A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a...A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a target,based on fixed-time sliding mode control theory.Based on the nonlinear method of fixed-time sliding mode control,the performance of the cooperative guidance law remains satisfactory even with large-heading-errors scenarios where the linearization-based approaches might be invalid.By virtue of this law,the attacker pursues the target with the assistance of the protector,which can intercept the defender in the engagement scenario.Furthermore,if the attacker is intercepted by the defender,the guidance law of the protector could guarantee that the protector attacks the target.A robust adaptive term is included in the guidance law to deal with the case of the unknown disturbance upper bound of the defender-target team.Finally,the feasibility of the guidance law is verified by nonlinear numerical simulations,and the superiority of it is illustrated by comparing with the linearization guidance law.展开更多
In this paper both Eulerian and Lagrangian approaches are used on the numericalcomputations of dilute gas-solid two-phase flows. In Eulerian approach the gas flow field in atwo-dimensional tunnel is computed by a gene...In this paper both Eulerian and Lagrangian approaches are used on the numericalcomputations of dilute gas-solid two-phase flows. In Eulerian approach the gas flow field in atwo-dimensional tunnel is computed by a general-used software. From this result the particletrajectory is computed by the model of one-way coupling using the knocking relation obtainedfrom the experiments. The computed result shows good agreement with that produced fromexperimental measurement. In addition, in order to consider the coupling effect between thetwo-phase, a two-way coupling model is also used to compute the particle trajectory, andproduced some useful conclusion. The presented computing program can be used to predictthe trajectory of solid particle in dilute two-phase flow.展开更多
基金supported by the National Natural Science Foundation of China(62273119).
文摘A cooperative guidance law is proposed in a two-ontwo engagement scenario with large-heading-errors by choosing zero-effort miss distance as a sliding surface,which consists of an attacker,a protector,a defender,and a target,based on fixed-time sliding mode control theory.Based on the nonlinear method of fixed-time sliding mode control,the performance of the cooperative guidance law remains satisfactory even with large-heading-errors scenarios where the linearization-based approaches might be invalid.By virtue of this law,the attacker pursues the target with the assistance of the protector,which can intercept the defender in the engagement scenario.Furthermore,if the attacker is intercepted by the defender,the guidance law of the protector could guarantee that the protector attacks the target.A robust adaptive term is included in the guidance law to deal with the case of the unknown disturbance upper bound of the defender-target team.Finally,the feasibility of the guidance law is verified by nonlinear numerical simulations,and the superiority of it is illustrated by comparing with the linearization guidance law.
文摘In this paper both Eulerian and Lagrangian approaches are used on the numericalcomputations of dilute gas-solid two-phase flows. In Eulerian approach the gas flow field in atwo-dimensional tunnel is computed by a general-used software. From this result the particletrajectory is computed by the model of one-way coupling using the knocking relation obtainedfrom the experiments. The computed result shows good agreement with that produced fromexperimental measurement. In addition, in order to consider the coupling effect between thetwo-phase, a two-way coupling model is also used to compute the particle trajectory, andproduced some useful conclusion. The presented computing program can be used to predictthe trajectory of solid particle in dilute two-phase flow.
