带有入轨姿态约束的迭代制导算法及应用研究

针对需要满足一定入轨姿态约束的发射任务，研究一种带有入轨姿态角约束的迭代制导算法在运载火箭中的应用。该制导算法在传统迭代制导算法的基础上，将控制姿态角的最优解析表达式，通过二阶近似，展开为与时间相关的二次函数，可以同时满足入轨点速度、位置和姿态角约束。阐述了迭代制导的基本原理，给出带有姿态角约束的迭代制导算法的推导公式。在有相同姿态角约束的条件下，该算法能够保证入轨精度,与传统迭代制导算法相当，且对姿态角约束有较好的控制效果，运载能力损失较少。仿真结果表明，该算法对故障工况及不同姿态角约束具有一定的适应能力。

Study on Application of Iterative Guidance Algorithm with Injection Attitude Constraints

In view of a launch mission with injection attitude constraints, the study on the application of the iterative guidance with attitude constraints in a launch vehicle is conducted. Based on the traditional iterative guidance algorithm, this algorithm can satisfy the velocity, position and attitude constraints by extending the expression of the attitude angle to the second-order approximate solution, which is a time-dependent quadratic function. The basic principle of the iterative guidance is described, and the derived formula is presented in detail. Under the same attitude constraints, the algorithm has the same accuracy as the traditional iterative guidance algorithm, and has a better control effect on the attitude angle, while resulting in less payload capacity loss. Numerical simulations demonstrate its adaptability to the fault conditions and different attitude constraints.