the safe range. Then, a time-variant BLF-based controller is proposed for an upper limb exoskeleton, 16 the tracking error was kept in a decreasing boundary by BLF to make the subject's motion trajectory more closely match the desired trajectory.…”

Section: Introductionmentioning

confidence: 99%

“…To enhance the accuracy performance of the controller and improve the transient and steady response, a barrier Lyapunov function (BLF)‐based controller is proposed 14 . The BLF‐based controller can preset a boundary, when the constrained variable approaches the preset boundary, the value of the BLF will increase so that the variable remains within the boundary 15 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Asymmetric time‐varying BLF‐based model‐free hybrid force/position control for SEA‐based 2‐DOF manipulator

Wei

Wang

Tian

2023

Adaptive Control & Signal

Self Cite

View full text Add to dashboard Cite

Summary In this work, an asymmetric time‐varying barrier Lyapunov function‐based model‐free hybrid force/position controller (ABLF‐MFC) is proposed for the series elastic actuator‐based 2‐DOF manipulator. Inspired by large surface machining, many scenarios require hybrid force/position control, and the simple position control can no longer meet the above requirements. Therefore, ABLF‐MFC with a dual‐loop structure is established, which are force sub‐control loop and position sub‐control loop. Based on the idea of admittance control, the force sub‐control loop generates a reference trajectory according to the desired interaction force and trajectory. Then, for the position sub‐control loop, to simplify the controller design process, an ultra‐local model (ULM) is introduced, which can approximate the original system. Since the ULM has an unknown term, time‐delay estimation (TDE) is applied to estimate it, which can also reduce the dependence on accurate model parameters. The position sub‐control loop is designed by an asymmetric time‐varying barrier Lyapunov function, an integral‐type Lyapunov function and an adaptive compensation term, so the tracking error can be kept within the preset boundary while ensuring the convergence, and the TDE estimation error can be compensated. Rigorous mathematical proofs and simulation results verify the effectiveness of ABLF‐MFC.

show abstract

“…In terms of future development, the intention is to control the CardioVR-ReTone robotic exoskeleton with the help of a brain-controlled helmet. The whole iReHave [41], [42] rigid exoskeleton is mounted on a pedestal and the vertical position of the exoskeleton mounting can be adjusted. In order to replicate the human upper limb joints the exoskeleton has seven DOFs: 3 DOFs at the shoulder joint for extension/flexion, adduction/abduction, and external rotation/internal rotation, 1 DOF at the elbow joint for E/F, 1 DOF at the forearm joint for, and 2 DOFs at the wrist.…”

Section: Soft and Rigidmentioning

confidence: 99%

Study of exoskeletons for upper limb rehabilitation

Contreras-González¹

View full text Add to dashboard Cite

show abstract

Task performance-based adaptive velocity assist-as-needed control for an upper limb exoskeleton

Cited by 11 publications

References 36 publications

Research on adaptive impedance control technology of upper limb rehabilitation robot based on impedance parameter prediction

Research on adaptive impedance control technology of upper limb rehabilitation robot based on impedance parameter prediction

Asymmetric time‐varying BLF‐based model‐free hybrid force/position control for SEA‐based 2‐DOF manipulator

Study of exoskeletons for upper limb rehabilitation

Contact Info

Product

Resources

About