Pneu-net型变曲率软体驱动器弯曲性能与控制的研究

Research on the bending performance and control of a variable curvature Pneu-net soft actuator

气动软体驱动器是气动软体机器人的基础和关键元件,在实现软体机器人弯曲运动方面有着无可比拟的优势。但是气动软体驱动器在结构和材料方面都存在明显的非线性,这对软体驱动器的建模和精确控制提出了很大的挑战。本文基于分段常曲率变形假设、Yeoh超弹性材料本构模型和虚功原理建立了pneumatic networks (pneu-net)型常曲率软体驱动器的弯曲数学模型,通过有限元仿真研究了结构参数和输入气压对驱动器弯曲性能的影响。在此基础上提出了变参数变曲率驱动器设计,建立了其弯曲变形预测模型,并进行了多驱动器一致性误差分析,有限元仿真和实验验证了模型的有效性。最后对软体驱动器的力输出特性进行了实验测试,制作了一个三指软体抓手,通过实验展示了软体抓手抓持不同物体的性能。

Pneumatic soft actuators are fundamental and critical components of pneumatic soft robot,offering unparalleled advantages in achieving bending motions.However,the nonlinearity of both structure and material property presents great challenge for modeling and control of soft actuators.Based on the assumption of piecewise constant curvature deformation,Yeoh hyperelastic material constitutive model,and the virtual work principle,a bending model of a pneumatic networks(pneu-net)soft actuator with constant curvature is established in this paper.Finite element simulations were conducted to investigate the effects of structural parameters and input air pressure on the bending performance of the actuator.On this basis,a variable parameter variable curvature actuator design was proposed,and a predictive model for its bending deformation was established.Consistency error analysis for multiple actuators was performed,and the model′s validity was verified through finite element simulations and experiments.Finally,the force output characteristics of the soft actuators were experimentally tested.A three-finger soft gripper was developed,and the performance of gripping different objects was shown by experiments.