俯仰轴轴线位置的视觉标定方法研究

针对气膜孔五轴视觉测量系统中的俯仰轴轴线标定问题,提出了一种应用工业级摄像机和定制的标定靶标来确定俯仰轴轴线的空间位置的新方法.以具有锋利和完整直边特征的长方体金属块作为标定靶标,通过系统中俯仰轴的运动使靶标处于不同的位置和姿态,并由三维运动平台带动摄像机运动,使其对焦于处于不同状态的靶标表面,并采集包含目标棱边的前表...

Research on Vision Calibration Method of the Pitch Axis Position

With regard to the calibration difficulty of pitch axis positions in the five-axis vision measuring system for film cooling holes, a new calibration method based on industrial camera and specially designed target was proposed. During the implementation of the method, a cuboid metal block with sharp and intact edges was applied as the calibration target. In the calibrating procedure, the target was placed at different positions and postures by the rotations of the pitch axis. Afterwards, the industrial camera focused on the surfaces of the target in different situations and then captured the images of the same goal edge on the front surface and upper surface respectively. According to the constraint condition established by the uniqueness of the goal edge extracted from those images, spatial position of the pitch axis in the measuring space denoted by O-XYZ would be calculated by solving simultaneous equations. At last, to verify the calibration method and results, a test piece was measured 10 times by the system after pitch axis position calibration, whose nominal size was 60mm. As shown in the inspecting experiments, the limit errors of single measurement of the length dimension were ±0.0216mm, and the measuring errors of those experimental results were all smaller than ±0.012mm, which manifested the feasibility and effectiveness of the calibration method proposed.