基于FPGA的激光测速系统设计

发布时间：2018-08-04 09:41

【摘要】：无论是在现代的工业生产中还是在前沿的科学技术研究中,高速飞行的物体的初速度测量技术对现代化的发展都有着非常重要的推动作用。对于研究高速飞行物体的运动性能、飞行轨迹以及飞行的姿态等重要特性,测量其初速度具有重要的现实意义。本文立足于传统的激光测距原理之上,对传统的激光测速方法加以优化,开发出了一套反应时间快、测量精度高的激光测速方案,实现了对航天器从发射装置中发射出时的速度测量。针对于测量现场环境所产生的各种噪声,本系统设计采用高灵敏度、高反应时间的光电二极管对激光信号加以采集,同时通过前置放大器和高速比较器对采集到的信号滤波调理,最终能够成功的提取出信号的边沿变化。最后,在采用以FPGA+MCU为核心构架的系统,对信号进行处理,这不仅对测速方案进行了进一步的优化,而且也能够保证系统的测量精度。相对于目前广泛使用的测速系统,本系统的设计不仅提高了速度的测量精度,而且响应速度块,能够在较短的时间内得到航天器的飞行速度。所设计的测速仪调节方便、体积小巧便于携带,非常适合在各种场合进行速度的测量。本课题的研究内容主要从七个方面进行描述,具体如下:(1)对多种测速方法进行了一个简单的分析、比较,包括线圈测速法、雷达测速法、视频摄影测速法、GPS测速法以及激光测速法。着重研究了两种激光测速法。(2)在选定了激光测速的方法后,以此激光测速方法为基础,根据系统的设计要求,对原有的激光测速方法进行优化。(3)对激光接收模块进行设计,光电二极管选用工业级的NJL6201R-1,其响应速度快、性能优越,通过光电二极管转化的电信号通过前置放大器AD8015后再通过高速比较器ADCMP600进行信号的整形。对上述的芯片进行了一个简单的介绍,并且给出了整个模块的电路设计图。(4)高精度计时模块的设计:以FPGA芯片为核心,采用脉冲计数法对航天器经过固定距离的运动时间进行计数。当接收到计数起始脉冲时,FPGA利用其内部的高精度时钟开始计数,直到接收到停止计数的脉冲信号。(5)数据的处理模块的设计:当MCU芯片接收到FPGA计数结束的中断信号后,开始读取FPGA的计数值,依据既定的通信协议接收到数据后,进行数据的处理。(6)无线模块的设计:采用433MHz的无线传输模块,无线传输芯片选择Si4463,当MCU数据处理结束后通过此模块将相关的数据传输给协调器。(7)显示模块设计:一方面通过液晶显示屏LCD1602A显示单片机处理后的速度值,并且可以根据按键来操作以显示存储在flash中的数据;另一方面通过上位机将无线传输模块传送过来的相关数据显示,以方便查看。本课题的激光测速系统,其测量的速度范围为:0.36km/h~3600km/h,系统误差:≤0.5%。
[Abstract]:The initial velocity measurement technology of high speed flying objects has a very important role in promoting the development of modernization, whether in modern industrial production or in the frontier of scientific and technological research. For the study of the important characteristics of high speed flying objects, such as the motion performance, flight trajectory and flight attitude, the initial velocity of the high-speed flying object is measured. In this paper, based on the traditional laser ranging principle, this paper optimizes the traditional method of laser velocity measurement, develops a set of laser velocity measurement scheme with fast reaction time and high measurement precision, and realizes the velocity measurement for the launch of the spacecraft from the launcher. The system uses a high sensitivity, high reaction time photodiode to collect the laser signal. At the same time, through the preamplifier and the high-speed comparator, the signal filtering is adjusted by the preamplifier and the high-speed comparator. Finally, the edge change of the signal can be extracted successfully. Finally, the system using the FPGA+MCU as the core frame is used to signal the signal. In line processing, this not only further optimizes the speed measurement scheme, but also ensures the measurement accuracy of the system. Compared with the current widely used speed measuring system, the design of this system not only improves the accuracy of velocity measurement, but also responds to speed blocks in a relatively short time. The speed meter is easy to adjust, compact and portable, and is very suitable for measuring speed in various occasions. The research content of this subject is described mainly from seven aspects. (1) a simple analysis of various speed measuring methods is carried out, including coil speed measurement, radar velocity measurement, video velocity measurement, and GPS velocity measurement. And laser velocimetry. Two laser velocimetry. (2) based on the method of laser velocity measurement, based on the method of laser velocity measurement, according to the design requirements of the system, the original laser velocity measurement method is optimized. (3) the laser receiving module is designed, the photodiode is selected as the industrial NJL6201R-1, and its response speed Fast, superior performance, through the electric signal converted by photodiode through the preamplifier AD8015 and then through the high speed comparator ADCMP600 to carry out the signal shaping. A simple introduction to the chip is carried out, and the circuit design diagram of the whole module is given. (4) the design of the high precision timing module: the core of the FPGA chip, mining A pulse counting method is used to count the motion time of the spacecraft through a fixed distance. When the counting start pulse is received, the FPGA starts counting with its internal high precision clock until the stop count is received. (5) the design of the data processing module: when the MCU chip receives the interrupt signal at the end of the FPGA count, it begins. Read the value of FPGA, and process the data after receiving the data according to the established communication protocol. (6) the design of the wireless module: using the wireless transmission module of 433MHz, the wireless transmission chip to select Si4463, and transmit the related data to the coordinator through this module after the end of the MCU data processing. (7) the design of the module: on the one hand, through the module design The liquid crystal display screen LCD1602A displays the speed value after the microprocessor processing, and can operate according to the key to display the data stored in the flash; on the other hand, the related data transmitted over the wireless transmission module by the upper computer is displayed to facilitate the view. The speed range of this subject is measured at the speed range of: 0.36km/h~3600 Km/h, system error: less than 0.5%.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN249

【参考文献】