Optimal Path Planning for Space Robots with Joint Friction Torque.
Optimal Path Planning for Space Robots with Joint Friction Torque.
复制标题
具有关节摩擦力矩的空间机器人的最优路径规划。
DOI：
10.1299/kikaic.64.1368
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
N. Komatsu
中科院分区：
文献类型：
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作者：
H. Okubo;Kiyoshi Kobayashi;N. Komatsu
提出了一种空间机器人最优路径规划方法，以实现机械手手部最终位置所需的总力矩最小。所提出的方法确定了关节角的最佳轨迹，使应用在关节执行器上的输出扭矩总量最小。本文将关节作动机构固有的非线性摩擦力矩以及机械手运动所使用的动态力矩用运动方程建模。利用轨迹的傅立叶级数逼近解决了最优控制问题。从而将原来的最优控制问题简化为非线性参数优化问题，并采用Rosenbrock方法进行代价函数的最小化。序列共轭梯度与恢复（SCGR）算法也被用于改进傅里叶级数解。对具有三连杆刚性机械臂的自由飞行空间机器人的二维实验模型进行了数值模拟。结果表明，得到的最优轨迹高度依赖于关节摩擦力矩的大小，这意味着关节摩擦力矩的精确建模对于最优路径规划非常重要。
This paper presents a method of optimal path planning for space robots to minimize the total accouter torque required for realizing the final position of the manipulator hand. The proposed method determines the optimum trajectory of joint angles that minimizes the total amount of the output torque to be applied at the joint actuators. In this paper, the nonlinear friction torque inherent to the joint actuator mechanism, as well as the dynamic torque used for the manipulator motion, is modeled in the equations of motion. The optimal control problem is solved by using Fourier series approximation of the trajectories. Thereby the original optimal control problem is reduced to a nonlinear parameter optimization problem, where the Rosenbrock method is used in the cost function minimization. The sequential conjugate gradient and restoration (SCGR) algorithm is also used for improving the Fourier series solutions. Numerical simulations are made for a twodimensional experimental model of free-flying space robot having a three-link rigid manipulator. The results show that the obtained optimum trajectory depends highly on the magnitude of the joint friction torque, which imply the fact that an accurate modeling of the joint friction torque is very important for the optimal path planning.