装煤是采煤机螺旋滚筒叶片的主要功能，复杂煤层赋存条件和非线性冲击载荷会使其磨损加剧甚至失效，尤其的叶片的尾端和外缘部分，运用激光熔覆再制造的方法对磨损的叶片进行修复，可以提高其使用寿命。针对激光熔覆实验中机械臂的路径轨迹，运用Matlab Robotics Toolbox建立机器人改进DH模型，用蒙特卡洛方法得到其工作空间点云图，用alphaShape()函数对点云进行包络处理，求解出工作空间的体积为27.021 7 m3，验证了改进DH建模的正确性，能满足对采煤机螺旋叶片激光熔覆的任务要求。对熔覆实验中机械臂的轨迹进行仿真分析，为叶片的激光熔覆实验做准备。应用运动学分析软件Admas模拟机械臂对叶片外缘螺旋曲线的增材过程，得出其各关节的运动学参数和驱动电机所需的转矩。在重力和末端负载的作用下，运动轨迹的突变使法兰盘出现数量级为10-10的微小波动。将关节角时间序列导入SimMechanics中，作为驱动能控制机械臂做相同的螺旋曲线运动，验证了Adams中得到的关节角时间序列的驱动具有实际意义。对磨损最为严重的尾片磨损曲面特征进行分析，并划分为区域A，B，C。用KUKA机器人示教器在线编程，以直线增量蛇形往复方式,在叶片区域A熔覆耐磨层，改变激光头的姿态使其垂直于叶片的磨损曲面，在区域C熔覆样条曲线，用三维扫描仪获取区域B的点云，并重构曲面。将磨损模型与完整叶片模型利用布尔运算(剪切)得到待熔覆区域的STL文件，并导入增材制造辅助编程软件生成路径程序，熔覆实验时间为70 min，机器人运动平稳，且成型质量良好，几何特征与原叶片一致。研究方法为螺旋叶片修复和其他复杂曲面零件的再制造提供了参考，有较好的工程应用价值。

The main function of shearer drum spiral blade is to load coal.The complex occurrence conditions of coal seam and nonlinear impact load will result in blade wear and even failure,especially for its tail end and outer edge.Using a laser cladding and remanufacturing method to repair the worn blade can improve the service life of spiral blade.In terms of the path and trajectory of manipulator in the laser cladding experiment,the modified DH robot model was established by using Matlab Robotics Toolbox.Monte Carlo method was used to obtain the point cloud of robot working space,and then alphashape() function was used to envelop the point cloud.The volume of working space was 27.021 7 m3,which refected that the improved DH modeling was valid and could meet the task requirements from the laser cladding of shearer spiral blades.The trajectory of manipulator in the cladding experiment was simulated and analyzed to prepare for the laser cladding experiment of the blade.Using kinematic analysis software ADMAS,the process of laser cladding to the spiral curve of the outer edge of blade by manipulator was simulated.The kinematic parameter of each joint and the torque required to drive the motor were obtained.Under the influence of gravity and end load,the sudden change of motion track would make a relative displacement of joint 6 and the relative angular displacement in Y direction fluctuation in an order of magnitude of.The joint angle time series was imported into SimMechanics to act as the driving to control the manipulator to do the same spiral curve movement,which verified that the driving of the joint angle time series in Adams is of practical significance.The wear surface characteristics of tail blade with the most serious wear were analyzed,and divided into area A,B and C.Using KUKA robot online programming,the wear-resistant layer was cladded in the blade area A with the form of space linear incremental serpentine reciprocating path.Changing the laser head’s attitude perpendicular to the blade’s wear surface,the spline curve was cladded in area C.The point cloud of area B was acquired by 3D scanner,and the surface was reconstructed.The STL file of the area to be cladded was obtained by Boolean calculation (shearing) between wear model and complete blade model,and the path program was generated by the additive manufacturing auxiliary programming software.The experimental time of cladding was 70 min.The robot moved smoothly,and the forming quality was good,and the geometric characteristics were consistent with the original blade.The research method can provide a reference for the repair of shearer’s spiral drum and the remanufacturing of other complex surface,and has a good engineering application value.

1 对机器人的运动学分析

   1.1 基于改进DH法的机器人模型构建

   1.2 机器人的正运动和工作空间分析

   1.3 机器人的逆运动和末端轨迹规划

2 机器人末端螺旋曲线轨迹仿真分析

   2.1 基于Adams的螺旋曲线轨迹仿真分析

   2.2 基于SimMechanics螺旋曲线仿真分析

3 滚筒螺旋叶片的激光熔覆实验

4 结论