The powered-descent landing(PDL)phase of the Tianwen-1 mission began with composite backshell–parachute(CBP)separation and ended with landing-rover touchdown.The main tasks of this phase were to reduce the velocity o...The powered-descent landing(PDL)phase of the Tianwen-1 mission began with composite backshell–parachute(CBP)separation and ended with landing-rover touchdown.The main tasks of this phase were to reduce the velocity of the lander,perform the avoidance maneuver,and guarantee a soft touchdown.The PDL phase overcame many challenges:performing the divert maneuver to avoid collision with the CBP while simultaneously avoiding large-scale hazards;slowing the descent from approximately 95 to 0 m/s;performing the precise hazard-avoidance maneuver;and placing the lander gently and safely on the surface of Mars.The architecture and algorithms of the guidance,navigation,and control system for the PDL phase were designed;its execution resulted in Tianwen-1’s successful touchdown in the morning of 15 May 2021.Consequently,the Tianwen-1 mission achieved a historic autonomous landing with simultaneous hazard and CBP avoidance.展开更多
本文分析天基感知与攻防体系下的空间安全飞行器制导、导航与控制(guidance, navigation and control, GNC)技术特点,给出空间安全飞行器GNC系统6项关键技术的内涵、实现方法及工程进展,提出空间安全飞行器GNC技术发展路线,可为未来空...本文分析天基感知与攻防体系下的空间安全飞行器制导、导航与控制(guidance, navigation and control, GNC)技术特点,给出空间安全飞行器GNC系统6项关键技术的内涵、实现方法及工程进展,提出空间安全飞行器GNC技术发展路线,可为未来空间安全领域的发展提供参考.展开更多
基于“嫦娥五号”(Chang’E-5,CE-5)任务高安全性、高可靠性、高复杂度、高自主性的功能以及高实时性、强时序性的需求,开展了导航、制导与控制(Guidance,Navigation and Control,GNC)分系统应用软件高可信研制保障技术研究。针对自然...基于“嫦娥五号”(Chang’E-5,CE-5)任务高安全性、高可靠性、高复杂度、高自主性的功能以及高实时性、强时序性的需求,开展了导航、制导与控制(Guidance,Navigation and Control,GNC)分系统应用软件高可信研制保障技术研究。针对自然语言需求定义方式无法精确描述一些关键复杂时序的问题,在需求分析阶段建立了基于时序安全性属性描述的形式化建模语言模型验证技术,保证了系统时序的安全性;针对人工走查难以发现的代码深层次脆弱性缺陷,在设计编码阶段结合飞行任务剖面提取了程序切片,提高了源代码缺陷定位效率,保障了编码的规范性与软件构件的功能正确性;针对复杂软件的海量测试用例无法快速执行的问题,在确认测试阶段,研究了基于状态图和序列图的测试用例生成方法,搭建了一键测试的自动测试系统,实现了海量测试用例的快速自动执行,有效提升了测试效率与测试覆盖性。通过各阶段地面仿真实验和在轨飞行试验验证,表明所提出的高可信软件研制保障技术方法有效可行。展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.61673057 and 61803028)and the Civil Aerospace Advance Research Project.
文摘The powered-descent landing(PDL)phase of the Tianwen-1 mission began with composite backshell–parachute(CBP)separation and ended with landing-rover touchdown.The main tasks of this phase were to reduce the velocity of the lander,perform the avoidance maneuver,and guarantee a soft touchdown.The PDL phase overcame many challenges:performing the divert maneuver to avoid collision with the CBP while simultaneously avoiding large-scale hazards;slowing the descent from approximately 95 to 0 m/s;performing the precise hazard-avoidance maneuver;and placing the lander gently and safely on the surface of Mars.The architecture and algorithms of the guidance,navigation,and control system for the PDL phase were designed;its execution resulted in Tianwen-1’s successful touchdown in the morning of 15 May 2021.Consequently,the Tianwen-1 mission achieved a historic autonomous landing with simultaneous hazard and CBP avoidance.
文摘基于“嫦娥五号”(Chang’E-5,CE-5)任务高安全性、高可靠性、高复杂度、高自主性的功能以及高实时性、强时序性的需求,开展了导航、制导与控制(Guidance,Navigation and Control,GNC)分系统应用软件高可信研制保障技术研究。针对自然语言需求定义方式无法精确描述一些关键复杂时序的问题,在需求分析阶段建立了基于时序安全性属性描述的形式化建模语言模型验证技术,保证了系统时序的安全性;针对人工走查难以发现的代码深层次脆弱性缺陷,在设计编码阶段结合飞行任务剖面提取了程序切片,提高了源代码缺陷定位效率,保障了编码的规范性与软件构件的功能正确性;针对复杂软件的海量测试用例无法快速执行的问题,在确认测试阶段,研究了基于状态图和序列图的测试用例生成方法,搭建了一键测试的自动测试系统,实现了海量测试用例的快速自动执行,有效提升了测试效率与测试覆盖性。通过各阶段地面仿真实验和在轨飞行试验验证,表明所提出的高可信软件研制保障技术方法有效可行。
