空间机器人路径规划综合优化方法

Multi-objectives Optimization Method for Path-planning of Space Robot

执行复杂操作的空间机器人常具有冗余自由度,从而可以在执行任务过程中通过关节参数的合理规划对指定目标进行优化。振动和操作灵活性是评价空间机器人性能和任务完成质量的两项重要指标,而关节力矩的大小是影响振动的重要因素。文章提出了一种路径规划综合优化方法,在对机器人末端运动速度进行优化处理的基础上,利用其冗余自由度,对关节力矩和评价操作灵活性的条件数指标进行综合优化。以平面3自由度机器人为对象建立数学模型,并在零重力环境下对相同任务进行数学仿真。仿真结果显示,采用文章优化方法,关节力矩与操作灵活性指标均得到了有效优化,验证了所提出方法的有效性。

Space robots for complicated missions are usually redundant, so they can finish mis- sions with different selection of joints parameters to fulfill different optimization objectives. Vibration and flexibility of movement are two important criteria for evaluating performance of space robots, and magnitude of joints torque is an important factor which can affect the vibration. For path-planning this paper proposes a method which can simultaneously optimize joints torque and condition number, based on the optimization of the velocity of robot end and by employing the redundant DOF （degree-of-freedom） of robot. A strategy for smoothing the velocity curve of end-effector is also employed in this method. A simulation study is conducted in this paper. In this study, the simulated subject is a planar 3-DOF robot in zero-gravity environment, a mathe- matical model is established and two results of the same mission with different path-planning are presented. By contrasting their results, effectiveness of the proposed method is proved, including the optimization of torque and condition number.