A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The ran...A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The range of target-to-interceptor speed ratio during target interception is derived when guidance laws are applied in high-speed targets interception,and the effectiveness of negative navigation ratio in the PN-based guidance law is proven analytically in some lemmas.Based on the lemmas,the lateral acceleration command of CPN is defined,and the solution to the appearance of singularity in time-varying navigation ratio is given.The simulation results show that CPN can determine headon engagement(as PN) or tail-chase engagement(as RPN) through initial path angle compared with PN and retro proportional navigation(RPN),and can adjust the value of navigation ratio for head-on engagement or tail-chase engagement.Therefore,the capture region of CPN is larger than that of other guidance laws using PN-based methods.展开更多
A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target intercep...A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target interception. BRPN guidance law is defined, and the exact time-varying bias for a required impact angle is derived. Furthermore, the simulation results(trajectory, variation of navigation ratio, capture region, etc) are compared with those of biased proportional navigation(BPN), proportional navigation and retro-proportional navigation. The results show that,at the cost of a higher intercept time, BRPN demands lower terminal lateral acceleration and has larger capture region compared to BPN.展开更多
The capturability of the Three-Dimensional(3D)Realistic True Proportional Navigation(RTPN)guidance law is thoroughly analyzed.The true-arbitrarily maneuvering target is considered,which maneuvers along an arbitrary di...The capturability of the Three-Dimensional(3D)Realistic True Proportional Navigation(RTPN)guidance law is thoroughly analyzed.The true-arbitrarily maneuvering target is considered,which maneuvers along an arbitrary direction in 3D space with an arbitrary but upperbounded acceleration.The whole nonlinear relative kinematics between the interceptor and target is taken into account.First,the upper-bound of commanded acceleration of 3D RTPN is deduced,using a novel Lyapunov-like approach.Second,the reasonable selection range of navigation gain of3D RTPN is analyzed,when the maneuver limitation of interceptor is considered.After that,a more realistic definition of capture is adopted,i.e.,the relative range is smaller than an acceptable miss-distance while the approaching speed is larger than a required impact speed.Unlike previous researches which present Two-Dimensional(2D)capture regions,the inequality analysis technique is utilized to obtain the 3D capture region,where the three coordinates are the closing speed,transversal relative speed,and relative range.The obtained capture region could be taken as a sufficient-but-unnecessary condition of capture.The new theoretical findings are all given in explicit expressions and are more general than previous results.展开更多
目的对1例疑诊德朗热综合征(Cornelia de Lange syndrome,CdLS)的患儿进行致病基因变异检测,明确其发病原因。方法应用高通量捕获测序对CdLS相关致病基因(NIPBL、SMC1A、SMC3、RAD21和HDAC8)进行测序,用Sanger测序验证测序结果以及致病...目的对1例疑诊德朗热综合征(Cornelia de Lange syndrome,CdLS)的患儿进行致病基因变异检测,明确其发病原因。方法应用高通量捕获测序对CdLS相关致病基因(NIPBL、SMC1A、SMC3、RAD21和HDAC8)进行测序,用Sanger测序验证测序结果以及致病基因的家系分析。结果患儿NIPBL基因存在c.6109-1G>A杂合剪接变异,Sanger测序验证结果表明患儿父母均未携带此变异,提示为新发变异,该变异未在HGMD及ExAC数据库收录。根据Human Splicing Finder预测剪接软件,预测该剪接变异将改变NIPBL基因剪接位点,为致病性变异。未发现SMC1A、SMC3、RAD21和HDAC8基因致病性变异。结论NIPBL基因c.6109-1G>A剪接变异可能是该例患儿的发病原因,新变异的检出丰富了NIPBL基因变异谱。展开更多
文摘A new proportional navigation(PN) guidance law,called combined proportional navigation(CPN),is proposed.The guidance law is designed to intercept high-speed targets,which is a common case for ballistic targets.The range of target-to-interceptor speed ratio during target interception is derived when guidance laws are applied in high-speed targets interception,and the effectiveness of negative navigation ratio in the PN-based guidance law is proven analytically in some lemmas.Based on the lemmas,the lateral acceleration command of CPN is defined,and the solution to the appearance of singularity in time-varying navigation ratio is given.The simulation results show that CPN can determine headon engagement(as PN) or tail-chase engagement(as RPN) through initial path angle compared with PN and retro proportional navigation(RPN),and can adjust the value of navigation ratio for head-on engagement or tail-chase engagement.Therefore,the capture region of CPN is larger than that of other guidance laws using PN-based methods.
文摘A new guidance law, called biased retro proportional navigation(BRPN), is proposed. The guidance law is designed to intercept high-speed targets with angular constraint, which can be used for ballistic target interception. BRPN guidance law is defined, and the exact time-varying bias for a required impact angle is derived. Furthermore, the simulation results(trajectory, variation of navigation ratio, capture region, etc) are compared with those of biased proportional navigation(BPN), proportional navigation and retro-proportional navigation. The results show that,at the cost of a higher intercept time, BRPN demands lower terminal lateral acceleration and has larger capture region compared to BPN.
基金supported in part by the National Natural Science Foundation of China(No.12002370)in part by the Hunan Provincial Natural Science Foundation of China(No.2019JJ50736)。
文摘The capturability of the Three-Dimensional(3D)Realistic True Proportional Navigation(RTPN)guidance law is thoroughly analyzed.The true-arbitrarily maneuvering target is considered,which maneuvers along an arbitrary direction in 3D space with an arbitrary but upperbounded acceleration.The whole nonlinear relative kinematics between the interceptor and target is taken into account.First,the upper-bound of commanded acceleration of 3D RTPN is deduced,using a novel Lyapunov-like approach.Second,the reasonable selection range of navigation gain of3D RTPN is analyzed,when the maneuver limitation of interceptor is considered.After that,a more realistic definition of capture is adopted,i.e.,the relative range is smaller than an acceptable miss-distance while the approaching speed is larger than a required impact speed.Unlike previous researches which present Two-Dimensional(2D)capture regions,the inequality analysis technique is utilized to obtain the 3D capture region,where the three coordinates are the closing speed,transversal relative speed,and relative range.The obtained capture region could be taken as a sufficient-but-unnecessary condition of capture.The new theoretical findings are all given in explicit expressions and are more general than previous results.
文摘目的对1例疑诊德朗热综合征(Cornelia de Lange syndrome,CdLS)的患儿进行致病基因变异检测,明确其发病原因。方法应用高通量捕获测序对CdLS相关致病基因(NIPBL、SMC1A、SMC3、RAD21和HDAC8)进行测序,用Sanger测序验证测序结果以及致病基因的家系分析。结果患儿NIPBL基因存在c.6109-1G>A杂合剪接变异,Sanger测序验证结果表明患儿父母均未携带此变异,提示为新发变异,该变异未在HGMD及ExAC数据库收录。根据Human Splicing Finder预测剪接软件,预测该剪接变异将改变NIPBL基因剪接位点,为致病性变异。未发现SMC1A、SMC3、RAD21和HDAC8基因致病性变异。结论NIPBL基因c.6109-1G>A剪接变异可能是该例患儿的发病原因,新变异的检出丰富了NIPBL基因变异谱。
