偏置式空间RSSR急回仿生扑翼机构优化设计与分析

Optimal Design of RSSR Quick-return Bionic Flapping-wing Mechanism in Offset Space

本文基于偏置式空间RSSR四杆机构,设计了一种具有急回特性的扑翼机构,通过运动分析建立了空间RSSR四杆机构的运动学模型。以关节轴承处构件运动角和机构的压力角作为优化模型的非线性约束条件,摇杆摆角和行程比系数为目标函数建立了扑翼机构的优化设计模型。利用遗传算法对机构进行了优化计算,得到了利与飞行的相对杆长参数。基于优化得到的相对杆长参数以及鸟类飞行参数,选取曲柄长度为10 mm设计了一款仿生扑翼机构。结果表明:所设计的扑翼机构最小传动角y_(min)=40.01°,节轴承处构件运动角最大为60°,扑动上极限夹角ψ_(max)=21.92°,下极限夹角ψ_(min)=-18.11°,行程速比系数K=1.5与选取仿生鸟类飞行运动参数一致。

Based on the bias spatial RSSR four-bar mechanism,this paper designs a flapping wing mechanism with the characteristic of quick return,and establishes the kinematics model of the spatial RSSR four-bar mechanism through motion analysis.The optimal design model of the flapping wing mechanism is established by taking the motion angle and the pressure angle of the joint bearing as nonlinear constraints and the rocker swing angle and the stroke ratio coefficient as objective functions.Genetic algorithm is used to optimize the calculation of mechanism.Based on the relative rod length parameters of profit and flight obtained through optimization,a bionic flapping wing mechanism is designed with the crank length of 10 mm.The results show that the minimum transmission angle of the designed flapping wing mechanism,the maximum motion angle of the member at the joint bearing,the upper limit angle and the lower limit angle of flapping,and the travel speed ratio coefficient are consistent with the flight parameters of the bionic birds.