基于渐开线轮廓凸轮的杠杆式偏角解耦变刚度关节设计

Design of a Lever-type Deflection Angle Decoupling Variable-stiffness Joint Based on Involute Contoured Cam

针对当前的杠杆式变刚度关节存在的刚度与偏角耦合的缺点,提出一种变刚度关节设计方案。首先,提出了可调支点杠杆机构的结构方案。通过静力学模型分析得出关节刚度与偏角无关。进而,设计了调整杠杆机构支点位置的渐开线凸轮机构,使得凸轮转角与支点位置成线性关系,降低了关节刚度调节的难度。最后,设计并制作了变刚度关节的原理样机,分别进行了样机关节刚度特性以及刚度与偏角关系的仿真与实验,验证了变刚度原理的可行性以及刚度与偏角的解耦性。

Current lever-type variable-stiffness joints suffer from the coupling between stiffness and deflection angle.To overcome this limitation,a variable-stiffness joint design scheme is proposed.Firstly,a structure scheme of the adjustablepivot lever mechanism is proposed.Herein,the joint stiffness is proved to be independent of deflection angle by analyzing the statics model.Furthermore,an involute cam mechanism is designed to adjust the pivot position of the lever mechanism,achieving a linear relationship between the cam angle and the pivot position.This design reduces the difficulty in adjusting the joint stiffness.Finally,a prototype of variable-stiffness joint is designed and manufactured,and the stiffness characteristics of the prototype joint and the relationship between stiffness and deflection angle are simulated and tested respectively.The feasibility of the variable-stiffness principle and the decoupling between stiffness and deflection angle are verified.