Five-axis continuous scanning inspection is an emerging technology in measuring free-form surfaces. Compared to the traditional three-axis scanning inspection, the five-axis continuous surface scanning tremendously boosts the inspection efficiency and suffers from less dynamic error due to adopting a special sweep scanning working mode, which lets the super-light and high-speed rotary two-axis probe head take over the majority of the inspection work. However, there has not been any efficient method to generate sweep scanning path for a free-form surface with external obstacle. The major problem is how to guarantee the non-interference condition during the scanning process. In this paper, a two-step algorithm for generating smooth and interference-free sweep scanning path is proposed. First, an image-based algorithm is proposed to incrementally calculate the admissible area of the stylus along the scanning path. Then an optimized B-spline fitting algorithm is proposed to find the optimal probe head trajectory within the admissible area, which simultaneously guarantees the smoothness and non-interference of the trajectory. In the real experiment, the average tangential velocity and acceleration of the machine's translational axes with the proposed five-axis sweep scanning path are only 16.45% and 17.19% of those with three-axis zigzag scanning path respectively. When inspecting a high-accuracy cylindrical surface with high scanning velocity, the root mean square of the surface profile error is 0.002 mm and 0.004 mm in five-axis scanning and three-axis scanning respectively. The experimental result manifests that the sweep scanning path tremendously helps to reduce the kinematic loads and the dynamic errors of the inspection machine.

五轴连续扫描检查是测量自由曲面的新兴技术。与传统的三轴扫描检查相比，五轴连续表面扫描极大地提高了检查效率，并且由于采用了特殊的扫掠扫描工作模式，因此动态误差较小，这使得超轻和高速旋转两种轴探头负责大部分检查工作。但是，还没有任何有效的方法可以为带有外部障碍物的自由形式的表面生成扫掠扫描路径。主要问题是如何保证扫描过程中的无干扰条件。本文提出了一种生成平滑且无干扰的扫描路径的两步算法。第一的，提出了一种基于图像的算法，以沿扫描路径递增地计算触控笔的允许区域。然后提出了一种优化的B样条拟合算法，以在允许的区域内找到最优的探头轨迹，同时保证了轨迹的平滑性和无干扰性。在实际实验中，所建议的五轴扫掠扫描路径的机器平移轴的平均切线速度和加速度分别仅为三轴之字形扫描路径的机器的平均切线速度和加速度分别为16.45％和17.19％。当以高扫描速度检查高精度圆柱表面时，在五轴扫描和三轴扫描中，表面轮廓误差的均方根分别为0.002 mm和0.004 mm。