运载火箭推进剂温度地面高精度测量系统设计

Design of launch vehicle propellant temperature high-precision measurement system

摘要:

为了满足运载火箭推进剂贮箱温度测量需求,研制了一种铂电阻高精度地面温度测量系统。该系统采用四线制铂电阻Pt100作为温度传感器,使用精密运放产生恒流源驱动铂电阻产生电压,通过仪表放大电路进行信号放大,并选用高精度AD转换器进行信号采集。各路阻值测量电路之间采用隔离设计,降低了通道之间的干扰,提高了测量精度。通过自检设计以及校准设计,提高了测试设备的可靠性及测量准确性。测试结果表明,该测温系统稳定可靠,测量误差小于0.01℃,能够准确测量并记录运载火箭各贮箱推进剂温度变化情况,为火箭加注后采取保障措施提供依据,同时为飞行结果分析提供射前实测温度数据支持。

Abstract:

In order to meet the requirement of temperature measurement of propellant for launch vehicle,a high-precision temperature measurement system based on platinum resistance is proposed. Four-wired platinum resistance is used as the temperature sensor,which is driven by a constant current power supply to generate measure voltage. After instrumentation amplifier, signal is collected by high precision AD. Isolation design is adopted among the measurement circuits, which reduces the interference between channels and improves the measurement accuracy. Through self-checking and calibration design, the reliability and accuracy of the system is improved. The test results show that the temperature measurement system is stable and reliable, and the temperature measurement tolerance is less than 0.01℃. The system record the temperature change of the launch vehicle after propellant filling, and provide the measured temperature data for the analysis of flight results.