Recently, robot manipulators have been adopted to perform machining tasks, instead of only automation tasks. The key machining task is to follow a desired contour. Therefore, the machining accuracy can be improved by reducing contour error. However, only a few researches concentrate on solving the contouring problem in the robotic machining system. In this paper, a model predictive control (MPC)-based contouring control scheme is proposed for a machining system based on a 5-DOF dual-arm robot. The contouring control problem is transformed into the regulation problem by using the method of equivalent errors. An MPC algorithm is developed to minimize the contour error by optimizing a sequence of control actions under torque constraints. In addition, robustness is upgraded by integral sliding mode control (ISMC). Experiments are carried out for the proposed methods and two other conventional methods. The results show that the proposed control scheme can achieve much better contouring performance than the conventional methods, indicating the effectiveness of the proposed controller.

中文翻译：

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基于 MPC 的机器人加工系统鲁棒轮廓控制

最近，机器人机械手已被用于执行加工任务，而不仅仅是自动化任务。关键的加工任务是遵循所需的轮廓。因此，可以通过减少轮廓误差来提高加工精度。然而，只有少数研究专注于解决机器人加工系统中的轮廓问题。在本文中，提出了一种基于模型预测控制（MPC）的轮廓控制方案，用于基于 5 自由度双臂机器人的加工系统。利用等效误差的方法将轮廓控制问题转化为调节问题。开发了 MPC 算法，通过优化扭矩约束下的一系列控制动作来最小化轮廓误差。此外，通过积分滑模控制 (ISMC) 提升了鲁棒性。对所提出的方法和其他两种常规方法进行了实验。结果表明，所提出的控制方案可以实现比传统方法更好的轮廓性能，表明所提出的控制器的有效性。