Li Zhengwen, Fang Changshuai, Zhang Xiaodong
State Key Laboratory of Precision Measuring Technology & Instruments, Laboratory of Micro/Nano Manufacturing Technology, Tianjin University, Tianjin 300072, China.
Sensors (Basel). 2025 Apr 30;25(9):2843. doi: 10.3390/s25092843.
As a special component, inner-wall-shaped parts with a narrow aperture and large cavity play an important role in the field of industrial manufacturing. It is of great significance to accurately measure the full profile of the inner surface of such parts. Line-structured light scanning is a widely used method for inner wall 3D measurement, which is usually applied to linear scanning measurements of the inner wall of pipe-shaped parts. In view of the structural characteristics of narrow-aperture and large-cavity parts, this article establishes a multi-sensor scanning measurement system based on the principle of line-structured light, which adopts rotary scanning instead of the traditional linear scanning measurement method in the system. Additionally, a calibration method is introduced to resolve the challenges associated with the calibration of rotation axis parameters. Considering the structural constraints in the measurement of narrow-aperture and large-cavity parts, a structural optimization algorithm is designed to enable the sensor to achieve a high theoretical measurement resolution while satisfying the geometric constraints of the measured parts. In order to minimize the size of the sensor, the adjacent sub-sensors in the system are arranged in the form of low overlapping fields of view (FOV). To solve the problem of multi-sensor registration under low overlapping FOV, a calibration method based on the structural characteristics of the measurement system itself is proposed, which realizes low-cost and high-precision calibration of the multi-sensor system. Through the repeatability measurement experiment of the spherical cavity parts, the average measurement deviation of the spherical cavity radius was measured to be 6 μm, and the standard deviation was 11.4 μm, which verified the feasibility of the measurement system proposed in this article. By comparing the system calibration method proposed in this article with existing methods, the measurement accuracy of the system is improved by approximately 80%, demonstrating the effectiveness of the proposed method.
作为一种特殊部件，具有窄孔径和大腔体的内壁形零件在工业制造领域发挥着重要作用。精确测量此类零件内表面的完整轮廓具有重要意义。线结构光扫描是一种广泛应用于内壁三维测量的方法，通常用于管状零件内壁的线性扫描测量。针对窄孔径和大腔体零件的结构特点，本文基于线结构光原理建立了多传感器扫描测量系统，该系统采用旋转扫描代替传统的线性扫描测量方法。此外，引入了一种校准方法来解决与旋转轴参数校准相关的挑战。考虑到窄孔径和大腔体零件测量中的结构约束，设计了一种结构优化算法，使传感器在满足被测零件几何约束的同时，实现较高的理论测量分辨率。为了减小传感器尺寸，系统中相邻的子传感器采用低重叠视场（FOV）的形式排列。为了解决低重叠FOV下的多传感器配准问题，提出了一种基于测量系统自身结构特点的校准方法，实现了多传感器系统的低成本高精度校准。通过对球形腔体零件的重复性测量实验，测得球形腔体半径的平均测量偏差为6μm，标准偏差为11.4μm，验证了本文提出的测量系统的可行性。通过将本文提出的系统校准方法与现有方法进行比较，系统的测量精度提高了约80%，证明了所提方法的有效性。
