Fringe pattern generation of three-dimensional shape measurement based on FPGA

This paper presents a method about fringe pattern generation of three-dimensional (3D) shape measurement based on field programmable gate array (FPGA). The system hardware is described by logic circuits in Verilog hardware description language (HDL). The system includes signal generation module, signal control module, fringe pattern selection module, video graphics array (VGA) and liquid crystal display (LCD) module. FPGA is used for generating fringe patterns with randomly adjustable frequency, phase and type in the system. Afterward, the fringe pattern is projected onto the object under test by the digital light processing (DLP) projector. The fringe pattern generated by the system is stable and accurate, not affected by the environment and space of measurement. At the same time, it can also make up for the shortcomings of the traditional measurement methods which rely on the computer generating fringe pattern. This method not only cuts down size and cost of the system, but also improves the measurement quality.