A time-optimal motion planning method for robotic machining of sculptured surfaces is reported in this paper. Compared with the general time-optimal robot motion planning, a surface machining process provides extra constraints such as tool-tip kinematic limits and complexity of the curved tool path that also need to be taken into account. In the proposed method, joint space and tool-tip kinematic constraints are considered. As there are high requirements for tool path following accuracy, an efficient numerical integration method based on the Pontryagin maximum principle is adopted as the solver for the time-optimal tool motion planning problem in robotic machining. Nonetheless, coupled and multi-dimensional constraints make it difficult to solve the problem by numerical integration directly. Therefore, a new method is provided to simplify the constraints in this work. The algorithm is implemented on the ROS (robot operating system) platform. The geometry tool path is generated by the CAM software firstly. And then the whole machine moving process, i.e. the feedrate of machining process, is scheduled by the proposed method. As a case study, a sculptured surface is machined by the developed method with a 6-DOF robot driven by the ROS controller. The experimental results validate the developed algorithm and reveal its advantages over other conventional motion planning algorithms for robotic machining.

本文报道了一种用于机器人加工雕刻表面的时间最优运动计划方法。与一般的最佳时间机器人运动计划相比，表面加工过程提供了额外的约束条件，例如刀尖运动极限和弯曲刀具路径的复杂性，这些也需要考虑在内。在提出的方法中，考虑了关节空间和工具提示运动学约束。由于对刀具路径跟随精度有很高的要求，因此采用基于Pontryagin极大值原理的有效数值积分方法作为机器人加工中时间最优的刀具运动计划问题的求解器。但是，耦合和多维约束使直接通过数值积分解决问题变得困难。因此，提供了一种新方法来简化这项工作中的约束。该算法在ROS（机器人操作系统）平台上实现。几何刀具路径首先由CAM软件生成。然后通过提出的方法来调度整个机器的移动过程，即加工过程的进给率。作为案例研究，使用由ROS控制器驱动的6自由度机器人通过开发的方法加工雕刻的表面。实验结果验证了所开发的算法，并显示了其相对于其他传统的机械加工运动计划算法的优势。通过建议的方法进行调度。作为案例研究，使用由ROS控制器驱动的6自由度机器人通过开发的方法加工雕刻的表面。实验结果验证了所开发的算法，并显示了其相对于其他传统的机械加工运动计划算法的优势。通过建议的方法进行调度。作为案例研究，使用由ROS控制器驱动的6自由度机器人通过开发的方法加工雕刻的表面。实验结果验证了所开发的算法，并揭示了其相对于其他传统的机器人加工运动计划算法的优势。