多路隔离信号智能测量装置的设计与实现

发布时间：2018-05-26 06:33

本文选题：隔离 + 采集　；参考：《中北大学》2015年硕士论文

【摘要】：在航天测试领域，通过监测并分析各个测量信号数据，工作人员可以深入了解飞行器的各工作环境数据与工作状态，为分析飞行器工作性能与故障检验提供了依据，这些测量参数对后续提高飞行器性能所做的改进设计异常重要。本设计要求采集并存储多路模拟信号与PCM串行数据信号，并且多路信号之间要求彼此隔离，互不干涉，从而得到该飞行器测量所需重要参数。将“信号全隔离”的设计思想应用在课题设计之中，重点对信号和电源这两大部分进行隔离。对于在自检模式下地面测试设备输入或者整机联试模式下系统输出的六路模拟电压速变量信号，使用线性光耦芯片对模拟信号构成光耦隔离电路进行隔离。其中，一路PCM数字量信号与六路模拟电压信号必须隔离，六路模拟信号内部亦彼此隔离。六路模拟电压信号进入测量装置后先经过隔离电路、再由A/D变换与采样数据信息，将其存储于FLASH中。与此同时，PCM数字量码流数据全程存储于FLASH中，并且两组数据互不干扰。对于电源供电模块，课题为测量装置设计了一种智能选择供电的方式，提供了遥测系统外部供电和存储装置自带锂电池供电这两种方法。为了避免诸如落地瞬间或其他突发状况对飞行器造成较大冲击，从而导致系统整体瞬间断电，破坏采集存储装置整个工作过程正常供电的需求，课题除了依靠飞行器遥测系统向其提供二次供电外，特别设计添加了锂电池自供电电源模块。将不带电常开触点信号“控制解保”作为测量装置锂电池自供电模块的工作启动信号，同外部电源供电模块一齐保障了测量装置整体机智能供电切换的实现。为采集飞行器落地瞬间六路电压参数与一路PCM码流数据参数,在电源隔离的同时，拟设计一种基于线性光耦HCNR201和A/D模数转换器ADS8365的新型采集存储测量装置，用于实现六路模拟电压直流信号的采集和PCM数字量信号的接收，并在FLASH中存储有效数据。这里应用光耦隔离芯片HCNR201构成光耦隔离电路用于隔离六路0~5V模拟电压信号，由Xilinx公司生产的FPGA控制A/D模数转换器ADS8365对其采编，采用RS-422异步串行接口电路接收一路PCM数字量码流信号，将模拟量与数字量数据进行数模混合编帧后转存写入FLASH中。文章重点阐述了采集存储测量装置的关键技术解决方案、系统硬件电路设计以及FPGA代码逻辑设计。实际测试所采集的模拟量波形稳定，所存储数据完整可靠。实践证明,该系统可以成功隔离并采集到多路信号,满足设计需求。
[Abstract]:In the field of spaceflight testing, by monitoring and analyzing the data of each measurement signal, the staff can deeply understand the working environment data and the working state of the aircraft, which provides the basis for analyzing the performance and fault inspection of the aircraft. These measurement parameters are very important to improve the design of aircraft performance. This design requires the acquisition and storage of multi-channel analog signals and PCM serial data signals, and the multi-channel signals should be isolated from each other and non-interference with each other, so that the important parameters needed for the aircraft measurement can be obtained. The design idea of "complete signal isolation" is applied to the design of the subject, with the emphasis on the isolation of the signal and the power supply. For the six-channel analog voltage and velocity variable signal output from the ground test equipment input or the whole machine combined test mode, a linear optical coupling chip is used to isolate the analog signal to form the optocoupler isolation circuit. One PCM digital signal must be isolated from the six-channel analog voltage signal, and the six-channel analog signal must also be isolated from each other. The six-channel analog voltage signal enters the measuring device and passes through the isolation circuit first, then transforms and samples the data information by the A / D, and stores it in the FLASH. At the same time, the digital bitstream data is stored in FLASH all the time, and the two groups of data do not interfere with each other. For the power supply module, an intelligent power supply mode is designed for the measuring device, and two methods are provided for the external power supply of the telemetry system and the lithium battery power supply for the storage device. In order to avoid the impact on the aircraft, such as landing moment or other sudden situation, which results in the whole system being cut off in an instant, the demand of normal power supply for the whole working process of the acquisition and storage device is destroyed. In addition to providing secondary power supply to aircraft telemetry system, a lithium battery self-powered power supply module is specially designed. The "control unprotected" signal is used as the working start signal of the lithium battery self-supply module of the measuring device, and the realization of intelligent power supply switch of the whole measuring unit is guaranteed together with the external power supply module. In order to collect the parameters of six voltages and one PCM stream data at landing moment, a novel acquisition and storage device based on linear optocoupler HCNR201 and A / D converter ADS8365 is designed while the power source is isolated. It is used to realize the acquisition of six analog voltage DC signals and the reception of PCM digital signals, and to store effective data in FLASH. In this paper, the optocoupler isolation circuit (HCNR201) is used to isolate six analog voltage signals of 0 ~ 5V, which is compiled by FPGA controlled A / D converter (ADS8365) produced by Xilinx Company. The RS-422 asynchronous serial interface circuit is used to receive one PCM digital bitstream signal, and the analog and digital data are mixed into frames and then transferred to FLASH. This paper focuses on the key technical solution of the acquisition and storage measurement device, the design of the hardware circuit of the system and the logic design of the FPGA code. The measured analog waveform is stable and the stored data is complete and reliable. Practice shows that the system can isolate and collect multiple signals successfully and meet the design requirements.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V416.8

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