基於前饋補償與肌肉電訊號之比例控制之髖膝下肢動力外骨骼設計與實踐

Design and Implementation of Powered Hip-Knee Lower Limb Exoskeleton based on Feedforward Compensations and EMG Proportional Control

楊嘉祐(Chia-Yu Yang)

指導教授 ： 陳建祥

國立清華大學/工學院/動力機械工程學系/碩士(2020年)

摘要

近年來，感測器的微小化、普及化以及便宜化，促使穿戴式的感測裝置的興起。隨著人口高齡化，還有身體不便以及工業上的需求，使得外骨骼的蓬勃發展。本文延續本實驗室過去所發展的主動式髖膝下肢外骨骼，外骨骼為仿人體下肢的結構，直流馬達與減速機對應到使用者的髖與膝關節。
相較於實驗室過去的發展，本文在外骨骼系統中發展了兩種模式，第一種為隨動模式，其次為輔助模式。隨動模式讓外骨骼在沒有力感測的情況下配合使用者進行移動，此模式主要採用兩種補償策略，一個是摩擦力補償策略，另一個是外骨骼的姿態重力補償。輔助模式是在隨動模式中加入輔助策略，而輔助策略中有兩個輔助力來源，分別為使用者的肌肉電信號與使用者的姿態。透過上述兩種策略便能讓使用者的動作擺脫預先規劃的動作目標，以及獲得輔助。
本文對於主要策略中所採用的模型與演算法進行描述，分別有摩擦力補償、姿態重力補償以及肌肉電信號輔助算法。在摩擦力補償算法中採用抖動信號並結合位置回授以降低減速機位置對摩擦力的影響和增加減速機低速端的力矩變化上的感測；在姿態重力補償中，加入使用者下肢與上半身傾角模型以降低腳底正向力估測的誤差；在肌肉電信號輔助中，提出實時對肌肉電信號去偏壓的算法，並在肌肉電信號的比例控制中加入人體下肢模型，以同時對多關節間進行協助。
在實驗中將所採用的主要策略方法進行實驗並評估。最後，透過將方法實踐於外骨骼系統中，來驗證與說明隨動模式能應用於執行日常動作，以及輔助模式能夠協助使用者。

關鍵字

下肢外骨骼 ； 前饋補償 ； 肌肉電信號 ； 摩擦力補償 ； 比例控制 ； 抖動控制 ； 姿態重力補償

並列摘要

Nowadays, the development of the exoskeletons becomes more and more popular due to the rise of technology that makes the sensing systems smaller, cheaper and widespread, and the needs of the disabled, the elders and the industries. Our lab have dig into the field of active Hip-Knee exoskeleton for a plenty of time. This thesis continues the past researches in our lab and improving the system and performance.
Compare with the former developments, this thesis proposed two modes for the operation of the exoskeleton. One is ‘Follow Mode’, and another is ‘Support Mode’. The main purpose of ‘Follow Mode’ is to let the exoskeleton follow the motion of user without any force sensor. The friction compensation algorithm and the gravity compensation are the main strategies for ‘Follow Mode’. ’Support Mode’ is the mode that exoskeleton is activate in helping the motion of the user. This mode is based on the proportional EMG control and supporting the gravity effect acting on the user. Preprograming motion angles are no longer needed in the operation of the exoskeleton.
In order to verify and discuss the strategies of ‘Follow Mode’ and ‘Support Mode’, the friction model and compensation algorithm, human model for calibrating the normal force of the feet and the support from the EMG are verified and discussed. At last, the experiments of ‘Follow Mode’ and ‘Support Mode’ are done in order to verify the purpose of the modes.

並列關鍵字

Lower Limb Exoskeleton ； Feedforward Compensations ； EMG ； Friction Compensation ； Proportional Control ； Dither Control ； Gravity Compensation

參考文獻

[1] H. Herr, "Exoskeletons and orthoses: classification, design challenges and future directions," Journal of NeuroEngineering and Rehabilitation, vol. 6, no. 1, p. 21, 2009.

[2] C. Yang, J. Zhang, Y. Chen, Y. Dong and Y. Zhang, "A Review of exoskeleton-type systems and their key technologies," Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, vol. 222, no. 8, pp. 1599-1612, 2008.

[3] T. Yan, M. Cempini, C. Oddo and N. Vitiello, "Review of assistive strategies in powered lower-limb orthoses and exoskeletons," Robotics and Autonomous Systems,, vol. 64, pp. 120-136, 2015.

[4] R. Mosher, "Handyman to Hardiman," SAE Technical Paper, 1967.

[5] A. Young and D. Ferris, "State of the Art and Future Directions for Lower Limb Robotic Exoskeletons," IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 25, no. 2, pp. 171-182, 2017.