scholarly journals Design and testing of a soft parallel robot based on pneumatic artificial muscles for wrist rehabilitation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yaxi Wang ◽  
Qingsong Xu
Keyword(s):  
Experimental Testing ◽  
Kinematic Model ◽  
Parallel Robot ◽  
Artificial Muscles ◽  
Rehabilitation Robot ◽  
Soft Robot ◽  
Rehabilitation Training ◽  
Post Surgery ◽  
Flexion Extension ◽  
Pneumatic Artificial Muscles

AbstractWrist rehabilitation is needed to help post-stroke and post-surgery patients recover from wrist fracture or injury. Traditional rehabilitation training is conducted by a therapist in a hospital, which hinders timely treatment due to the corresponding time and space constraints. This paper presents the design and implementation of a soft parallel robot for automated wrist rehabilitation. The presented wrist rehabilitation robot integrates the advantages of both soft robot and parallel robot structures. Unlike traditional rigid-body based rehabilitation robots, this soft parallel robot exhibits a compact structure, which is highly secure, adaptable, and flexible and thus a low-cost solution for personalized treatment. The proposed soft wrist-rehabilitation robot is driven by six evenly distributed linear actuators using pneumatic artificial muscles and one central linear electric motor. The introduced parallel-kinematic mechanism design enables the enhancement of the output stiffness of the soft robot for practical use. An electromyography sensor is adopted to provide feedback signals for evaluating the rehabilitation training process. A kinematic model of the designed robot is derived, and a prototype is fabricated for experimental testing. The results demonstrate that the developed soft rehabilitation robot can assist the wrist to realize all the required training motions, including abduction-adduction, flexion-extension, and supination-pronation. The compact and lightweight structure of this novel robot makes it convenient to use, and suitable rehabilitation training modes can be chosen for tailored rehabilitation at home or in a hospital.

scholarly journals Motion planning of rigid chain for rigid–flexible coupled robot

2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877281 ◽  
Author(s):  
Keyi Wang ◽  
Pengcheng Yin ◽  
Haipeng Yang ◽  
Lan Wang
Keyword(s):  
Motion Planning ◽  
Lower Limb ◽  
Kinematic Model ◽  
Parallel Robot ◽  
Lower Limbs ◽  
Influence Coefficient ◽  
Rehabilitation Robot ◽  
Rehabilitation Training ◽  
Branched Chain ◽  
Branched Chains

This work is motivated by the possibility that hemiplegic patients might achieve complete functional recovery of lower limb joints, muscles, and nerves by stretching and bending the lower limbs using rehabilitation training. A model of a rigid–flexible coupled lower limb rehabilitation robot is established and mechanically analyzed to satisfy both the control of various movement loci with flexion and extension and the requirements of rehabilitation training. According to the Denavit–Hartenberg method and the influence coefficient method, a kinematic model is established. Moreover, a static equilibrium equation is presented, and two motion planning methods for rigid branched chain movement are put forward. Fluctuation parameters are proposed to estimate the tension of every wire. A planning strategy of different rigid branched chains is analyzed during mechanical simulation using MATLAB [version 2013a]/SimMechanics along a specific trajectory. The law of wires and rigid branched chains is achieved. The wires’ working performance of a parallel robot can be improved by introducing a rigid branched chain. During the dynamic simulation of the mechanism, other wires’ tension changes are analyzed by setting the wire’s tension (100 N) of a coupled branched chain. The wire’s tension performance in the system is evaluated by its fluctuation performance. Finally, it is validated that the strategy of angle bisection is the best. The results prove that the rigid–flexible parallel rehabilitation robot can realize gait rehabilitation training of lower limbs, which leads to the servo control research of this robot.

scholarly journals Dynamic Turning of a Soft Quadruped Robot by Changing Phase Difference

2021 ◽  
Vol 8 ◽  
Author(s):  
Hiroaki Tanaka ◽  
Tsung-Yuan Chen ◽  
Koh Hosoda
Keyword(s):  
Phase Difference ◽  
Quadruped Robot ◽  
Artificial Muscles ◽  
Soft Robot ◽  
Contact Pattern ◽  
Soft Body ◽  
Pneumatic Artificial Muscles ◽  
Left And Right ◽  
Body Dynamic ◽  
Robot Body

Dynamic locomotion of a quadruped robot emerges from interaction between the robot body and the terrain. When the robot has a soft body, dynamic locomotion can be realized using a simple controller. This study investigates dynamic turning of a soft quadruped robot by changing the phase difference among the legs of the robot. We develop a soft quadruped robot driven by McKibben pneumatic artificial muscles. The phase difference between the hind and fore legs is fixed whereas that between the left and right legs is changed to enable the robot to turn dynamically. Since the robot legs are soft, the contact pattern between the legs and the terrain can be varied adaptively by simply changing the phase difference. Experimental results demonstrate that changes in the phase difference lead to changes in the contact time of the hind legs, and as a result, the soft robot can turn dynamically.

Design of Active Feedback for Rehabilitation Robot

2014 ◽  
Vol 611 ◽  
pp. 529-535 ◽  
Author(s):  
Marcel More ◽  
Ondrej Liska
Keyword(s):  
Strain Measurement ◽  
Artificial Muscles ◽  
Rehabilitation Robot ◽  
Sensor Systems ◽  
Advantages And Disadvantages ◽  
Pneumatic Artificial Muscles ◽  
Active Feedback ◽  
The Difference

Sensor systems are an essential part of automated equipment. They are even more important in machines that come in contact with people, because they have a significant impact on safety. This paper describes the design of active feedback for rehabilitation device driven by pneumatic artificial muscles. Here are presented three methods for measuring the load of the robot. The first is a system composed of Force Sensitive Resistors (FSR) placed in the handle of the device. Two other methods are intended to measure the load of the actuator composed of artificial muscles. The principle of one method is to measure the difference in filling pressures of the muscles, second is based on strain measurement in the drive cables. The paper describes advantages and disadvantages of using each of these methods in a rehabilitation device.

Powering a Lower Limb Exoskeleton Using Pneumatic Artificial Muscles

2016 ◽  
Author(s):  
Jonathan M. Chambers ◽  
Craig R. Carignan ◽  
Norman M. Wereley
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
Kinematic Model ◽  
Knee Joints ◽  
Transmission Model ◽  
Artificial Muscles ◽  
Lower Limb Exoskeleton ◽  
Actuation System ◽  
Pneumatic Artificial Muscles ◽  
Assembly Tasks

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.

scholarly journals Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles

2006 ◽  
Vol 3 (3) ◽  
pp. 191-197 ◽  
Author(s):  
N. Saga ◽  
J. Nagase ◽  
T. Saikawa
Keyword(s):  
Weight Ratio ◽  
Artificial Muscle ◽  
Human Muscle ◽  
Wearable Device ◽  
Artificial Muscles ◽  
Rehabilitation Robot ◽  
Contraction Rate ◽  
Highly Nonlinear ◽  
Pneumatic Artificial Muscles ◽  
Human Muscles

This article reports the pneumatic artificial muscles based on biomechanical characteristics of human muscles. A wearable device and a rehabilitation robot that assist a human muscle should have characteristics similar to those of human muscle. In addition, since the wearable device and the rehabilitation robot should be light, an actuator with a high power to weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Therefore, an artificial muscle actuator has been developed in which high-strength carbon fibres have been built into the silicone tube. However, its contraction rate is smaller than the actual biological muscles. On the other hand, if an artificial muscle that contracts axially is installed in a robot as compactly as the robot hand, big installing space is required. Therefore, an artificial muscle with a high contraction rate and a tendon-driven system as a compact actuator were developed, respectively. In this study, we report on the basic structure and basic characteristics of two types of actuators.

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