RESUMO
In this paper, we consider the problem of asynchronous estimation in the presence of packet losses for the randomly sampling nonlinear system. Packet losses occur at the control input and at the measurement side. Firstly, the synchronization of the asynchronous sampling system is realized by weighting the state of the adjacent state update points. Secondly, the projection theorem is used to estimate the system state at the sampling time. Due to modeling errors and unmodeled dynamics, obtaining an accurate dynamic model is challenging. Therefore, observation inference based on interpolation techniques is proposed to solve the asynchronous estimation problem. Furthermore, the algorithm is extended to multi-sensor systems to obtain a distributed fusion estimator. Finally, simulation experiments are conducted to validate the effectiveness of the algorithm.
RESUMO
In this study, two nonsingular three-dimensional (3D) guidance strategies to intercept a stationary target with desired impact angles, subject to nonlinear coupled dynamics, field-of-view (FOV) limit and lateral acceleration bounds, are investigated. As a stepping stone, two novel sliding mode surfaces are designed, the convergence and boundedness of the two sliding mode surfaces can guarantee the impact-angle-constrained interception while maintaining the seeker's lock-on condition during the guidance. A novel auxiliary system is also presented to compensate for the effects caused by input saturation. In addition, the analytical achievable impact angles set is presented in terms of the initial engagement condition. Numerical simulations with various constraints, a realistic missile model and comparison study have been considered to show the feasibility and effectiveness of the proposed strategies.