Automatic transformation between water level meter measurement data and altitude on the large-scale physical model

Abstract

The water level is one of the most important physical parameters of the physical model experiment. A large-scale physical model usually has many water level meters, It is an important basis for the accurate simulation of the water level to determine the transformation relationship between those level meters readings and the altitude in the prototype. Based on collimated characteristics of laser and image processing by binarization of gray image and character segmentation, an automatic transformation system was developed to improve transformation accuracy. The main idea is to use laser scanner to build a reference plane, then light illuminates the water level meter, so that the CCD on the top of the water level meter could gather the laser beam and convert light intensity to image signals. With further image processing, such as threshold transformation, the system can get the coordinate of laser center. Due to the fixed relationship between the coordinate and the water level meter measurement data, then the system can found transformation relation between water level meter and altitude automatically. Experiments show that comparing with the manual calibration, relative error of automatic calibration water level meter altitude conversion decreased from ±1.34% to ±0.19%.