The Design and Mathematical Model of a Novel Variable Stiffness Extensor-Contractor Pneumatic Artificial Muscle

Abstract

This article presents the design of a novel extensor-contractor pneumatic artificial muscle (ECPAM). This new actuator has numerous advantages over traditional pneumatic artificial muscles. These include the abilities to both contract and extend relative to a nominal initial length, to generate both contraction and extension forces, and to vary stiffness at any actuator length. A kinematic analysis of the ECPAM is presented in this article. A new output force mathematical model has been developed for the ECPAM based on its kinematic analysis and the theory of energy conservation. The correlation between experimental results and the new mathematical model has been investigated and show good correlation. Numerous stiffness experiments have been conducted to validate the variable stiffness ability of the actuator at a series of specific fixed lengths. This has proven that actuator stiffness can be adjusted independently of actuator length. Finally, a stiffness-position controller has been developed to validate the effectiveness of the novel actuator.

Power-Efficient Soft Pneumatic Actuator Using Spring-Frame Collateral Compression Mechanism

“…The proposed SFCC mechanism stands out in improving all of the contraction force, actuation speed, and efficiency compared to the contractile soft actuators of previous studies [20,22,24]. In addition, compared to the previous studies of the improved McKibben-type actuators [21,29], we increased the contraction length and minimized the reduction of contraction force due to buckling of the inner part with the spring frame internal actuator. The proposed SFFC PAM simultaneously contracts both the external and internal actuators and exerts 31% higher actuation force than the conventional McKibben PAM.…”

Status of and trends in soft pneumatic robotics

“…而半主 动的拮抗作用则由主动的驱动器与被动的弹性或者刚 性的约束结构组成 [205] . 基于McKibben驱动器的"静水 骨骼"则可以视为半主动的拮抗机构, 其变刚度是由充 气膨胀的弹性气囊和限制膨胀的袖套结构形成的等容 变刚度结构来实现的 [206,207] , 如图18(a). [96] ; (b) 凯夫拉短纤维增强硅胶基体的自愈合气动软体驱 动器 [195] ; (c) 内嵌光敏树脂的自修复软体驱动器 [198] Figure 17 (Color online) Self-healing/sealing soft pneumatic actuators based on different principles.…”

Novel Design and Modeling of a Soft Pneumatic Actuator Based on Antagonism Mechanism

“…This output force model is suitable for that considering friction, soft actuators with internal and external muscle composite structures, and the output force can be predicted based on the input pressure and posture accurately. Compared to previous studies on soft actuators [22,23], they did not take friction into account.…”