Minimum radiative heat-load aerocapture guidance with attitude-kinematics constraints
Minimum radiative heat-load aerocapture guidance with attitude-kinematics constraints
复制标题
具有姿态运动学约束的最小辐射热负荷航空捕获制导
DOI：
--
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
E. Mooij
中科院分区：
文献类型：
--
作者：
E. Zucchelli;E. Mooij
为使有效载荷质量最大化，应采用一种使最终速度增量（ΔV）和总热负荷都最小化的气动捕获轨道。在极高速度下，激波层中高温气体辐射产生的热量超过对流产生的热量。对于某些气动捕获任务，这种热负荷可能比对流热负荷大15倍。因此，在某些情况下对流热负荷可被忽略。经分析证明，使最终ΔV最小化的轨道（即具有完全升力和完全降力指令的“邦 - 邦”轨道）也使辐射热负荷最小化。接下来，介绍一种在姿态运动学有约束条件下规划“邦 - 邦”轨道的新型制导方法。这使得仅需调整一个参数就能实现最优轨道。在所研究的案例中，对于 -6°到 -5°之间的进入角以及大范围的扰动，可确保ΔV值低至100米/秒；采用相同的制导方法，相对于传统的气动捕获制导方法，辐射热负荷可降低多达20%。最后，介绍一种利用预测轨道最终倾角信息的横向制导方法。这种制导方法仅需两次反转就能在倾角要求上达到很高的精度，并且也只需要调整一个参数。根据调整情况，可保证最大倾角误差小于0.1°。
To maximize the payload mass, an aerocapture trajectory should be flown in such a way that both the final ΔV and the total heat load are minimized. At very high velocities, the heating due to radiation of high temperature gases in the shock-layer exceeds the heat due to convection. For some aerocapture missions, such a heat load can be 15 times larger than the heat load due to convection. Thus, convective heat load may in some cases be neglected. It is analytically proven that radiative heat load is minimized by the same trajectory that Minimizes The Final Δ V: a bang-bang trajectory, with full lift-up, full lift-down commands. Next, a novel guidance that plans a bang-bang trajectory with constraints in the attitude kinematics is introduced. This allows for achieving an optimal trajectory with only one parameter to be tuned. For the case studied, values of ΔV as low as 100 m/s can be ensured for entry angles between -6° and -5° and a large spectrum of perturbations; with the same guidance, radiative heat load is reduced by up to 20% with respect to traditional aerocapture-guidance methods. Finally, a lateral guidance that makes use of information on the final inclination of the predicted trajectory is introduced. Such guidance allows for very high accuracy in the inclination requirements with only two reversals, and also requires only a single parameter to be tuned. Depending on the tuning, a maximum inclination error of less than 0.1° can be guaranteed.