In dynamic measurement situations, i.e., if the measurement object and the sensor system move relative to each other, this rigid assignment will not be satisfied.
When using a series of N patterns, triangulation algorithms require temporal consistency of these point correspondences during the period NT = N/ f, where f = T −1 is the projection and recording frame rate. Corresponding points are defined as 2D sensor points that are images of the same 3D object point. In general, well-known algorithms for determining 3D object coordinates by evaluating projected patterns are based on detecting two-dimensional (2D) point correspondences between two cameras or between one camera and the projector 4, 5, 6, 7. In particular, dynamically moving or deforming objects are to be measured. Along with the increased demands on measurement accuracy, in recent years, requirements on measurement speed have also risen, which necessitate high-speed pattern projection and recording and fast computation and evaluation. Years of research and development have shown that the accuracy that can be achieved by such pattern projection systems depends directly on the number N of projected patterns 1, 2, 3.
The simultaneous recording of the pattern(s) that are modulated by the object topography. The (sequential) projection of N ≥ 1 pattern(s) onto the object and Measuring the three-dimensional (3D) topography of macroscopic objects by using structured light requires We show that the proposed technique has several advantages over conventional fringe projection techniques, as the easy-to-build and cost-effective GOBO projector can provide a high radiant flux, allows high frame rates, and can be used over a wide spectral range. Finally, we experimentally verify the theoretical findings. We compare the results with those that were obtained via GOBO projection of phase-shifted sinusoidal fringes.
In a simulation-based performance analysis, we examine the parameters that influence the accuracy of the measurement result and identify an optimal pattern design that yields the highest measurement accuracy. Here, we theoretically investigate the method of GOBO projection of aperiodic sinusoidal fringes. We optimised the first experimental setup that we were able to measure inflating car airbags at frame rates of more than 50 kHz while achieving a 3D point standard deviation of ~500 µm. Aperiodic sinusoidal patterns that are cast by a GOBO (GOes Before Optics) projector are a powerful tool for optically measuring the surface topography of moving or deforming objects with very high speed and accuracy.