Thermal design of ground weak force measurement system for inertial sensors

In order to meet the ultra-high temperature stability requirements of the ground weak force meas-urement 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) x 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 ob-tained. 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/Hz1/2, meeting the requirements of thermal control indicators, and the thermal design scheme is reasonable and feasible.