Filtering the results of measurements three-dimensional geometry of objects by the phase triangulation method under non-stationary lighting conditions

Abstract

The issues of improving the metrological characteristics of the phase triangulation method for measuring three-dimensional geometry are considered. In practice, external lighting is usually non-stationary, which affects the stability of measurement results. The paper proposes a method for filtering data received by a photodetector during measurements using the phase triangulation method under non-stationary lighting conditions. The method is based on frequency analysis of received data and filtering according to the criterion of the amplitude of the first harmonic in the frequency decomposition of the signal. The proposed method is implemented in the form of an algorithm for filtering the measured point cloud in a measuring complex that implements the phase triangulation method. The proposed method has been experimentally tested. A comparison was made of the filtering results obtained by the developed method based on frequency analysis of received data and the filtering method based on the analysis of amplitude modulation of the signal intensity recorded by a photodetector. Based on the results of a comparative analysis of the results of filtration by two methods, an increased (more than eight times) efficiency of the proposed filtration method was established. The results of the work will be useful in the field of processing and analysis of experimental results and for the development of optical methods for measuring three-dimensional geometry.