McKibben-type Artificial Muscle Research Articles

Development and Evaluation of Arm Lifting Assist Devices

Musculoskeletal disorders are common occupational diseases that have become a major social problem. Mechanization has been promoted as a solution to this problem. However, several tasks still require manual labor, such as fruit harvesting in orchards, making the introduction of machinery difficult in many cases. Recently, from the viewpoint of worker protection and ergonomics, various wearable robots for work support have attracted attention. In Europe and the US, there has been much development of arm-lifting assistive devices that support upward work while holding tools in the hands for industrial applications. However, most of the devices currently on the market are expensive compared to their assistive capabilities. Against this background, we developed three types of arm-lifting assistive devices with different concepts (an exoskeleton arm-lifting assistive device utilizing a gas spring, an exoskeleton arm-lifting assistive device utilizing McKibben-type artificial muscles, and an arm-lifting assistive suit utilizing rubber) to develop inexpensive, high-power devices. Furthermore, comparative verification of the assist effectiveness of each device was conducted.

MPC for Artificial Muscles Using FRIT based Optimized Pseudo Linearization Model

A McKibben-type artificial muscle exhibits strong asymmetric hysteresis characteristics. In a previous study, fictitious reference iterative tuning (FRIT) was applied to a 1-DOF rotational actuator applying these muscles because it was able to determine the controller parameters using only a pair of single closed-loop data. However, it is generally difficult to design a reference model properly without information on the plant, which is strongly related to the control performance, and sometimes this leads to performance degradation. To solve this problem, in this study, we propose a method combining FRIT and model predictive control (MPC). First, we define the pseudo linearization (PL) model, which is adopted as a predictor in MPC, and is used to optimization between the model and design a control system by matching the closed-loop system to the PL model using FRIT. Additionally, it can consider input constraints by combined MPC.

Development of Endoskeleton Type Knee Joint Assist Orthosis Using McKibben Type Artificial Muscle

The Japanese agriculture industry, faced with the problem of declining and aging farmers, has keenly called for the development of body assist orthoses for aiding agricultural workers. Therefore, in this study, we propose an endoskeleton-type knee joint assist orthosis for assisting knee joints in half-sitting postures or crouching postures. The proposed endoskeleton-type knee joint assist orthosis uses two McKibben-type artificial muscles per leg and four in total, placed from the waist to the foot along the forward part of the leg to generate assisting power. With the proposed orthosis in use, the contraction forces generated by the McKibben-type artificial muscles are converted into torque via the knees to assist the knee joints. This paper first presents the appearance of the prototyped endoskeleton-type knee joint assist orthosis, and then describes its components and the McKibben-type artificial muscles. To verify its actual effects on muscles, we conducted fitting experiments using a surface myoelectric electrometer to determine its assisting effects; these effects were found on certain experimental subjects, but there were no tangible effects on others. The experimental results suggest that the prototyped endoskeleton-type knee joint assist orthosis requires further improvement.

High-Dorsiflexion Assistive System for Passive Swing Phase Dorsiflexion Training and Preventing Compensatory Movements

Over the last few years, numerous robotic ankle-foot orthoses have been developed to help stroke patients optimize gait rehabilitation. In this paper, we present a study on the effects of assistance on dorsiflexion-restricted gait. Our high-dorsiflexion assistive system aims to provide full assistance to realize passive training of dorsiflexion during the swing phase and prevent compensatory movements. This system, which includes a McKibben-type artificial muscle and an air source, is lightweight and provides a high-dorsiflexion torque. The device could help boost overground gait rehabilitation in stroke patients. With this system, we conducted an experiment on five healthy participants whose dorsiflexion movements were restricted, and the extent of their compensatory movements differed. The results of the processed surface electromyography data differed significantly when dorsiflexion movement was assisted by our system. The spatial parameters also showed significantly improved compensatory movement inclination with sufficient assistance. These results indicate the potential of our system to assist in passive training of ankle dorsiflexion movements and to prevent incorrect gait in patients with low dorsiflexion abilities.

Development of the Arm Support Device using McKibben Type Artificial Muscle

Development of the Arm Support Device using McKibben Type Artificial Muscle

A Simple Method for Manufacturing Planar McKibben-Type Artificial Muscles that Fit into Robotic Surfaces

A Simple Method for Manufacturing Planar McKibben-Type Artificial Muscles that Fit into Robotic Surfaces

Evaluation of an Assist Suit with Actuator which Connected McKibben Type Artificial Muscle and Woven Rubber

Evaluation of an Assist Suit with Actuator which Connected McKibben Type Artificial Muscle and Woven Rubber

Actuation of untethered pneumatic artificial muscles and soft robots using magnetically induced liquid-to-gas phase transitions.

Pneumatic artificial muscles have been widely used in industry because of their simple and relatively high-performance design. The emerging field of soft robotics has also been using pneumatic actuation mechanisms since its formation. However, these actuators/soft robots often require bulky peripheral components to operate. Here, we report a simple mechanism and design for actuating pneumatic artificial muscles and soft robotic grippers without the use of compressors, valves, or pressurized gas tanks. The actuation mechanism involves a magnetically induced liquid-to-gas phase transition of a liquid that assists the formation of pressure inside the artificial muscle. The volumetric expansion in the liquid-to-gas phase transition develops sufficient pressure inside the muscle for mechanical operations. We integrated this actuation mechanism into a McKibben-type artificial muscle and soft robotic arms. The untethered McKibben artificial muscle generated actuation strains of up to 20% (in 10 seconds) with associated work density of 40 kilojoules/meter3, which favorably compares with the peak strain and peak energy density of skeletal muscle. The untethered soft robotic arms demonstrated lifting objects with an input energy supply from only two Li-ion batteries.

Identification of Spring Coefficient for Heel Rocker Function Support Based on Estimated Dorsiflexion Torque.

In previous research, we have developed a high-dorsiflexion assistive robotic technology aiming for gait rehabilitation targeting on ankle dorsiflexion movement. A McKibben-type artificial muscle is applied to provide large dorsiflexion force while adding little weight to the device. This ensures the foot clearance before initial stance phase in gait. Meanwhile, a tension spring is deployed in series with the artificial muscle to support heel rocker function in loading response phase. Suitable spring coefficient for each individual differs according to ankle's dorsiflexion torque in loading response. An unsuitable spring would lead to knee deviation in this phase. In this study, we derived an identification equation to determine a suitable spring coefficient for individuals based on estimation of dorsiflexion torque required to support. An evaluation test on healthy objects was conducted, which shows no negative effects on participants' knee angles with the identified spring coefficient.

Development of power assist suit using McKibben type artificial muscle with outer diameter sensor

Development of power assist suit using McKibben type artificial muscle with outer diameter sensor

Development of a McKibben type artificial muscle with less air consumption for power assist suit used in nursing care

Development of a McKibben type artificial muscle with less air consumption for power assist suit used in nursing care

Design of powered upper limb prosthesis for children using small diameter McKibben type artificial muscle

Design of powered upper limb prosthesis for children using small diameter McKibben type artificial muscle

収縮特性が変更可能ならせん状形状記憶ポリマー複合McKibben型人工筋肉

A McKibben type artificial muscle consists of a rubber tube and knitted fibers, by applying pneumatic pressure it generates contraction displacement in the axial direction. Depending on the knitting angle of the fibers, contraction ratio is varied. On the other hand, Shape Memory Polymer (SMP) is known as a functional polymer having two characteristics of shape fixity and shape recovery. Combining SMP with McKibben type artificial muscle, it is possible to change the knitting angle by using shape fixation.In this study, SMP helical fibers were molded and the McKibben artificial muscle using them were fabricated. This artificial muscle realizes change of fiber angle after production. As a result, it was possible to change the contraction characteristics of the artificial muscle.

Analysis and Modeling of Tap-Water/Pneumatic Drive McKibben Type Artificial Muscles

Analysis and Modeling of Tap-Water/Pneumatic Drive McKibben Type Artificial Muscles

New concept and fundamental experiments of a smart pneumatic artificial muscle with a conductive fiber

A McKibben artificial muscle consisting of a rubber tube and a mesh sleeve made from fibers is a promising actuator as an artificial muscle because of its high power, low weight, and flexibility. However, an external pressure sensor or an expensive electro/pneumatic regulator is generally required to control the pneumatic pressure to drive the actuator.A novel smart McKibben-type artificial muscle with a pressure-sensing function has been proposed and developed in this study. One fiber on the sleeve of the actuator is converted from a normal to a conductive material. The applied pressure is estimated by observing the electrical resistance of the conductive fiber. Therefore, the fiber works as both a sensor and an actuator element.The fabrication process of the smart artificial muscle is established in this report, and the basic characteristics are clarified. Moreover, a compact driving control system of the smart artificial muscle, which uses a small rotary pump without external sensors, electro/pneumatic regulator, or valves, is proposed.

1A1-P04 腰補助用マッスルスーツの評価 : 近赤外分光法(NIRS)を用いた筋疲労評価

Advances in science and technology have helped people ease the extreme physical burden. However, hard labor which is difficult to mechanize and automate still exists. In order to assist human motion, we have been developing a compact and light weight "Muscle Suit" which uses reliable McKibben type artificial muscles. In particular, the development of the Muscle Suit that specializes in back support is urgent. And the evaluation of effectiveness of the Muscle Suit will become a key point on the development of the Muscle Suit. In this study, we report the evaluation of the back support Muscle Suit using near-infrared spectroscopy (NIRS) and electromyogram (EMG).

Development of an Underactuated 2-DOF Wrist Joint using McKibben PAMs

In this work, model of an underactuated 2-DOF wrist joint with pneumatically actuated muscles is proposed. For the joint, McKibben-type artificial muscles are used in parallel configuration for the actuation. For each Degree of Freedom (DOF) one agonist-antagonist pair arrangement is usually used with a pulley mechanism. A mathematical model of wrist joint is derived using conventional forward kinematic analysis. The static model relating pressure in the muscle with the orientation of the wrist joint is obtained by combining the experimental data and mathematical model. Regulation of pressure can be achieved by pulse width modulation control of on/off solenoid valves. A set of free vibration experiments are done for the dynamic identification of the muscle characteristics.

910 4脚歩行ロボットの開発 : McKibben型人工筋によって駆動される脚部の試作

910 4脚歩行ロボットの開発 : McKibben型人工筋によって駆動される脚部の試作

2P1-H06 近赤外分光法による筋疲労評価 : マッスルスーツの開発と評価(感覚・運動・計測(3))

In order to assist human motion, we have been developing a compact and light weight "Muscle Suit" which uses reliable McKibben type artificial muscles. The Muscle Suit physically supports the physical load of the wearer, and has high versatility and conveyance. The evaluation of effectiveness will become a key point on the development of the Muscle Suit. In this study, we used near-infrared spectroscopy (NIRS) to indirectly measure the serum oxygenated hemoglobin and deoxygenated hemoglobin concentration of wearer's regional muscle, newly defined ΔHbts, and evaluate the degree of fatigue.

突発的な負荷を考慮した6自由度人工筋肉マニピュレータの手先剛性制御

Robots have entered human life, and closer relationships are being formed between humans and robots. It is desirable that these robots be flexible and lightweight. For this reason, we studied and developed an artificial muscle actuator using straight-fiber-type artificial muscles derived from the McKibben-type muscles, which have excellent contraction rate and force characteristics. Therefore, we developed a 6-DOF artificial muscle manipulator, which has a wider moveable range than that using McKibben-type artificial muscle. However, this manipulator vibrates when receiving a sudden load, because the artificial muscle is flexible. For this problem, we suggest that control of joint stiffness is effective. In this paper, we controlled joint stiffness of the 6-DOF artificial muscle manipulator, and obtained a compliance ellipse of the end-effector. In addition, this manipulator controlled vibration of the end-effector by changing joint stiffness depending on the position of the end-effector.