受重力梯度扰动的空间机器人姿态动力学非线性特征分析

研究考虑重力梯度扰动的自由漂浮空间机器人姿态动力学建模方法.以二连杆空间机器人模型为基础,对机械臂构型固定时系统俯仰姿态受扰运动的非线性特征进行了深入分析.利用相平面轨迹和Poincaré截面对受扰运动特征进行了描述,反映出受扰运动对轨道偏心率的变化比较敏感,在圆轨道时仅有周期摆动和翻滚两种形式,而在椭圆轨道时出现了准周期运动.进一步利用系统分岔图、功率谱图对这种非线性运动特征进行了定量分析.

Nonlinearity of the attitude motion of space robots subjected to gravitational gradient torque

The attitude dynamics equation of free-floating space robots subjected to gravitational gradient effect is investigated. A two-link space robot is employed to analyze nonlinear properties of the perturbed yaw motion of the system in depth, when the manipulator configuration is fixed. Its nonlinear dynamical behavior is described by phase plane plot and Poincaré section. It is shown that the perturbed motion is sensitive to orbital eccentricity. The system takes on periodic motion and tumbling in circular orbit, while additional quasi-periodic motion in elliptic orbit. Furthermore, these nonlinearities are quantitatively studied by means of bifurcation and power spectrum.
Keywords： gravitational gradient space robots attitude dynamics nonlinearity