Design of Variable Stiffness Energy Storage Walking Assist Hip Exoskeleton and Simulation of Assistance Effect

doi:10.16182/j.issn1004731x.joss.20-0994

Abstract

Abstract:

Passive energy storage walking assist exoskeleton makes full use of the human’s own energy, reducing energy consumption when walking. Aiming at the present passive energy storage walking assist exoskeleton adopts fixed stiffness joint, a passive variable stiffness energy storage walking assist hip exoskeleton is designed, on the base of joint energy flow characteristics in the process of people walking and the change of stiffness characteristics. The human-exoskeletons coupling model is established, and the optimal stiffness that minimizes the power consumption of the human body walking on a flat surface, as well as the total metabolism and the main thigh muscle force and power change under the variable stiffness conditions are simulated. The result shows that different stiffnesses of the exoskeleton affect the energy consumption during the wearer's walking, and the simulation with the optimal stiffness during lower limb flexion and extension, respectively, can further reduce the energy consumption. The results are an important reference for the stiffness requirements in passive exoskeleton design.

Key words: assist exoskeleton, variable stiffness, hip joint, simulation, metabolism

CLC Number:

TP391.9

Bingshan Hu, Ke Cheng, Sheng Lu, Hongliu Yu. Design of Variable Stiffness Energy Storage Walking Assist Hip Exoskeleton and Simulation of Assistance Effect[J]. Journal of System Simulation, 2022, 34(5): 1090-1100.

Figures/Tables 15

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References 23

[1]	Lovrenovic Z, Doumit M. Development and Testing of a Passive Walking Assist Exoskeleton[J]. Biocybernetics and Biomedical Engineering (S0208-5216), 2019, 39(4): 992-1004.
[2]	韩亚丽, 王兴松. 下肢助力外骨骼的动力学分析及仿真[J]. 系统仿真学报, 2013, 25(1): 61-67.
	Han Yali, Wang Xingsong. Dynamic Analysis and Simulation of Lower Limb Power-Assisted Exoskeleton[J]. Journal of System Simulation, 2013, 25(1): 61-67.
[3]	Zoss A B, Kazerooni H, Chu A. Biomechanical Design of the Berkeley Lower Extremity Exoskeleton (BLEEX)[J]. IEEE/ASME Transactions on Mechatronics (S1083-4435), 2006, 11(2): 128-138.
[4]	Esquenazi A, Talaty M, Packel A, et al. The ReWalk Powered Exoskeleton to Restore Ambulatory Function to Individuals with Thoracic-Level Motor-Complete Spinal Cord Injury[J]. American Journal of Physical Medicine & Rehabilitation (S0894-9115), 2012, 91(11): 911-921.
[5]	Suzuki K, Mito G, Kawamoto H, et al. Intention-Based Walking Support for Paraplegia Patients with Robot Suit HAL[J]. Advanced Robotics (S0169-1864), 2007, 21(12): 1441-1469.
[6]	Chang Y H, Zhang J W, Chen K, et al. Design and Preliminary Evaluation of a Clutch-Spring Lower Limb Exoskeleton[C]//2019 5th International Conference on Control, Automation and Robotics. Beijing: IEEE, 2019: 788-792.
[7]	Walsh C J, Endo K, Herr H. A Quasi-Passive Leg Exoskeleton for Load-Carrying Augmentation[J]. International Journal of Humanoid Robotics (S0219-8436), 2007, 4(3): 487-506.
[8]	Shen Z F, Sam S, Allison G, et al. A Simulation-Based Study on a Clutch-Spring Mechanism Reducing Human Walking Metabolic Cost[J]. International Journal of Mechanical Engineering and Robotics Research (S2278-0149), 2018, 7(1): 55-60.
[9]	Haufe F L, Wolf P, Riener R, et al. Biomechanical Effects of Passive Hip Springs During Walking[J]. Journal of Biomechanics (S0021-9290), 2020, 98: 109432.
[10]	Barazesh H, Sharbafi M A. A Biarticular Passive Exosuit to Support Balance Control can Reduce Metabolic Cost of Walking[J]. Bioinspiration & Biomimetics (S1748-3182), 2020, 15(3): 036009.
[11]	Zhou L B, Chen W H, Chen W J, et al. Design of a Passive Lower Limb Exoskeleton for Walking Assistance with Gravity Compensation[J]. Mechanism and Machine Theory (S0094-114X), 2020, 150: 103840.
[12]	Chen W, Wu S, Zhou T, et al. On the Biological Mechanics and Energetics of the Hip Joint Muscle–Tendon System Assisted by Passive Hip Exoskeleton[J]. Bioinspiration & Biomimetics (S1748-3182), 2018, 14: 016012.
[13]	Levesque L, Doumit M. Study of Human-Machine Physical Interface for Wearable Mobility Assist Devices[J]. Medical Engineering & Physics (S1350-4533), 2020, 80(5): 33-43.
[14]	Kumar S, Zwall M, Bolivar N E, et al. Extremum Seeking Control for Stiffness Auto-Tuning of a Quasi-Passive Ankle Exoskeleton[J]. IEEE Robotics and Automation Letters (S2377-3766), 2020, 5(3): 4604-4611.
[15]	Bovi G, Rabuffetti M, Mazzoleni P, et al. A Multiple-Task Gait Analysis Approach: Kinematic, Kinetic and EMG Reference Data for Healthy Young and Adult Subjects[J]. Gait & Posture (S0966-6362), 2011, 33(1): 6-13.
[16]	Collins S H, Wiggin M B, Sawicki G S. Reducing the Energy Cost of Human Walking Using an Unpowered Exoskeleton[J]. Nature (S0028-0836), 2015, 522(7555): 212-215.
[17]	Panizzolo F A, Bolgiani C, Liddo L D, et al. Reducing the Energy Cost of Walking in Older Adults using a Passive Hip Flexion Device[J]. Journal of NeuroEngineering and Rehabilitation (S1743-0003), 2019, 16(1): 1-9.
[18]	Dembia C L, Silder A, Uchida T K et al. Simulating Ideal Assistive Devices to Reduce the Metabolic Cost of Walking with Heavy Loads[J]. PLoS One (S1932-6203). 2017, 12(7): e0180320.
[19]	Browne M G, Franz J R. More Push from Your Push-off: Joint-Level Modifications to Modulate Propulsive Forces in Old Age[J]. PLoS One (S1932-6203). 2018, 13(8): e0201407.
[20]	Sun J T, Guo Z, Sun D Y, et al. Design, Modeling and Control of a Novel Compact, Energy-Efficient, and Rotational Serial Variable Stiffness Actuator (SVSA-II)[J]. Mechanism and Machine Theory (S0094-114X), 2018, 130: 123-136.
[21]	Wolf S, Eiberger O, Hirzinger G. The DLR FSJ: Energy Based Design of a Variable Stiffness Joint[C]//IEEE International Conference on Robotics and Automation. Shanghai, China: IEEE, 2011: 5082-5089.
[22]	Jafari A, Tsagarakis N G. A New Actuator with Adjustable Stiffness Based on a Variable Ratio Lever Mechanism[J]. IEEE/ASME Transactions on Mechatronics (S1083-4435), 2014, 19(1): 55-63.
[23]	Maryam K, Mehdi E, Mohsen Z. Human-Exoskeleton Control Simulation, Kinetic and Kinematic Modeling and Parameters Extraction[J]. Methods X (S2215-0161), 2019, 6: 1838-1846.

体重/kg	定刚度(Nm/rad)	变刚度(Nm/rad)
60	k=171.9时，代谢减少9%	k₁=103.14，k₂=171.9时代谢减少10%
70	k=114.6时，代谢减少8%	k₁=91.68，k₂=137.52时代谢减少9%