In order to further improve the performance of dual-band infrared and magnetic fusion attitude measurement method, an interactive multi-model extended Kalman filter(IMMEKF) attitude fusion algorithm is proposed to calculate the rotating missile's full attitude angle by using the data collected from dual-band two-axis infrared sensors and three-axis geomagnetic sensor. Four filtering models are used to solve the problem of inaccurate in the single model filtering process. The interactive multi-model (IMM) and extended Kalman filter (EKF) attitude estimation algorithms are combined by the probability density function, and is used to update the model probability in real time. Each model's probability weights are modified to achieve the optimal attitude angle estimation according to the environment. The semi-physical experiments results show that IMMEKF algorithm has higher accuracy and reliability compared with other latest state-of-the-art fusion estimation algorithms under normal infrared and geomagnetic conditions. In the case of infrared or geomagnetic anomalies, only the IMMEKF algorithm can avoid using the affected sensor data and calculate an accurate value of attitude angle. The reliability of the dual-band infrared and geomagnetic combined attitude estimation method is improved, which provides an effective technical implementation for the rotating missile attitude measurement.

With the continuous development of infrared technology and its extensive usage in the military, the infrared radiation attitude measurement technology has received more and more attention. Aiming at the compensation requirement for complex infrared background interference during the rotating missile infrared attitude measurement, the theoretical research on the dual-band infrared rotating missile attitude measurement is carried out. The mechanism and interference characteristics of the earth infrared radiation are analyzed according to the flying missile movement characteristics. The atmosphere propagation in 3 5lm and 8 14lm infrared radiation bands is studied, and the dual-band infrared radiation attitude measurement model is established. Then, the influence of cloud infrared radiation interference on the dual-band infrared radiation sensor is analyzed and a nighttime dual-band infrared radiation attitude measurement difference compensation algorithm is proposed to obtain the compensated attitude angle parameter. The results of semi-physical experiments show that the compensated roll angle error is within 10.60 and the pitch angle error is within 110. The dual-band infrared radiation attitude measurement difference compensation algorithm can effectively eliminate the effects of cloud infrared radiation interference and improve the anti-interference ability of infrared radiation attitude measurement.

Based on the study of earth infrared radiation and further requirement of anticloud interference ability for a spinning projectile’s infrared attitude measurement, a compensation method of cloud infrared radiation interference is proposed. First, the theoretical model of infrared radiation interference is established by analyzing the generation mechanism and interference characteristics of cloud infrared radiation. Then, the influence of cloud infrared radiation on attitude angle is calculated in the following two situations. The first situation is the projectile in cloud, and the maximum of roll angle error can reach ± 20 deg. The second situation is the projectile outside of cloud, and it results in the inability to measure the projectile’s attitude angle. Finally, a multisensor weighted fusion algorithm is proposed based on trust function method to reduce the influence of cloud infrared radiation. The results of semiphysical experiments show that the error of roll angle with a weighted fusion algorithm can be kept within ± 0.5 deg in the presence of cloud infrared radiation interference. This proposed method improves the accuracy of roll angle by nearly four times in attitude measurement and also solves the problem of low accuracy of infrared radiation attitude measurement in navigation and guidance field.

Due to the numerous advantages of dual-band infrared radiation (DBIR) attitude measurement (AM) technology, it has garnered significant attention from industry and academia. However, geometric errors caused by sensor measurement noise, assembly positions, motor interference and other sensor-related commonalities, along with random errors induced by the sensitivity of DBIR characteristics to infrared radiation interference, collectively undermine the reliability of the estimated attitude information. To address this issue, the bidirectional gated recurrent unit (Bi-GRU) and Transformer were combined to assist extended kalman filter (EKF) for DBIR attitude estimation (CBGTE). The core concept involves two aspects: 1) utilizing EKF to mitigate geometric errors during the process of DBIR AM, and 2) combining Bi-GRU and Transformer to aid EKF in compensating for random errors in the measurement process. A semi-physical experimental platform is established to validate the performance of CBGTE. Through experimental validation with real-world data, the proposed CBGTE algorithm has demonstrated significant improvements in accuracy when compared with several state-of-the-art algorithms, achieving roll angle error of ±0.4° and pitch angle error of ±0.2°.