复杂铸件的三维测量

3D measurement for complex castings

针对复杂铸件尺寸大,结构复杂,槽、腔多,测量时需兼顾测量效率和槽腔可测性的特点,提出了一种大视场双目光栅测量子系统和小视场光栅测量子系统相结合的立体视觉测量方法。该方法使用前者测量复杂铸件的外部可测部分;使用后者测量复杂铸件的槽腔等被遮挡部分。建立了两个测量子系统的数据拼接模型,给出了数据拼接模型参数的定标方法。最后,通过实验验证了该方法的可行性。实验结果表明:该系统测量数据拼接的均方根误差(RMSE)为0.22mm,满足复杂铸件测量的精度要求。相比传统测量方法,该方法兼顾了测量复杂铸件速度快和可以灵活测量槽腔等被遮挡部分的特点,对工程应用具有实际指导意义。

As complex castings are characterized by larger sizes,complex structures and so many sheltered cavities,it is difficult to measure with higher efficiency and better measurability.Therefore,this paper proposes a stereo vision method combined a large-field binocular measuring subsystem with a small-field grating measuring subsystem.The former was used to measure the outer of the complex castings and the latter was used to measure the cavities of the complex castings.A data registration model for the two subsystems was established and also a method to calibrate the model parameters was proposed.The proposed method was validated by experimental tests.It is proved that the proposed method is suitable for measuring complex castings and the data registration Root Mean Square Error （RMSE） is 0.22 mm.Compared with traditional methods,this method has higher measuring velocity and can measure the complex castings with sheltered cavities.In conclusion,the research has great significance in applications.