摘要
为了完成三维型面的高效扫描测量,将激光测头通过回转台安装在三坐标测量机Z轴的移动末端上,以搭建非接触式的光学坐标测量系统。在被测表面三维点云的创建过程中,需要将激光测头的一维距离值转化为测量点的三维坐标值,为此,提出了基于球面的光束空间矢量标定方法。在标定过程中,通过控制测量机X、Y和Z轴的运动实现测头的标定轨迹,使测头能够采集到球面上的若干测量点,同时记录下各轴的光栅尺读数和测头的输出。然后,应用这些数据和球面的约束方程来建立超定非线性方程组,并采用矩阵最小二乘法求解出测量光束所在直线的单位方向向量。最后,将一个直径已知的金属球作为被测对象,应用所搭建的测量系统在10个不同方位对其直径进行测量,所得结果的测量误差均小于0.05 mm,充分说明了所提出的标定方法的有效性,从而为实现空间自由曲面的精密高效测量奠定了基础。
For the purpose of scanning and measuring 3D surfaces efficiently, a ton-contact optical coordinate measuring system was established by installing a point laser sensor on the mobile terminal of Z axis of a CMM through a probe head. As a result of converting one dimensional distance values of the laser sensor to three dimensional coordinates of the measuring points on the surface, a calibration method of the space vector of laser beam based on a spherical surface was proposed. In the c^libration procedure, the trajectory of the laser sensor can be completed by controlling the movement of ~.＇, Y and Z axes of the CMM and several measuring points on the spherical surface can be collected by file sensor, in which the outputs of the grating rulers and the sensor were all recorded. Based on the above and the constraint equation of the spherical surface, a set of over-determined nonlinear equations was se! up and the matrix least square method was used to solve the unit direction vector of the laser beam. Firally, a sphere with known diameter was measured by the optical coordinate measuring system at 10 different directions. Through calculation, the measuring errors are all smaller than 0.05 mm, which manifests the effectiveness of the calibration method proposed in the paper and lays the foundation of measuring spatial free surfaces rapidly and accurately.
出处
《红外与激光工程》
EI
CSCD
北大核心
2015年第12期3775-3781,共7页
Infrared and Laser Engineering
基金
"高档数控机床与基础制造装备"科技重大专项课题(2013ZX04011031)
关键词
激光测头
光束空间矢量
标定
非接触
point laser sensor
space vector of beam
calibration
non-contact
