Kinematic and Dynamic Characteristics Analysis of Bennett’s Linkage

Changjian Zhi,Sanmin Wang,Yuantao Sun, Jianfeng Li

(School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China)



Abstract:

Bennett’s linkage is a spatial fourlink linkage, and has an extensive application prospect in the deployable linkages.Its kinematic and dynamic characteristics analysis has a great significance in its synthesis and application.According to the geometrical conditions of Bennett’s linkage,the motion equations are established,and the expressions of angular displacement, angular velocity and angular acceleration of the followers and the displacement, velocity and acceleration of mass center of link are shown. Based on Lagrange’s equation, the multi-rigid-body dynamic model of Bennett’s linkage is established. In order to solve the reaction forces and moments of joint, screw theory and reciprocal screw method are combined to establish the computing method.The number of equations and unknown reaction forces and moments of joint are equal through adding link deformation equations. The influence of the included angle of adjacent axes on Bennett’s linkage’s kinematic characteristics, the dynamic characteristics and the reaction forces and moments of joint are analyzed. Results show that the included angle of adjacent axes has a great effect on velocity, acceleration, the reaction forces and moments of Bennett’s linkage. The change of reaction forces and moments of joint are apparent near the singularity configuration.

Key words:  bennett’s linkage  kinematic characteristics  dynamic characteristics  Lagrange’s equations  screw theory  reciprocal screw method

DOI：10.11916/j.issn.1005-9113.2015.03.014

Clc Number:TH122

Fund: