Reliability design of POS temperature circuit based on FTA

High precision Position and Orientation System (POS) is important equipment in the airborne remote sensing field. However, the precision of POS is easily affected by temperature. Then it is fairly important to measure temperature information with high reliability and high precision. Aiming at this request, brought up by POS temperature measurement circuit, Fault Tree Analysis (FTA) will be introduced as the core of the analysis and design process. In order to establish the fault tree during the qualitative analysis, “data acquired being faulty” is chosen as the top event. Based on the minimal cut sets concluded from FTA, reliability design, using relevant approaches is implemented to enhance the reliability of the circuit. The reliability prediction of the circuit shows that MTBF improves for more than 10 times, which demonstrates the feasibility and efficiency of FTA and the reliability design. The quantitative analysis of the fault tree calculates the fault probability and probabilistic importance of the minimal cut sets, which provides important information for the fault detection and circuit test. Finally, the result of the constant temperature test of 20°C demonstrates the high reliability and high precision of POS temperature measurement circuit.