FPGA-based photogrammetric system multi-camera dynamic synchronous exposure circuit and method

Abstract

The invention discloses an FPGA-based photogrammetric system multi-camera dynamic synchronous exposure circuit and method. The circuit comprises a forward channel module, an FPGA processing module, a power supply module and a clock module. The forward channel module provides connection channels for all the cameras and is also connected with the FPGA processing module to transmit the acquired photographing trigger instruction of each camera. The FPGA processing module records the asynchronous time difference of the shutter action of each camera according to the acquired camera photographing trigger instruction and calculates the value of the asynchronous time difference, and delays other trigger signals according to the value of the asynchronous time difference with the last arrived shutter action signal acting as the reference so as to generate the synchronous photographing trigger signal of each camera. The power supply module supplies power to the FPGA processing module. The clock module is configured for providing a high frequency time base clock signal for the FPGA processing module.

Description

technical field [0001] The invention relates to an FPGA-based photogrammetry system multi-camera dynamic synchronous exposure circuit and method. Background technique [0002] If a single digital camera is used as the main sensor for image acquisition in mobile photogrammetry, the acquired digital images have a series of problems such as small image size, large number of images, long processing time, short baseline, and low elevation accuracy. Although some units at home and abroad, such as the Chinese Academy of Surveying and Mapping Sciences, have developed SWDC aerial survey cameras and special wide-angle combination cameras for UAVs, DMC aerial survey cameras in the United States, and UCD aerial survey cameras in Austria, there are still problems such as high price, large size, complex structure, and weight. Heavy and other issues. [0003] The emergence of multi-camera systems has been widely used. Compared with single cameras, multi-camera systems can obtain more accu...

AI Technical Summary

Problems solved by technology

[0004] Traditional synchronization is that multiple cameras use the same synchronization pulse to control simultaneous exposure, without considering the mechanical differences of each camera, and the time and space of the exposure synchronization error of each camera caused by factors such as temperature, humidity and air pressure in a complex working environment. Dispersion, etc., resulting in the synchronous exposure error of this method is about 10mS, and it is impossible to achieve high-precision synchronous exposure within the microsecond level

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