空间机械臂系统轨迹规划仿真分析

Numerical simulation of trajectory planning for space manipulator

在轨组装系统处于空间微重力环境下,其机械臂的动力学模型有别于地面环境下的。文章以空间三自由度机械臂为研究对象,采用适用于空间环境的拉格朗日方程,推导机械臂系统的动力学方程,仿真得到不同作用力矩下各关节的动力学响应,分析并校验动力学模型的准确性。仿真结果表明:所建动力学模型准确可靠,与实际相符,且直观表述了各个转角间因关节力矩不同所产生的相互耦合情况。文章还在常规的机械臂轨迹规划方法基础上,提出一种新的轨迹逼近策略,并对比两种不同轨迹逼近策略的优劣,证明本文方法在效率和精度上更优,且可确保按照期望的路径执行空间环境下的目标捕捉任务。

In the weightlessness environment of the space,the dynamic model of the space manipulator for the on-orbit assembly system is different from that under the ground condition.In this paper,with the spatial 3-DOF manipulator as the subject,the dynamic equation is derived by using the Lagrange equation tailored to the space environment.The dynamic response of each joint is obtained by the simulation of different critical moments,and the accuracy of the dynamic model is verified by the simulation results.The coupling of different rotation angles due to different joint torques is clearly shown.At the same time,a new trajectory approximation strategy is developed on the basis of the traditional path planning method.Comparison of the two methods shows that the point-to-point approximation method enjoys a better precision and a higher efficiency,allowing the engineering task to be carried out according to the desired path in the space environment.The above studies can also be used for the design of the space manipulator system.