In this article, an optimization method is proposed for the dimensional synthesis of robotic manipulators with limited mobility, i.e. with less than 6 degrees-of-freedom (“DoF”), with a prescribed set of tasks in a constrained environment. Since these manipulators cannot achieve full 6-DoF mobility, they are able to follow only certain paths with prescribed position and orientation in space. While the most common approach to this problem employs pure path-planning algorithms, operations in narrow and complex environments might require changes to the robot design too. For this reason, this paper presents an improved approach which aims to minimize position and orientation error with a dimensional synthesis. First, a novel methodology that combines a path planning algorithm and dimensional synthesis has been proposed in order to optimize both robot geometry and pose for a given set of points. Then, the method is validated with a 4-DoF robot for high-precision laser operations in aeroengines as a case study. The example shows that the proposed procedure provides a stable algorithm with a high convergence rate and a short time to solution for robots with limited mobility in highly constrained scenarios.

在本文中，提出了一种用于运动受限的机械手的尺寸合成的优化方法，即具有小于6个自由度（“ DoF”），在受限环境中具有规定任务的机器人。由于这些操纵器无法实现完整的6自由度移动性，因此它们只能遵循在空间中具有规定位置和方向的某些路径。解决此问题的最常用方法是使用纯路径规划算法，但在狭窄和复杂环境中的操作可能也需要更改机器人设计。因此，本文提出了一种改进的方法，该方法旨在通过尺寸综合来最大程度地减少位置和方向误差。第一，为了优化给定点集的机器人几何形状和姿势，提出了一种结合了路径规划算法和尺寸合成的新颖方法。然后，作为案例研究，使用4-DoF机器人对该方法进行了验证，该机器人可用于航空发动机中的高精度激光操作。实例表明，所提出的程序为高受限场景下行动受限的机器人提供了一种收敛速度快，求解时间短的稳定算法。