惯性传感器地面弱力测量系统热设计

Thermal design of ground weak force measurement system for inertial sensors

为了满足惯性传感器地面弱力测量系统的超高温度稳定性要求,对整个系统进行了热设计。首先,介绍了惯性传感器地面弱力测量系统的结构、敏感结构传热路径和内部热源。其次,根据系统热控指标要求,提出了采用三级热控结构和比例积分微分(PID)控制算法相结合的高精度热控方式,减少温度噪声对惯性传感器探测灵敏度的影响。然后,采用UG/NX软件建立有限元模型,并进行了不同工况条件下的热分析计算,得到了惯性传感器地面弱力测量系统在时域上达到平衡后的温度变化值为(1.2~1.6)×10^(−5)K。最后,将惯性传感器地面弱力测量系统在时域上的温度分布在频域上进行描述,得到惯性传感器敏感结构的温度稳定性结果。分析结果表明,在当前热控措施下,惯性传感器敏感结构的温度稳定性均优于10^(−4)K/Hz^(1/2),满足热控指标需求,热设计方案合理可行。

In order to meet the ultra-high temperature stability requirements of the ground weak force measurement system for inertial sensor,the thermal design of the whole system is carried out.Firstly,the struc-ture of ground weak force measurement system of inertial sensor,heat transfer path of sensitive structure and internal heat source are introduced.Secondly,according to the index requirements of the thermal control of the system,a high-precision thermal control method combining the three-stage thermal control structure and Proportional Integral Differential(PID)control algorithm is proposed to reduce the influence of temperature noise on the detection sensitivity of the inertial sensor.Then,UG/NX software is used to establish the finite element model and carry out the thermal analysis calculation under different working conditions,and the temperature change value of the measurement system in the time domain after equilibrium is(1.2−1.6)×10^(−5)K.Finally,the temperature distribution of the measurement system in the time domain is described in the frequency domain,and the temperature stability results of sensitive structure of the inertial sensor are obtained.The analysis results show that under the current thermal control measures,the temperature stability of the sensitive structure of the inertial sensor is better than 10^(−4)K/Hz^(1/2),meeting the requirements of thermal control indicators,and the thermal design scheme is reasonable and feasible.