改进型Delta 并联机构连续刚度映射.PDF

第33卷第10期 东 北 大 学 学 报 ( 自 然 科 学 版 ) Vol. 33, No. 10 2 0 12 年 10 月 Journal of Northeastern U ni ersity( Natural Science) O ct. 2 0 1 2 Delta 徐东涛, 孙志礼 ( , 110819) : Hessian , Delta , , , , , Delta : ; Delta ; ; ; : TP 242. 2; TH 122 : A : 1005-3026( 20 12) 10- 1465-05 Continuous Stiffness Mapping of Modified Delta Parallel Mechanism X U Dong-tao, S UN Zhi-li ( School of Mechanical Engineering Automation, Northeastern Uni ersity, Shenyang 110819, China. Corresponding author : XU Dong-tao, E-mail: xudongtao @ sohu. com) Abstract: The stiffness matrix of a mechanism w as defined on the basis of the Hessian matrix of its potential energy, and a new continuous stiffness mapping model of the modified Delta mechanism w as established. Different from the traditional models, the proposed model takes into account the influences of not only stiffness of the acti e/ passi e hinge and gra ities factors on the mechanism stiffness, but also the change of the mechanism configuration and all parts elastic deformation under the constraint force. It is thus more general and exact than any other stiffness models. Finally, the characteristic index used to estimate the mechanism stiffness w as defined by combining the Rayleigh quotient of the stiffness matrix. T he stiffness characteristics w ere analyzed and discussed according to the distribution of stiffness index at both different positions in the w orkspace and different applied forces. Key words: parallel mechanism ; modified Delta mechanism; stiffness mapping; law of conser ation of energy ; stiffness characteristics [ 1] Delta Cla el 1988 , 3