基于粒子沉积与传热机理的等离子喷涂机器人轨迹优化研究

Air Plasma Spray (APS) technique is a complex coating process for depositing the appropriate surface protection by accumulation of heated particles, and the resulting coatings are influenced by various factors. The requirement of high performance coatings on the complex free-form surface leads to challenges in the field of APS for efficient trajectory generation algorithm and optimized spray parameters are demanded. This research concerns on the parametric model of deposition distribution of particles, and a model of deposition rate is thus established to obtain a feasible solution to optimization problems. By analyzing the topology structure, a slicing algorithm is presented to decompose the free-form surface into several small pieces of simple topological type. The following research is to determine a proper initial curve that can not only minimize the total length of subsequent offset curves but also ensure the distance consistency among offset curves. The research also creatively puts forward a novel research approach to introduce the heat transfer analysis into the trajectory planning process. Combining heat transfer analysis with trajectory planning overcomes the defects of traditional trajectory planning methods (e.g., local over-heating) which helps form the uniform temperature field through optimizing the time sequence of path curves. The pieces optimal arrangement is translated into Traveling Salesman Problem(TSP) firstly, and then an improved intelligent algorithm is used in this work to solve the TSP. The presented approach in this research helps obtain the shortest complete coverage trajectory, to achieve both the coating thickness, uniformity prediction and the uniform temperature field, and it also provides a new study method for APS robot trajectory planning research.

大气等离子喷涂涉及到热、相变等复杂的物理化学过程，制备阶段影响因素众多。如何选择合理的工艺参数，通过等离子喷涂机器人轨迹规划生成复杂自由曲面上满足精度要求的覆盖涂层，是该领域内亟待解决的问题，也是本项目研究的主要内容。本项目通过参数化描述等离子体射流中粒子的沉积特性，推导等离子涂层生长过程数学模型，获取喷涂参数有效解。基于复杂自由曲面拓扑结构研究分片算法，将其分解成多个拓扑简单的局部区域。根据测地线原理研究局部区域路径曲线生成方法，求解最短且能保持间距一致性的机器人路径曲线。创造性地提出将等离子喷涂传热分析引入到机器人轨迹规划中，优化各路径曲线执行的时间序列，均匀化温度场。利用智能算法求解各局部路径的排列问题，实现喷涂轨迹的全局优化。通过本项目的研究工作，预期生成最短且能覆盖整个喷涂区域的优化轨迹，实现喷涂后涂层厚度、均匀度预测，形成均匀温度场，为等离子喷涂机器人轨迹规划提供新的研究方法。

大气等离子喷涂涉及到热、相变等复杂的物理化学过程，制备阶段影响因素众多。通过选择合理工艺参数，进行等离子喷涂机器人轨迹规划生成复杂自由曲面上满足精度要求的全覆盖涂层，是该领域内亟待解决的问题，也是本项目研究的主要内容。.本项目的研究工作主要体现在以下几个方面：.1.通过参数化描述等离子体射流中粒子的沉积特性，推导等离子涂层生长过程数学模型，获取喷涂距离、路径间距、扫掠速度等参数的有效解。.2.基于曲率一致性对复杂自由曲面拓扑结构进行聚类分片，将其分解成多个拓扑简单的局部区域。根据测地线原理研究局部区域路径曲线生成方法，求解最短且能保持间距一致性的机器人路径曲线。.3.提出将等离子喷涂传热分析引入到机器人轨迹规划中，优化各路径曲线执行的时间序列，均匀化温度场，求解最优路径拓扑结构。.4.利用蚁群算法求解各局部路径的排列问题，实现喷涂轨迹的全局优化。.通过本项目的研究工作，能够生成最短且能覆盖整个喷涂区域的优化轨迹，实现喷涂后涂层厚度、均匀度预测，形成均匀温度场，为等离子喷涂机器人轨迹规划提供新的研究方法。