三自由度气动柔性驱动器结构功能与形变特性研究

Structure and Deformation Characteristics of 3-DOF Pneumatic Flexible Actuator

设计了一种采用伸长型气动人工肌肉的三自由度柔性驱动器,该驱动器的驱动装置与本体复合一体,主要由3根对称分布的人工肌肉并联组成。根据力和力矩分析,考虑了驱动器伸长量、弯曲方向和弯曲角度的综合影响,建立了驱动器伸长量、弯曲方向和弯曲角度的非线性理论模型。通过试验对理论模型进行了验证,获得了柔性驱动器在不同通气方式下的形变性能。结果表明:该柔性驱动器弯曲时近似圆弧状,具有较高灵活性,能够实现轴向伸长和空间内任意方向弯曲,可作为执行部件应用于农业机器人和果蔬采摘机械手等仿生机械上。

A type of 3-DOF flexible pneumatic actuator （FPA） employing elongation pneumatic artificial muscles was developed. It was mainly composed by three pneumatic artificial muscles symmetrically distributed in parallel and three artificial muscles were fixed 120° each other in space. The pneumatic artificial muscle was a closed cavity formed by the rubber tube and the end covers, and the outer side of it was thin sheet restraint rings set compacted. The elastic skeletons were added among the artificial muscles to improve the rigidity and stability of FPA. Specially, the driving device of FPA was just the body of the actuator. The FPA has the advantages of small volume, light weight and multiple degrees of freedom, and it can axially elongate and bend in any direction by controlling the input gas pressure of different artificial muscles. According to the force and torque analysis, the nonlinear theoretical model was developed to simultaneously describe the elongation, bending direction and bending angle of the FPA. Further, the theoretical model was verified by experiments, and then the deforming properties of FPA were obtained under different ventilation modes. The results showed that the FPA was in arc shape approximately when it was bent; it had high flexibility to elongate in axial direction or bend in any direction which had the similarity to the biological muscles in the body flexibility, movement and driving ability. In summary, this type of FPA can be as flexible fingers or flexible joints applied to fruit and vegetable picking manipulator or agrieuhural robot.