基于PXI的液体姿轨控火箭发动机试验测控系统设计与实现

针对液体姿轨控火箭发动机地面试验高精度、高风险和灵活多变的特点，设计研发了一套以PXI （PCI extensions for instrumentation）控制器为主体的发动机试验测控系统.控制系统拥有40路开关量控制能力，综合运用手动、时序和自动控制方式.测量系统拥有120路信号同步采集能力，具备故障诊断功能.测控系统软件使用LabVIEW开发，通用性良好.为增强控制可靠性，设计了面向工艺流程的试验面板，应用嵌入式控制，进行信号多级监测并引入紧急自动关机控制.为提高测量精度，对测量参数进行原位标定，提出了一种改进的干扰消除电路.该系统已多次成功应用于液体姿轨控火箭发动机地面试验，采用的设计方法有效地提高了测控系统的可靠性，测量精度和控制精度分别达到0.5%和0.1ms，能够充分满足多种类型的液体姿轨控火箭发动机对试验测控系统的要求.

Design and implementation of PXI based test measurement and control system for attitude and orbit control liquid rocket engine

According to high accuracy, reliability and flexibility of attitude and orbit control liquid rocket engine ground test, a PXI (PCI extensions for instrumentation) controller based test measurement and control system was designed. The control system could operate 40 valves in manual, sequential and automatic modes. The measurement system could acquire 120 signals synchronously with fault diagnosis. The software was developed with LabVIEW in an ideology of modularization, providing favorable expansibility. A process-oriented panel was designed, and embedded control was integrated into the system to improve the reliability. Besides, the safety of fire test was guaranteed with emergency shutdown. To improve the accuracy, calibration was introduced together with a new impulse damping circuit. The test measurement and control system had been successfully implemented in many ground tests of attitude and orbit control liquid rocket engine. The design methods were proved in efficient enhancement of the expansibility and reliability. The accuracy of measurement and control was 0.5% and 0.1ms, respectively, fully fulfilling the ground test requirement of various attitude and orbit control liquid rocket engines.