To solve the finite-time error-tracking problem in mis-sile guidance,this paper presents a unified design approach through error dynamics and free-time convergence theory.The proposed approach is initiated by establis...To solve the finite-time error-tracking problem in mis-sile guidance,this paper presents a unified design approach through error dynamics and free-time convergence theory.The proposed approach is initiated by establishing a desired model for free-time convergent error dynamics,characterized by its independence from initial conditions and guidance parameters,and adjustable convergence time.This foundation facilitates the derivation of specific guidance laws that integrate constraints such as leading angle,impact angle,and impact time.The theoretical framework of this study elucidates the nuances and synergies between the proposed guidance laws and existing methodologies.Empirical evaluations through simulation comparisons underscore the enhanced accuracy and adaptability of the proposed laws.展开更多
Nerve guidance channels are limited by lack of topographical guidance:Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct en...Nerve guidance channels are limited by lack of topographical guidance:Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct end-to-end suture repair,is possible.The problem arises when there is significant segmental loss,which can occur following trauma as well as oncological procedures.展开更多
Considering the problem that the optimal error dynamics can only converge at the terminal time,an impact angle/time constraint missile guidance law with finite-time convergence is designed in this paper,which is based...Considering the problem that the optimal error dynamics can only converge at the terminal time,an impact angle/time constraint missile guidance law with finite-time convergence is designed in this paper,which is based on the pure proportional navigation(PPN)guidance law and the fast terminal error dynamics(FTED)approach.The missile guidance model and FTED equation are given first,and the dynamic equation of impact angle/time error based on PPN is also derived.Then,the guidance law is designed based on FTED,and the guidance error can converge to 0 in a finite time.Furthermore,considering the field of view constraint,the guidance law is improved by using the saturation function mapping method.Finally,a numerical simulation example is given to verify the effectiveness of the guidance law,which shows that the guidance law proposed in this paper can make the missile quickly adjust to the desired states in advance,and effectively relieve the overload saturation pressure of the actuator.展开更多
This paper considers the simultaneous attack problem of multiple missiles against a maneuvering target. Different from most of the existing literature in which the simultaneous attack problem is formulated as a consen...This paper considers the simultaneous attack problem of multiple missiles against a maneuvering target. Different from most of the existing literature in which the simultaneous attack problem is formulated as a consensus problem of missiles' time-to-go estimates, this paper formulates it as the consensus problem of missiles' ranges-to-go. Based on this strategy, novel distributed guidance laws are proposed to solve the simultaneous attack problem with the target of unknown maneuverability.Adaptive control method is introduced to estimate the upper bound of the target's acceleration. The effectiveness of the proposed guidance laws is verified both theoretically and numerically.展开更多
In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This...In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This paper proposes a novel cooperative mid-course guidance scheme for multiple missiles to intercept a target under the condition of large detection errors.Under this scheme,the launch and interception moments are staggered for different missiles.The earlier launched missiles can obtain a relatively accurate detection to the target during their terminal guidance,based on which the latter missiles are permitted to eliminate the handover error in the mid-course guidance.A significant merit of this scheme is that the available resources are fully exploited and less missiles are needed to achieve the interception mission.To this end,first,the design of cooperative handover parameters is formulated as an optimization problem.Then,an algorithm based on Monte Carlo sampling and stochastic approximation is proposed to solve this optimization problem,and the convergence of the algorithm is proved as well.Finally,simulation experiments are carried out to validate the effectiveness of the proposed cooperative scheme and algorithm.展开更多
基金supported by the National Natural Science Foundation of China(12002370).
文摘To solve the finite-time error-tracking problem in mis-sile guidance,this paper presents a unified design approach through error dynamics and free-time convergence theory.The proposed approach is initiated by establishing a desired model for free-time convergent error dynamics,characterized by its independence from initial conditions and guidance parameters,and adjustable convergence time.This foundation facilitates the derivation of specific guidance laws that integrate constraints such as leading angle,impact angle,and impact time.The theoretical framework of this study elucidates the nuances and synergies between the proposed guidance laws and existing methodologies.Empirical evaluations through simulation comparisons underscore the enhanced accuracy and adaptability of the proposed laws.
文摘Nerve guidance channels are limited by lack of topographical guidance:Treatment of sizeable nerve gaps remains problematic following peripheral nerve injury.Functional outcomes are good when neurorrhaphy,or direct end-to-end suture repair,is possible.The problem arises when there is significant segmental loss,which can occur following trauma as well as oncological procedures.
基金the National Natural Science Foundation of China(No.12002370)。
文摘Considering the problem that the optimal error dynamics can only converge at the terminal time,an impact angle/time constraint missile guidance law with finite-time convergence is designed in this paper,which is based on the pure proportional navigation(PPN)guidance law and the fast terminal error dynamics(FTED)approach.The missile guidance model and FTED equation are given first,and the dynamic equation of impact angle/time error based on PPN is also derived.Then,the guidance law is designed based on FTED,and the guidance error can converge to 0 in a finite time.Furthermore,considering the field of view constraint,the guidance law is improved by using the saturation function mapping method.Finally,a numerical simulation example is given to verify the effectiveness of the guidance law,which shows that the guidance law proposed in this paper can make the missile quickly adjust to the desired states in advance,and effectively relieve the overload saturation pressure of the actuator.
基金supported by the National Natural Science Foundation of China under Grant Nos.61473005,11332001,and 61471242the Research Project Fund under Grant No.17-163-11-ZT-003-018-01+2 种基金the Air Force Advance Research Fund under Grant No.303020503the Joint Fund of Equipment development and Aerospace Science and Technology under Grant No.6141B0624050101the National Defense Basic Scientific Research Program(Major)of China
文摘This paper considers the simultaneous attack problem of multiple missiles against a maneuvering target. Different from most of the existing literature in which the simultaneous attack problem is formulated as a consensus problem of missiles' time-to-go estimates, this paper formulates it as the consensus problem of missiles' ranges-to-go. Based on this strategy, novel distributed guidance laws are proposed to solve the simultaneous attack problem with the target of unknown maneuverability.Adaptive control method is introduced to estimate the upper bound of the target's acceleration. The effectiveness of the proposed guidance laws is verified both theoretically and numerically.
基金partially supported by the National Natural Science Foundation of China(Nos.61333001 and 61473099)
文摘In the interception engagement,if the target movement information is not accurate enough for the mid-course guidance of intercepting missiles,the interception mission may fail as a result of large handover errors.This paper proposes a novel cooperative mid-course guidance scheme for multiple missiles to intercept a target under the condition of large detection errors.Under this scheme,the launch and interception moments are staggered for different missiles.The earlier launched missiles can obtain a relatively accurate detection to the target during their terminal guidance,based on which the latter missiles are permitted to eliminate the handover error in the mid-course guidance.A significant merit of this scheme is that the available resources are fully exploited and less missiles are needed to achieve the interception mission.To this end,first,the design of cooperative handover parameters is formulated as an optimization problem.Then,an algorithm based on Monte Carlo sampling and stochastic approximation is proposed to solve this optimization problem,and the convergence of the algorithm is proved as well.Finally,simulation experiments are carried out to validate the effectiveness of the proposed cooperative scheme and algorithm.