Design and control strategy of humanoid lower limb exoskeleton driven by pneumatic artificial muscles

Author(s):  
Shilong Wan ◽  
Mingxing Yang ◽  
Ruru Xi ◽  
Xingsong Wang ◽  
Ruiming Qian ◽  
...  
Author(s):  
Jonathan M. Chambers ◽  
Craig R. Carignan ◽  
Norman M. Wereley

Passive leg exoskeletons are currently being investigated for offsetting the weight of tools and other loads from workers performing maintenance and assembly tasks. By providing power-assist to the knee joints with pneumatic artificial muscles (PAMs), a wider range of stances could be used by maintenance workers without drawing significant power. A simplified kinematic model of the exoskeleton is developed, and the array of potential user stance configurations is then bounded. A static analysis is performed to define the torque required for actuation of the knee joint to support the tool loads carried by the exoskeleton. Finally, an exemplary transmission model is used to verify that it is feasible for a PAM to provide the range of motion and forces required for knee joint actuation. Upon demonstration of the viability of PAM actuation, development of an exoskeleton leg prototype is underway to provide validation of the proposed scheme. The knee actuation system will be retrofit to the FORTIS exoskeleton, and tests on its effectiveness will be conducted.


2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668500 ◽  
Author(s):  
Feilong Jiang ◽  
Guoliang Tao ◽  
Qingwei Li

Most robots that are actuated by antagonistic pneumatic artificial muscles are controlled by various control algorithms that cannot adequately imitate the actual muscle distribution of human limbs. Other robots in which the distribution of pneumatic artificial muscle is similar to that of human limbs can only analyze the position of the robot using perceptual data instead of rational knowledge. In order to better imitate the movement of a human limb, the article proposes a humanoid lower limb in the form of a parallel mechanism where muscle is unevenly distributed. Next, the kinematic and dynamic movements of bionic hip joint are analyzed, where the joint movement is controlled by an observer-based fuzzy adaptive control algorithm as a whole rather than each individual pneumatic artificial muscle and parameters that are optimized by a neural network. Finally, experimental results are provided to confirm the effectiveness of the proposed method. We also document the role of muscle in trajectory tracking for the piriformis and musculi obturator internus in isobaric processes.


2021 ◽  
pp. 91-97
Author(s):  
E. A. Kotov ◽  
◽  
A. D. Druk ◽  
D. N. Klypin ◽  
◽  
...  

The article deals with the solution of the problem of optimizing the characteristics of controlled motion of human lower limb exoskeleton robot for improving medical rehabilitation. The aim of the work is to develop a rehabilitation device capable of providing controlled motion in two planes, as well as maintaining balance without loss of mobility. The design and control system of a rehabilitation trainer designed for performing mechanotherapy of the lower limbs of patients with locomotive disorders are proposed and characterized. The developed system has a number of significant differences from analogues and can be recommended for experimental research on patients with impaired locomotive functions


2019 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
Tsung-Chin Tsai ◽  
Mao-Hsiung Chiang

This study determines the practicality and feasibility of the application of pneumatic artificial muscles (PAMs) in a pneumatic therapy robotic system. The novel mechanism consists of a single actuated pneumatic artificial muscle (single-PAM) robotic lower limb that is driven by only one PAM combined with a torsion spring. Unlike most of previous studies, which used dual-actuated pneumatic artificial muscles (dual-PAMs) to drive joints, this design aims to develop a novel single-PAM for a one degree-of-freedom (1-DOF) robotic lower-limb system with the advantage of a mechanism for developing a multi-axial therapy robotic system. The lower limb robotic assisting system uses the stretching/contraction characteristics of a single-PAM and the torsion spring designed by the mechanism to realize joint position control. The joint is driven by a single-PAM controlled by a proportional pressure valve, a designed 1-DOF lower-limb robotic system, and an experimental prototype system similar to human lower limbs are established. However, the non-linear behavior, high hysteresis, low damping and time-variant characteristics for a PAM with a torsion spring still limits its controllability. In order to control the system, a fuzzy sliding mode controller (FSMC) is used to control the path tracking for the PAM for the first time. This control method prevents approximation errors, disturbances, un-modeled dynamics and ensures positioning performance for the whole system. Consequently, from the various experimental results, the control response designed by the joint torsion spring mechanism can also obtain the control response like the design of the double-PAMs mechanism, which proves that the innovative single-PAM with torsion spring mechanism design in this study can reduce the size of the overall aid mechanism and reduce the manufacturing cost, can also improve the portability and convenience required for the wearable accessory, and is more suitable for the portable rehabilitation aid system architecture.


2011 ◽  
Vol 186 ◽  
pp. 31-35 ◽  
Author(s):  
Fei Li ◽  
Yu Wang ◽  
He Ting Tong ◽  
Ray P.S. Han

As a skeletal muscle-like actuator, PAM possesses many unique advantages. They include compliance and high power-to-weight ratio, which make it an ideal actuator for robotic and powered exoskeleton applications. But its flexible braided mesh shell and the compressibility of air make PAM much more difficult to model and control compared to traditional actuators. In this work, the mechanical properties of the McKibben PAM produced by Festo are examined, tested and discussed. The results demonstrate the muscle-like property of PAM and its strong non-linear and hysteresis behaviors. A simple law between the areas of the hysteresis and pressure is proposed, and the relationships of the areas of the hysteresis, external load and the continuous working time are studied. Further, changing the PAM length that is smaller than 0.4 mm may lead to the “crawl” phenomenon. Finally, the empirical results can be used in compensation-based controls of the hysteresis in the McKibben PAM.


Author(s):  
Jian Li ◽  
Diansheng Chen ◽  
Chunjing Tao ◽  
Hui Li

Purpose Many studies have shown that rehabilitation robots are crucial for lower limb dysfunction, but application of many robotics have yet to be seen to actual use in China. This study aimed to improve a lower limb rehabilitation robot by details improving and practical design. Design/methodology/approach Structures and control system of a lower limb rehabilitation robot are improved in detail, including joint calculations, comfort analysis and feedback logic creation, and prototype experiments on healthy individuals and patients are conducted in a hospital. Findings All participating subjects did not experience any problems. The experiment shows detail improving is reasonable, and feasibility of the robot was confirmed, which has potential for overcoming difficulties and problems in practical application. Research limitations/implications Therapeutic effects need to be evaluated in the future. Also, more details should be improved continuously based on the actual demand. Originality/value The improved robot could assist the lower limb during standing or walking, which has significance for practical application and patients in China.


Soft Robotics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 140-154 ◽  
Author(s):  
Jiangbei Wang ◽  
Yanqiong Fei ◽  
Weidong Chen

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