考虑斜坡约束的固定时间行星软着陆制导律设计  

Fixed-time Planetary Soft Landing Guidance Law Design with Glide-slope Constraint

作　　者：龚有敏 郭延宁[1] 孙悦 马广富[1] 郭敏文[2] 张海博[2] GONG Youmin;GUO Yanning;SUN Yue;MA Guangfu;GUO Minwen;ZHANG Haibo(Department of Control Science and Engineering,School of Astronautics,Harbin Institute of Technology,Harbin 150001,China;Beijing Institute of Control Engineering,Beijing 100094,China)

机构地区：[1]哈尔滨工业大学航天学院控制科学与工程系,哈尔滨150001 [2]北京控制工程研究所,北京100094

出　　处：《宇航学报》2023年第5期699-707,共9页Journal of Astronautics

基　　金：国家自然科学基金(62273118,12150008,61973100,61903032);基础科研项目(JCKY2021603B030)。

摘　　要：针对行星探测动力下降段的反馈制导问题,通过引入斜坡约束对着陆轨迹进行约束,应用滑模控制理论和固定时间控制理论,提出了一种固定时间精确软着陆制导方法。首先,根据斜坡约束,定义了约束边界函数,并利用该函数设计了非线性滑模面,不仅保证了系统状态沿滑模面收敛时是固定时间稳定的,还保证了系统状态不会违反斜坡约束。通过引入光滑连续的切换滑模面,避免了滑模面的奇异问题。其次,设计了固定时间制导律,保证了滑模状态能够在固定时间内收敛到零,利用Lyapunov方法证明了系统的稳定性,并分析了在所设计制导律作用下系统状态不会违反斜坡约束。最后,通过数值仿真算例验证了所提算法的有效性以及鲁棒性。An autonomous obstacle-avoidance fixed-time pinpoint soft landing guidance algorithm is proposed for the powered descent phase of planetary exploration by introducing the glide-slope constraint to constrain the landing trajectory and using sliding mode control theory and fixed-time control theory.Firstly,a constraint boundary function is defined according to the glide-slope constraint,and the nonlinear sliding surface is developed using this function,which not only ensures that the system states are fixed-time stable when they slide along the sliding surface but also ensures that the system state does not violate the glide-slope constraint.By introducing a smooth and continuous switching sliding surface,the singularity problem of the sliding surface is avoided.Next,the fixed-time guidance law is designed to ensure that the sliding surface state can converge to zero within a fixed time,the stability of the system is proved using the Lyapunov method,and the system states do not violate the glide-slope constraint under the action of the designed guidance law is analyzed.Finally,the effectiveness and robustness of the proposed algorithm are verified by numerical simulations.

关 键 词：行星着陆 反馈制导 斜坡约束 滑模控制 固定时间 

分 类 号：V448.2[航空宇航科学与技术—飞行器设计]