气动齿状软体驱动器的理论建模、仿真分析及实验研究

Theoretical Modeling,Simulation Analysis,and Experimental Investigation of a Pneumatic Toothed Soft Actuator

针对气动齿状软体驱动器,从腔室侧壁膨胀角和驱动器弯曲角度的非线性几何关系出发,基于虚功原理和Neo-Hookean超弹性不可压缩材料的非线性本构关系,建立了同时考虑底层、侧壁、前后壁应变能的准静态力学模型.该模型考虑了几何非线性和材料非线性,能够准确高效求解不同驱动气压和末端载荷作用下的软体驱动器构型.在此基础上利用Abaqus软件对固支-自由软体驱动器进行有限元仿真,并搭建了相应的实验装置,对不同气压作用下的驱动器进行了仿真分析和实验研究.结果表明:驱动气压与软体驱动器的弯曲角度呈线性相关,且理论模型的预测结果与有限元仿真和实验结果基本吻合.此外,分析了软体驱动器各部位的应变能分布情况.针对驱动器受末端载荷的变曲率情况,基于分段等曲率模型得到的构型与Abaqus基本一致.该准静态建模方法为同类软体驱动器的结构优化设计、性能改善和运动控制建立理论基础.

Based on the nonlinear geometric relationship of the bulging angle and the bending angle,and the principle of virtual work and nonlinear constitutive relationship of Neo-Hookean incompressible hyperelastic material,a quasi-static mechanical model for pneumatic toothed soft actuator was established,considering the strain energy of the bottom,side walls,and front and rear walls.Considering the geometric nonlinearity and material nonlinearity,the proposed model could solve the configuration of the soft actuator at different driving pressures and terminal loads precisely and efficiently.The finite element simulation of the cantilevered-free soft actuator was conducted by Abaqus,and the corresponding experimental device was established.The simulation analysis and experimental investigation were performed at different driving pressures.A comparison of the results show that there is a positive linear correlation between the driving pressure and the bending angle of the soft actuator,and the prediction of the theoretical model agrees well with the simulation and experimental results.In addition,the distribution of the strain energy was analyzed.Based on the equal-curvature model,the configuration results of the soft actuator at terminal loads are basically consistent with those obtained by Abaqus.The proposed quasi-static mechanical modeling method provides a theoretical basis for the structural optimization design,performance improvement,and motion control of similar soft actuators.