基于可编程逻辑电路的相机高精度同步信号研究

Realization of High Precision Synchronous Signal for Camera Exposure Based on Programmable Logic Circuit

摘要:

介绍了一种相机曝光控制实时误差补偿外同步信号产生方法。系统由一系列硬件和软件组成,硬件包括通用GPS接收设备、信号接收整理模块和外同步信号相机电平匹配化模块;软件包括设计在可编程逻辑电路中的外同步信号频率生成与调整模块及外同步信号误差分析与调整模块、外同步信号生成模块及外同步信号相机逻辑匹配化模块。GPS接收设备接收卫星信号并实时输出时间B码,信号接收整理模块将时间B码整理成可编程逻辑器件可以接收的电平信号,可编程逻辑器件通过一系列处理模块生成目标相机的外同步信号,随后外同步信号相机电平匹配化模块将外同步信号整理成相机匹配的电平信号来控制相机曝光。实践证明所提方法可以在不添加额外器件的情况下实现相机曝光时间的实时精确控制,将连续成像的图像序列在时间上的精度从通常的数十微秒级提高到单微秒级。

Abstract:

In this paper, a new generation method of external synchronization for camera exposure control is proposed, which can meet the requirement of real-time error compensation. This system consists of a series of hardware and software. General GPS receiver, receiving and collating signal module and external synchronization signal level matching module belong to the category of hardware. The software includes various modules of external synchronization signal in programming logic circuit, there are generation and adjustment module for frequency, error analysis and adjustment module, the signal generating module and the module of matching with camera logic. The GPS receiver receives satellite signals and outputs B code in real-time, receiving and collating signal module converts the B code into a level signal matching capability of programming logic circuit, synchronous signal of target camera is generated through a series of processing module in programming logic circuit, and then it will be converted into suited signal level to control camera exposure in external synchronization signal level matching module. In practice, the method can realize the precise adjustment of the camera exposure time without adding additional devices. The method improves the accuracy of the time series of the continuous image sequence from dozens of microsecond level to single microsecond level.