Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton
Due to some model uncertainties and unknown friction disturbances that exist in the 2-DOF lower limb exoskeleton, a linear extended state observer (LESO) is proposed to estimate the unmeasurable angular velocity of two joints and the lumped uncertainties caused by friction disturbance and hydraulic...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-10-01
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| Series: | Actuators |
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| Online Access: | https://www.mdpi.com/2076-0825/12/11/402 |
| _version_ | 1797460630035234816 |
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| author | Jiyu Zhang Wei Gao Qing Guo |
| author_facet | Jiyu Zhang Wei Gao Qing Guo |
| author_sort | Jiyu Zhang |
| collection | DOAJ |
| description | Due to some model uncertainties and unknown friction disturbances that exist in the 2-DOF lower limb exoskeleton, a linear extended state observer (LESO) is proposed to estimate the unmeasurable angular velocity of two joints and the lumped uncertainties caused by friction disturbance and hydraulic parametric uncertainties. Meanwhile, by using the Lyapunov technique, a sliding mode controller is designed to improve the dynamic performance and the steady state accuracy of two joint angle responses in human–exoskeleton cooperative motion. By regulating the sliding mode controller gain, both the system state errors and estimation errors of the LESO are reduced in an arbitrary boundary of zero neighborhood. Finally, the effectiveness of the proposed control scheme is verified with both simulation and experimental results for one operator-wearable test, to guarantee that the joint position tracking performance and human–exoskeleton impedance torques are suppressed in a satisfactory boundary. |
| first_indexed | 2024-03-09T17:07:48Z |
| format | Article |
| id | doaj.art-ccaf8455ee664b959011bbd7b7d48af4 |
| institution | Directory Open Access Journal |
| issn | 2076-0825 |
| language | English |
| last_indexed | 2024-03-09T17:07:48Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Actuators |
| spelling | doaj.art-ccaf8455ee664b959011bbd7b7d48af42023-11-24T14:22:30ZengMDPI AGActuators2076-08252023-10-01121140210.3390/act12110402Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb ExoskeletonJiyu Zhang0Wei Gao1Qing Guo2School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaSchool of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, ChinaSchool of Aeronautics and Astronautics, University of Electronic Science and Technology of China, Chengdu 611731, ChinaDue to some model uncertainties and unknown friction disturbances that exist in the 2-DOF lower limb exoskeleton, a linear extended state observer (LESO) is proposed to estimate the unmeasurable angular velocity of two joints and the lumped uncertainties caused by friction disturbance and hydraulic parametric uncertainties. Meanwhile, by using the Lyapunov technique, a sliding mode controller is designed to improve the dynamic performance and the steady state accuracy of two joint angle responses in human–exoskeleton cooperative motion. By regulating the sliding mode controller gain, both the system state errors and estimation errors of the LESO are reduced in an arbitrary boundary of zero neighborhood. Finally, the effectiveness of the proposed control scheme is verified with both simulation and experimental results for one operator-wearable test, to guarantee that the joint position tracking performance and human–exoskeleton impedance torques are suppressed in a satisfactory boundary.https://www.mdpi.com/2076-0825/12/11/402lower limb exoskeletonlinear extended state observersliding mode controllumped uncertainty |
| spellingShingle | Jiyu Zhang Wei Gao Qing Guo Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton Actuators lower limb exoskeleton linear extended state observer sliding mode control lumped uncertainty |
| title | Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton |
| title_full | Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton |
| title_fullStr | Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton |
| title_full_unstemmed | Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton |
| title_short | Extended State Observer-Based Sliding Mode Control Design of Two-DOF Lower Limb Exoskeleton |
| title_sort | extended state observer based sliding mode control design of two dof lower limb exoskeleton |
| topic | lower limb exoskeleton linear extended state observer sliding mode control lumped uncertainty |
| url | https://www.mdpi.com/2076-0825/12/11/402 |
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