Lower path accuracy is an obstacle to the application of industrial robots in intelligent and precision grinding complex surfaces. This paper proposes a novel path accuracy enhancement strategy and different evaluation methods for a six-degree-of-freedom industrial robot FANUC M710ic/50 used for grinding an aero-engine blade. Six groups of theoretical tool paths individually planned on this complex surface were obtained using the iso-parametric method and the constant chord height method. Then the actual paths of the robot were dynamically recorded by a laser tracker with a high frequency. A revised Levenberg-Marquardt and Differential Evolution hybrid algorithm was proposed to improve the absolute robotic positioning accuracy by considering the average curvature variation rate, the arc length and the number of cutter contact points on planning paths. The results showed that the maximum positioning error had been drastically reduced from 0.792 mm to 0.027 mm. Based on the redefinition of robotic path accuracy, including position accuracy and shape accuracy in this work, the methods MP-TLD, BP-TPD and MP-TID were proposed to evaluate the enhanced path accuracy. The evaluation results showed that the different path planning methods have almost little effect on path accuracy. Furthermore, the maximum path deviation evaluated by the MP-TLD method was reduced from 0.378 mm to 0.044 mm, evaluated by the BP-TPD method was reduced from 0.374 mm to 0.029 mm, and evaluated by the MP-TID method was reduced from 0.205 mm to 0.026 mm. It is concluded that these evaluation methods are basically valid and the average path accuracy value is about 0.035 mm, for present complex surface grinding with this typical industrial robot. Finally, the robotic grinding experiments of titanium alloy blades are conducted to further validate the effectiveness of the proposed method.

较低的路径精度阻碍了工业机器人在复杂曲面智能化、精密磨削中的应用。本文针对用于磨削航空发动机叶片的六自由度工业机器人 FANUC M710ic/50 提出了一种新的路径精度增强策略和不同的评估方法。利用等参数法和等弦高法获得了在该复杂曲面上单独规划的六组理论刀具路径。然后机器人的实际路径由高频激光跟踪器动态记录。提出了一种改进的 Levenberg-Marquardt 和差分进化混合算法，通过考虑平均曲率变化率来提高绝对机器人定位精度，弧长和规划路径上刀具接触点的数量。结果表明，最大定位误差已从 0.792 毫米大幅降低至 0.027 毫米。基于机器人路径精度的重新定义，包括在这项工作中的位置精度和形状精度，提出了 MP-TLD、BP-TPD 和 MP-TID 方法来评估增强的路径精度。评估结果表明，不同的路径规划方法对路径精度的影响几乎没有。此外，MP-TLD法评估的最大路径偏差从0.378mm减少到0.044mm，BP-TPD法评估的最大路径偏差从0.374mm减少到0.029mm，MP-TID法评估的最大路径偏差从0.205减少毫米至 0.026 毫米。得出的结论是，这些评价方法基本有效，平均路径精度值约为0.035 mm，适用于目前典型工业机器人的复杂平面磨削。最后，进行了钛合金叶片的机器人磨削实验，进一步验证了所提方法的有效性。