针对载人登月任务中,登月舱上升级从月球表面上升入轨的制导问题,用显式制导法设计一种闭环的制导律。首先对共面发射入轨和异面发射入轨两种情形分别建立模型;然后,假设发动机推力固定,分别推导了显式制导律和基于极大值原理的燃料最优制导律,并进行了对比分析。以阿波罗飞船的参数进行仿真,结果表明显式制导法在综合考虑节省燃料、抗干扰和保证精度等因素后更具有优势,并且能很好地解决小角度异面发射的问题。因此,显式制导法具有更高的可靠性和灵活性,适合工程应用。 In the task of manned lunar landing, the lunar module is upgraded to guide the guidance from the lunar surface to the orbit, and a closed loop guidance law is designed by the explicit guidance method. Firstly, the models of coplanar launch into orbit and out of orbit into the orbit are established respectively. Then, assuming that the engine thrust is fixed, the explicit guidance law and the fuel optimal guidance law based on maximum principle are deduced respectively. Comparative analysis. The simulation with Apollo spacecraft showed that the explicit guidance method is more advantageous when considering the factors such as fuel saving, anti-jamming and assurance accuracy, and can solve the problem of small-angle cross-hatching. Therefore, the explicit guidance method has higher reliability and flexibility, suitable for engineering applications.