空间对接中差动式缓冲阻尼机构的建模研究

A Study on Kinematics and Dynamics Modeling of Differential Damping Mechanism in Space Docking

以美俄在ＡＳＴＰ计划中“联盟号”飞船的对接机构为背景，首先研究了差动式机电缓冲阻尼系统的结构组成和运动原理，并且建立了由捕获环、传动丝杠和固定机架组成的六自由度并联多环机构的运动简化模型。然后运用运动影响系数（ＫＩＣ）方法，通过对位形函数直接求导，得到系统的一、二阶运动影响系数矩阵，从而描述了机构各部件的运动关系；在运动学模型的基础上，重点分析了对接过程中该缓冲阻尼机构主要运动部件的动能，与丝杠、差速器相连的弹簧机构的势能，以及考虑耗散力为速度的线性函数时，电磁制动器和摩擦制动器的瑞利耗散函数，并采用拉格朗日第二类方程建立了系统运动微分方程，从而得到了系统动力学模型。最后给出了差动式机电缓冲阻尼系统在一般工况下工程实用的刚度和阻尼系数简化模型。

Concerning the peripheral docking system of Russian Soyuz spacecraft in ASTP,the paper first studies the structure and basic motion relations of the differential damping mechanism and builds a simplified motion model.Then,by using Kinematics Influence Coefficients(KIC) method,the first and second order of Kinematics Influence Coefficients matrix which can describe each part motion are given.On the basis of kinematics modeling,it discusses the kinetic energy of transmission parts in the differential mechanism,the potential energy of springs connecting with screw rods or gear differential units,and the Rayleigh dissipative function of electromagnetical dampers and friction damper while the dissipative force is considered as being linear with velocity.By means of the Second Lagrange Equation,the mechanism movement differential equations are given and gets the mechanism dynamics modeling is got.Finally the expression of system stiffness coefficient and system damping coefficient in arbitrary docking mode are reached.