双并联机构耦合连续体机械臂的设计与实现

Design and Realization of Continuum Manipulator Based on Coupling of Double Parallel Mechanism

设计并实现了具有5个定位自由度的连续体机械臂,以提高连续体机构在诸如腔内作业、轻物品抓取、人机协作等场景中的灵活定位能力.设计中,引入了二段定曲率模型,用旋量方法从几何上解释了该设计的自由度分配.两段可伸缩式并联机构的串联耦合,形成二段弯曲结构,其每一段有两个方向的弯曲自由度和一个伸缩自由度,从而组合出末端的5个自由度.围绕手臂的高动态性能,制作了样机的机电运动系统.实验结果表明,样机实现了连续体机械臂末端的自由度控制,可在2 s内到达极限姿态,其定位精度约为臂长的2%.

A 5-degree-of-freedom continuum manipulator is designed and implemented to improve the flexible positioning ability of the continuum mechanism in applications such as interactivity operations,light object grabbing,and human-machine collaboration.In the design process,by introducing a two-segment constant curvature model,the distribution of degrees of freedom on the mechanism is explained geometrically by the method of twist.Coupling two stretchable parallel modules in series,a two-segment structure is formed for curving and each segment has two degrees of freedom in bending and one degree of freedom in stretching,thereby giving 5 degrees of freedom to the end-effector.Concentrating on the dynamic performance of the manipulator,an electromechanical system platform is built as a prototype.The experiments show that the structure realizes the control of the end-effector during large deformation of the manipulator,and is able to achieve extreme pose in 2 s with an approximation positioning error of 2%of the nominal arm length.