基于FPGA的准直测角系统

为了提高线阵CCD准直测角系统的精度、速度、集成度,以及可靠性,提出一种集成于单片FPGA、光积分时间可自适应调节的片上准直测角系统。以FPGA作为系统处理核心,利用高斯滤波算法对CCD输出信号进行数字滤波,利用边缘自动检测算法获得图像的像元级边界,在此基础上应用多项式插值算法对图像边缘位置进行亚像元细分,最终计算出失准角。利用VHDL语言以及MAX+plus II软件完成了系统设计。系统仿真和实验表明,所设计的片上系统具有高精度、高集成度、高可靠性的特点。

The CCD collimating system based on FPGA aiming to measure angle

In order to improve the precision,speed,integration and reliability of the linear CCD system,which was used to measure angle,a new digital system based on FPGA(as the core of the system and the carrier of digital circuit) was designed.In this system,CCD light integration time could be automatically adjusted according to intensity of illumination.The CCD signal was filtered by gauss filter.Utilizing the characteristic that the grads of grey scale breaks at the edge of image,the pixel edge of image was automatically detected.The detection of the sub-pixel edge of image was fulfilled by the polynomial interpolation algorithm and the angle was calculated.The system was modularly designed with VHDL and MAX plus II software.Simulated and tested,the system is proved to have the characteristic of high precision,speed,integration and reliability.