空间机器人抓取未知目标的质量特性参数辨识

根据动量守恒定理，研究了单臂自由飘浮空间机器人抓取未知目标的质量特性参数辨识问题。已有文献中基于动量守恒原理进行的参数辨识只适用于系统线动量和角动量为零的情况，当两者不为零时无法得到正确的辨识结果。为解决此问题，本文首先在惯性系而非本体系下推导得到了机械臂抓取未知目标后的系统线动量和角动量，保证了其各分量的守恒特性。然后基于此特性，通过在轨测量两个时刻机器人本体的线速度、角速度以及机械臂各关节的角速度和转角信息，建立了含有未知目标质量特性参数的动量增量方程。最后根据三组测量信息，从联立的动量增量方程组中求解得到未知目标的质量特性参数。数值仿真表明，此方法在系统线动量和角动量为零和不为零两种情况下都能实现高精度的参数辨识，同时还避免了方程求解的奇异问题。

Inertial Parameter Identification of Unknown Object Captured by a Space Robot

Inertial parameter identification of unknown object captured by a manipulator on a free\|floating space robot is studied based on the conservation principle of linear and angular momenta. The momentum\|based identification in all the published work is proposed under the assumption that the linear and angular momenta of the whole system are zero, which means the parameters can not be identified when the momenta are actually not zero. In order to resolve this problem , firstly the linear and angular momenta are expressed in the inertial frame rather than in the base body\|fixed frame, so that the conservation of components of momenta is ensured. Then, by eliminating the linear and angular momenta from the momentum equations, the momentum increment equations are obtained and the inertial parameters of grasped object become the only unknown. Finally, by using three sets of measurements, the unknown inertial parameters are determined from the combined momentum increment equations. The simulation results demonstrate that the inertial parameters can be accurately identified by using this method in both cases of zero and nonzero momenta, and the problem of singular solution can also be avoided.