Aiming at the problem that the accuracy and stability of SINS/BDS integrated navigation system decrease due to uncertain model and observation anomalies, a SINS/BDS integrated navigation method based on classified weighted adaptive filtering is proposed. Firstly, the innovation covariance matching technology is used to detect whether there is any abnormality in the system as a whole. Then the types of anomalies are distinguished by hypothesis test. Different types of anomalies have different effects on state estimation. Based on the dynamic changes of innovation, different adaptive weighting methods are adopted to correct navigation information. The simulation results show that this method can effectively improve the fault-tolerant performance of integrated navigation system in complex environment with unknown anomaly types. When both model anomalies and observation anomalies exist, the speed and position accuracy are increased by 42% and 24% compared with the standard KF, 38% and 22% compared with the innovation orthogonal adaptive filtering, which has higher navigation accuracy.

In this article, aiming at the longitudinal dynamics model of air-breathing hypersonic vehicles, a fuzzy-approximation-based prescribed performance control scheme with input constraints is proposed. First, this article presents a novel prescribed performance function, which does not depend on the sign of initial tracking error. And combining prescribed performance control method with backstepping control, the control scheme can ensure that system can converge at a prescribed rate of convergence, overshoot, and steady-state error. In order to solve the problem that backstepping control method needs to be differentiated multiple times, fuzzy approximators are used to estimate the unknown functions, and norm estimation approach is used to simplify the computation of fuzzy approximator. Aiming at the problem of input saturation of actuator in subsystem of air-breathing hypersonic vehicle, the new auxiliary system is designed to ensure the stability and robustness of air-breathing hypersonic vehicle system under input constraints. Finally, the effectiveness of the proposed control strategy is verified by simulation analysis.

In this paper, a new tracking differentiator is proposed based on the inverse hyperbolic tangent function. Due to the complexity of the tracking differentiator and the inaccuracy of tracking accuracy, accurate differential signals cannot be obtained. It is globally asymptotically stable, and its singularities are stable nodes by proper selection of parameters. The inverse hyperbolic tangent acceleration function has strong nonlinear characteristics, simple structure, less parameters and convenient adjustment. The simulation results show that NTTD is not only simple in structure form and relatively less in design parameters, but also has some advantages in tracking precision, response time and filtering ability.

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Abstract-In the process of tracking a maneuvering target, when there is interference, the system parameters and structure will randomly jump. The previous algorithms have less consideration. The thesis applies the structural random jump system theory to the anti-jamming tracking problem of the two sensors, establishes its nonlinear model, completes the algorithm design, and completes the linearization of the nonlinear model. Experimental verification shows that it can effectively solve the problem of stable tracking of the target in the presence of interference and when the two different sensors are switched to each other.