Research On Graphics Generation And Video Processing Of Integrated Flight Display System Based On FPGA

Cockpit display and control system is an important part of the integrated avionics system. It is one of the most popular technology in the development of the avionics system. According to the current situation and the main problems of the domestic aircraft cockpit display system, a set of practical integrated flight display system is designed in this paper, which uses FPGA as the core unit to complete a variety of functions such as graphics generation and video processing.According to the function and performance requirements of the cockpit display system, firstly,this paper has designed and implemented hardware architecture, internal logic modules and communication mechanism with the display-control computer. Secondly, considering the problems of high resources consuming and bad real-time performance when using FPGA to compute floating-point arithmetic and square root, it researches anti-aliasing generation algorithms of the widely used basic graphics such as straight line, circle and character in the integrated flight display system. By using the multi-bitwidth fixed-point numbers and the thinking of parallel computing from both ends of the straight line to accelerate the generation; based on the approximate distance from the pixel to the ideal curve to assign grayscale and establishing recursion formula to realize the anti-aliasing generation of the circle, which only uses addition and shift operation; to solve the problems of inaccurate grayscale distribution and bad real-time capability in the traditional algorithm for character rotation, an anti-aliasing algorithm that is based on principle of area sampling is proposed, which assigns grayscale according to the four pixels around the neighborhood. In addition,combining with the structural characteristics of the flight instruments, function independent instrument module is designed and hardware generation of flight instrument graphics is implemented.In order to effectively improve the display efficiency and effect of image and video, this paper also studies the image histogram equalization algorithm and the Dark Channel Prior defogging algorithm;and it makes full use of the parallel processing characteristic of FPGA, calculates the data concurrently in the video capture and output stage, builds pipeline to improve the operation speed and the real-time performance of video processing is guaranteed; meanwhile, according to the anti-aliasing method under the natural background, the real-time overlaying between the flight instrument graphics and external video is implemented.Experimental tests and applications show that the integrated flight display system designed in this paper has features like good anti-aliasing effect and high real-time performance, which can meetthe requirements of the cockpit display system on processing effect and processing speed. It can be further applied to the domestic aircraft.