Double-Acting Sleeve Muscle Actuator for Bio-Robotic Systems

Abstract

This paper presents a new type of muscle-like actuator, namely double-acting (DA) sleeve muscle actuator, which is suitable for the actuation of biologically-inspired and biomedical robotic systems, especially those serving human-assistance purposes (prostheses, orthoses, etc.). Developed based on the traditional pneumatic muscle actuator, the new DA sleeve muscle incorporates a unique insert at the center. With the insert occupying the central portion of the internal volume, this new actuator enjoys multiple advantages relative to the traditional pneumatic muscle, including a consistent increase of force capacity over the entire range of motion, and a significant decrease of energy consumption in operation. Furthermore, the insert encompasses an additional chamber, which generates an extension force when pressurized. As such, this new actuator provides a unique bi-directional actuation capability, and, thus, has a potential to significantly simplify the design of a muscle actuator-powered robotic system. To demonstrate this new actuator concept, a prototype has been designed and fabricated, and experiments conducted on this prototype demonstrated the enhanced force capacity and the unique bi-directional actuation capability.

Control of a Heavy-Lift Robotic Manipulator with Pneumatic Artificial Muscles

“…Looking to other applications, these actuators are particularly desirable in portable robotic systems intended for interaction with humans [1], such as those envisioned for nursing assistance and in casualty extraction. Similar designs with bi-directional capabilities [9] may permit an even greater range of applications.…”

A New Type of Hydraulic Muscle

“…Knowing the external moment about each joint, the stress applied to the hinge membrane can be found using the tension-moment relation in Equation (10) and pressure stress at Equation (7). The corresponding strain was interpolated from the experimental stress-stain curve ( Figure 3) and finally the rotation angle was calculated by Equation (5). Figure 8 presents the static response for HELM prototype 3, with and without external load.…”

“…Elastomers, which are used in different types of hydraulic muscles ( [1][2][3][4][5]) as well as the HELM, typically exhibit loss of energy in a cycle of tension and release, in a phenomenon named hysteresis. When the hydraulic muscle is designed to do work efficiently, it is essential to minimize the energy losses.…”

“…Many variants of PAMs are shown along with analysis of response and actuation force and, along with some applications in prosthetics and robotics. Newer pneumatic actuators such as the Double-Acting sleeve muscle [5] show improvements over traditional muscles such as greater force capacity, lower energy consumption and bi-directional force application.…”

Novel Additive Manufacturing Pneumatic Actuators and Mechanisms for Food Handling Grippers

“…The major drawbacks for their use as actuators in robot grippers for food handling are their nonlinear behavior, the presence of hysteresis, their slow dynamics, and they can only work as contractive [20]. Some advances can be found to achieve double acting by embedding a muscle inside an external chamber [21].…”