Fast Optimization of Constrained Reentry Trajectory
- Paper number
IAC-06-C1.4.07
- Author
Dr. Mingguang Wang, Northwestern Polytechnical University, China
- Year
2006
- Abstract
Although reentry navigation and guidance system of shuttle (the first generation Reusable Launch Vehicle) is successful in past 30 years, the navigation and guidance methods should enable the second generation RLV to accomplish fully autonomous and adaptive reentry flight. One of the key problems is to acquire the optimal trajectory quickly. However, it is not a simple task for the reason that the trajectory optimization involves the solution of a two-point boundary value problem, which is considered to be difficult and usually can’t be fulfilled easily. Traditional trajectory optimization algorithms can not be suitable for the fast optimization task. Recently, many scholars attempt to develop some quick numerical methods for generating the three-dimensional constrained reentry trajectory for RLV and achieve some progress. The objective of this paper is to present a new fast numerical method to generate the three-dimensional constrained reentry trajectory for RLV. This method can be used to design the reference trajectory of autonomous navigation system and emergency reentry. First, a new hypothesis is introduced according to the features of three-dimensional constrained reentry trajectory of RLV. Based on this hypothesis, the reentry dimensionless dynamics and kinematics equations of motion are divided into two sets and only one of those is involved in iterations of optimization algorithm, which reduces the computation labor of numerical methods. Next, different from other numerical methods in which all the control variables are optimized simultaneously, the optimization of the control variables (angle of attack and bank angle) is performed one by one, that is, the direct methods is applied to optimize one control variable, while the indirect methods is used to optimize the other, which improves the efficiency of numerical method greatly. Finally, the simulation results show that the method is able to generate a feasible reentry trajectory subject to all kinds of terminal constraints, control variable and path constraints in about 5 seconds on the desktop computer. The optimal trajectory can be used as reference trajectory of autonomous guidance system.
- Abstract document
- Manuscript document
IAC-06-C1.4.07.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.