Pose Adjustmet Method of Multiple Structured Light Sensors for Complex Profile Measurement

Line structured light sensors are widely used in 3D measurement. To obtain completed results of complex profiles, the measurement system usually needs multiple sensors. Due to the misalignment of the laser plane, the measurement accuracy of overlapped profile is hard to be guaranteed. Therefore, a laser plane pose adjustment method based on 3D target is proposed. Firstly, the laser plane is obtained by fitting the test points whose coordinate values are computed by use of the invariance of cross-ratio principle. After obtaining the coefficient of the corresponding laser plane, the normal vector and the pose of the laser plane can be obtained. In the same world coordinate system, the average distance between measurement points and the fitted laser plane can also be calculated. Whether the laser planes are coplanar can be judged by their included angles and the point-to-plane distances of measured profiles. With these evaluation parameters, the pose of the laser line projector can be adjusted. Finally, the cross section profile of a cuboid and rail is measured. By comparing with the reference value, significant improvement of measurement accuracy can be achieved.