机器人激光除漆系统的设计与实现

Design and implementation of a robotic laser paint removal system

摘要:

为解决传统采用化学清洗、机械打磨和喷砂的除漆方法存在产生有害废弃物、损伤基底材料、效率低及劳动强度大等问题,基于飞机的结构形状及除漆要求,开发了一套用于飞机表面的机器人激光除漆系统,该机器人激光除漆系统由全向移动单元、四自由度机械臂单元、激光清洗单元和测控单元组成。首先根据DR-5无人侦察机的外形对激光除漆机器人进行了机械本体和控制架构设计,并采用D-H法对机械臂进行了运动学分析和工作空间分析,验证了机械臂的可达性；接着对该机械臂进行了重复性测试,其中Z向重复度利用激光位移传感器定量评价,X、Y向重复度采用误差圆评价；最后基于弓字形路径对DR-5无人侦察机机身的部分平面及曲面开展了激光除漆实验,并根据激光除漆后表面漆层残余厚度对除漆效果进行了评价。研究结果表明,激光除漆机器人的Z向重复度为0.039 mm,X、Y向重复度小于±2.000 mm；机身平面除漆实验残余厚度平均值为6.5 μm,曲面除漆实验残余厚度平均值为21.3 μm。

Abstract:

Traditional chemical cleaning, mechanical sanding, and sandblasting can produce large volumes of hazardous waste and damage the substrate. In addition, the depainting process is low-efficient and labor-intensive. Based on the aircrafts structural shape and paint removal requirements, a robotic laser paint removal system for aircraft maintenance is developed. The robotic laser paint removal system contains the omnidirectional moving unit, the four-degree-of-freedom robot arm unit, the laser cleaning unit, and the measurement and control unit. Firstly, the mechanical structure and control architecture of the laser paint removal robot are designed, based on the shape of the DR-5 unmanned aerial vehicle (UAV), and the robot arms kinematic analysis. Workspace analysis is carried out using the D-H method to verify the reachability of the robot arm. Secondly, the robot arm is tested for repeatability, where the Z-direction repeatability is quantitatively evaluated using laser displacement sensors, and the X andY-direction repeatability is evaluated using an error circle. Finally, based on the bow path, the laser paint removal test is carried out on part of the flat surface and the curved surface of the UAV fuselage. Moreover, the paint removal result is evaluated according to the residual thickness of the surface paint layer. The results show that the repeatability of the laser paint removal robot is 0.039 mm in Z-direction and less than ±2.000 mm in the X and Y-directions; the average residual thickness of the flat surface paint removal experiment is 6.5 μm and the average residual thickness of the curved surface paint removal experiment is 21.3 μm.