Pneumatic Artificial Muscles Based on Biomechanical Characteristics of Human Muscles

Abstract

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.

Operating Characteristics of Antagonistic Actuator with Pneumatic Artificial Muscles

“…The serial element (nonlinear spring) represents muscle internal flexibility and it allows muscle to move quickly from active to passive state. Parallel element (nonlinear spring) represents properties of the tissue that surrounds a muscle; it is a passive force with tendency to return muscle to its original length [22]. Modified Hill´s muscle model is based on this muscle model, it is described in detail in the works [23,24] and its block diagram as a part of the actuator model is shown in Fig.…”

Smart Pneumatic Artificial Muscle Using a Bend Sensor like a Human Muscle with a Muscle Spindle

“…However, it lacked durability because the nylon fibers placed around the rubber would rub and break during driving. Moreover, highly compressed air was necessary to drive it [10][11][12].…”

Dynamic simulation model of pneumatic actuator with artificial muscle

“…To use the muscles as an adjustable spring-dampersystem, it is necessary to have a model of these actuators which describes the whole dynamics for using in advanced control algorithms [2], [3], [4], [5]. For that reason there are many research groups of artificial muscles and their models studied [6], [7], [8], [9].…”