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Jia Huang James D. Biggs Yuliang Bai Naigang Cui 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(9):2823-2833
Current control approaches for solar sail station-keeping on libration point orbits have not considered the degradation of the sail’s optical properties. However, significant optical degradation could lead to poor station-keeping performance or even complete failure. This paper presents an integrated guidance and control strategy to address this problem by updating the reference orbit based on in situ estimation. An exponential optical degradation model is incorporated into the solar radiation acceleration model, and an on-line reference orbit update approach is incorporated into the station-keeping, coupled with an active disturbance rejection controller. The reflection coefficient is estimated on-line and the reference orbit is updated discretely when the optical properties have degraded by a prescribed amount. This strategy provides discrete updates to the reference orbits such that the perturbation due to the optical degradation is maintained within a small range. These smaller perturbations can be dealt with by the controller’s robustness and station-keeping can be sustained for long durations even in the presence of large optical degradation. 相似文献
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针对传统飞机飞行控制律参数单目标优化设计不能同时满足多控制指标要求,且还有与飞行品质要求缺乏相关性和物理意义不明确等缺点,提出了一种基于改进多目标进化算法的飞行控制律多目标优化设计方法。该算法引入了决策者的偏好信息,用以指导算法的搜索过程,使算法在决策者感兴趣的区域进行搜索,不但缩小了算法的搜索空间,提高了算法的效率,而且一次运算只求得偏好区域内若干个折衷解,避免了决策者要在众多非劣解中作出困难的选择。在算法中,采用了新的偏好信息给定方法,并提出了一种模拟"投票选举"的偏好信息处理方法,该方法直观简便并易于实现。最后,使用改进的多目标进化算法对某型飞机纵向控制律设计进行数值仿真,结果显示该算法可有效提高控制律优化调参效率,结果满足期望的飞行品质要求。 相似文献
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有效地运用计算机仿真技术,可以减少对物理样机的需求,降低成本,节省时间.在产品开发进程的后期结合最新的设计更改,来进行工装工具的设计制造,消除产品设计变更所带来的昂贵的工具工装的更改.在设计的早期,按照制造装配与维修工作的可操作性要求,进行设计优化和变更,因而能够减少对特殊工具工装的需求. 相似文献
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Robust Design of Supercritical Wing Aerodynamic Optimization Considering Fuselage Interfering 总被引:4,自引:0,他引:4
Robust optimization approach for aerodynamic design has been developed and applied to supercritical wing aerodynamic design. The aerodynamic robust optimization design system consists of genetic optimization algorithm, improved back propagation (BP) neural network and deformation grid technology. In this article, the BP neural network has been improved in two major aspects to enhance the training speed and precision. Uniformity sampling is adopted to generate samples which will be used to establish surrogate model. The testing results show that the prediction precision of the improved BP neural network is reliable. On the assumption that the law of Mach number obeys normal distribution, supercritical wing configuration considering fuselage interfering of a certain aerobus has been taken as a typical example, and five design sections and twist angles have been optimized. The results show that the optimized wing, which considers robust design, has better aerodynamic characteristics. What's more, the intensity of shock wave has been reduced. 相似文献