可重复使用助推器翻转垂降回收研究

Based on the background of rocket booster, a new method of reverse recycling is put forward to avoid the large range adjustment of the initial attitude, save fuel and simplify the design. First of all, based on dynamics modeling, the landing point prediction method based on neural network, and the reduction of placement accuracy of fire engine the most advantage strategy, to the best state into the return flight. Then, the trajectory optimization algorithm combined with PSO initial trajectory generation and Gauss pseudo-spectral method is adopted to study the multi-constraint trajectory optimization of the landing segment. Considering the large external disturbance in the return process, a robust trajectory planning method based on uncertainty is studied. Meanwhile, in order to improve the rapidity of trajectory planning, to realize the online trajectory planning of model or environment mutation, a rapid trajectory planning method based on model prediction and convex optimization algorithm is studied. Third, in order to ensure the return to landing guidance control precision, considering the booster end constraint and the strong disturbance, vertical landing is studied under the constraint of the optimal robust guidance law and the stochastic optimal attitude control law. The control precision of the vertical landing point, speed and attitude of the booster is improved by using the integrated guidance control technology. Finally, the design simulation software platform and uav inverted vertical drop demonstration platform are used to simulate and demonstrate the above methods.

以火箭助推器回收为背景，提出一种全新的翻转回收方式，避免其初始姿态大范围调整，有效节约燃料和简化设计。首先，基于动力学建模，研究基于神经网络的着陆落点预测方法，以及满足落点精度的减速发动机最优点火策略，以最优的状态进入返回飞行过程。然后，采用PSO初始轨迹生成和Gauss伪谱法相结合的轨迹优化算法，研究返回着陆段多约束轨迹优化问题；考虑返回过程中较大的外部扰动，研究一种基于不确定性的鲁棒轨迹规划方法；同时为了提高轨迹规划的快速性，实现模型或环境突变情况下的在线轨迹规划，研究一种基于模型预测和凸优化算法的快速轨迹规划方法。第三，为保证返回降落制导控制精度，考虑助推器末端垂直降落时多约束和强扰动，研究多约束下的最优鲁棒制导律和随机鲁棒优化姿态控制律，同时还采用制导控制一体化技术提高助推器垂降落点、速度和姿态的控制精度。最后，设计仿真软件平台和无人机翻转垂降演示平台，对上述方法进行仿真和演示。

火箭是人类进入太空的主要运输工具，火箭的成功回收和可重复使用能够大大降低航天发射成本，推进航天事业商业化，具有重要意义。本研究提出一种翻转垂降回收方式，首先建立了助推器分离后的运动学和动力学模型，根据此模型在进行实时预测助推器降落点的基础上进行了减速发动机开机点的优化设计，仿真实验验证了提出的基于凸优化的轨迹优化算法对找到最优开机点非常有效。然后对助推器翻转回收过程的轨迹优化问题进行研究，提出了一种基于凸优化算法的快速轨迹规划方法，仿真实验验证了该方法的可靠性和对初值的鲁棒性。本研究还涉及了助推器翻转垂降回收的高精度制导和控制，在多约束和考虑随机干扰的条件下进行了最优鲁棒制导研究以及随机鲁棒优化姿态控制研究，最后设计了制导和控制一体化系统。本研究的内容都是火箭回收过程中亟待解决的关键问题，成果对于成功回收火箭具有重要意义。