采用精确三维控制场的wMPS全局组网定向方法

Orientation parameters calibration of wMPS by using precise 3D coordinate control network

工作空间测量定位系统是一种基于激光扫描的三维坐标大尺寸分布式测量系统,目前已广泛应用于大尺寸测量领域。该系统可以通过增加发射站数目来扩展量程同时精度并不损失,其前提是有一套精确的全局定向参数。在系统多平面约束的数学模型基础上,阐述了一种基于三维控制场的w MPS全局组网定向方法。在标定空间内设置点位坐标已知的控制点组成控制场,给出了组网定向的模型及优化方法,并给出迭代初值生成方法。实验表明:通过基于控制场全局组网定向方法后,系统与激光跟踪仪对比后点位误差优于0.15 mm,在提高效率的同时大大提高了系统的精度。

The wMPS was a 3D coordinate system based on laser scanning, which was widely applied in large-scale metrology. The orientation parameters calibration was the critical technique of the system as it could solve the problem between the large measurement scale and high accuracy. This paper focused on a novel orientation parameter calibration method by using high precise three-dimensional coordinate control network after the mathematic model of the system was stated. Several calibration points with known coordinates were set in the workspace to establish the precise 3D coordinate control network. After the novel model of orientation parameters calibration had been explained, both calculation method for optimization and the produce of the initial iteration value were given. As indicated by the results of the verifying experiment, the accuracy and efficiency of the orientation calibration could be distinctly improved by using the proposed method. The experimental data show that the 3D coordinate measurement error is less than 0.15mm as a merit of the proposed method.