【作者】 孙春贞；

【导师】 郭锁凤； 黄一敏；

【作者基本信息】 南京航空航天大学 ， 导航、制导与控制， 2008， 博士

【摘要】 重复使用运载器(RLV)在末端区域能量管理与自动着陆段的飞行包线大、飞行状态变化剧烈、动力学特性的不确定性高,且在不同的飞行阶段表现为不同的特性,必须解决飞行过程中的制导与控制问题。本文主要解决重复使用运载器末端区域能量管理(TAEM)与自动着陆段的制导与控制问题。为了提高重复使用运载器制导与控制系统的自主性和鲁棒性,借用混合动态系统的概念,形成了层次化、模块化的体系结构。这种基于功能的系统结构,大大提高了系统的自主性和对不确定性的自主决策能力,使整个系统具有较好的鲁棒性,且容易修改与维护,为模块的扩展打下了基础。利用质点动力学方程在空间上的描述,形成了基于动压剖面的TAEM轨迹设计方法和能量走廊鲁棒性的分析方法。为了提高轨迹剖面对初始条件不确定性的鲁棒性,形成了在线轨迹生成技术相关的概念,分析了在线轨迹生成技术的思想和设计方法。基于动压剖面的轨迹设计方法可以增大积分步长、减小计算时间,提高轨迹设计的鲁棒性能。为了改善重复使用运载器末端区域能量管理段的控制系统性能,给出了基于轨迹线性化的控制系统结构,这种结构包括前馈和反馈控制系统,反馈控制保证系统的稳定性,前馈则可以改善系统的动态性能。采用基于轨迹线性化的控制系统结构,可以改善控制系统的动态性能,提高非线性跟踪能力,既可以满足RLV大飞行包线范围内的稳定性要求,又可以适应RLV高空的低动态特性和飞行状态剧烈变化的特点根据末端区域能量管理飞行任务的要求,给出了完备的能量管理制导方案,并沿轨迹剖面对制导规律进行了设计,并对制导回路的鲁棒性进行了分析。结果表明,这种制导策略可以满足不同的能量情形,完成末端区域能量管理的任务要求,同时为制导系统的工程实现提供了一种简明方法。根据自动着陆段下滑轨迹的特点,给出了基于高度剖面的自动着陆轨迹设计方法,在高度剖面上规划速度剖面,以满足触地速度的要求。为了分析轨迹的特性,给出了自动着陆轨迹鲁棒性的概念和评价方法,对轨迹鲁棒性进行了分析和评价。根据无动力投放自动着陆的任务要求,提出了一种基于在线轨迹生成的制导技术。这种制导技术充分考虑RLV的飞行能力,根据初始状态和末端状态规划轨迹剖面,将轨迹生成与制导策略相结合,形成制导回路,具有较好的自主性、鲁棒性和工程实用性。最后,在半物理实时仿真环境中,进行全飞行过程和无动力投放自动着陆试验的事务性仿真。结果表明全系统任务管理逻辑的正确性、制导策略与控制策略的合理性以及制导规律与控制规律的鲁棒性。更多还原

【Abstract】 For Terminal Area Energy Management (TAEM) and Autolanding of Reusable Launch Vehicle (RLV), the flight envelope is wide, the flight states are variable, and the range of uncertainties is large. RLV shows distinct characteristics in different flight phases, the guidance and control (G&C) problems must be resolved. The thesis aims to resolving G&C problems of Terminal Area Energy Management (TAEM) and Autolanding.In order to improve the autonomy and the robustness, using the concept of hybrid dynamic system, the modularization, hierarchical architecture is built. The hierarchy architecture basing on functions decomposition can enhance the capability to autonomously perform and make decisions when in the presence of uncertainties, and make entire system robust and easy to maintain.The trajectory design method basing on dynamic pressure profile is formed using the nonlinear equations of motion in space, and the method of energy corridor robust analysis is proposed. In order to improve the trajectory robustness to uncertainties of initial states, the correlative concept about online trajectory design is proposed. The idea and design scheme of online trajectory design is analyzed. The trajectory design method basing on dynamic pressure profile can reduce the step of integral and computational time; improve the robust of trajectory design.To improve the performance and robustness of TAEM control system for RLV, the nonlinear tracking control system architecture basing on trajectory linearization is developed. This architecture includes two parts: feed-forward control system and feedback control system, the feedback control system is used to augment the stability and the feed-forward control system improves the transition performance. The control system by trajectory linearization can improve the transition performance, and improve the ability of nonlinear tracking. The control system not only can meet the need of stability in large fligh envelope, but also adapt to the chariacters of slow transition of high attitude and fast flight state varity of entire flight.According to the flight task of TAEM, the energy management scheme is proposed, which is robust. The guidance law is designed along the nominal trajectory profile and the guidance robustness is assessed. The results show that the guidance scheme is robust and full, which can complete the task of TAEM. The guidance loop also provides an approach of realizing guidance system in engineering.According to the characteristics of autolanding trajectory, the trajectory design method basing on altitude profile is proposed. The velocity profile is planned along altitude profile, which makes the touchdown velocity agree with the desired states. In order to assess the trajectory performance, the concept of autolanding trajectory robustness is proposed, and the trajectory robustness is assessed.Adapt to the task of unpowered dropping autolanding, an adaptive guidance technology with online trajectory shaping is developed. This technology takes full advantage of the vehicle’s flight capability; plans trajectory profile between the known initial states and the desired terminal states; combines online trajectory shaping with guidance scheme; creates the adaptive guidance loop.The adaptive guidance system with online trajectory shaping is robust and practical.Last, the hardware-in-loop entire flight simulation and unpowered dropping experimentation simulation are completed. The results show that the mission management is logical, the guidance scheme and control scheme is reasonable, the guidance law and control law is robust.更多还原