Multidisciplinary Design Optimization of Multi-Stage Launch Vehicle using Flight Phases Decomposition

Abstract

-Optimal design of launch vehicles is a complex multidisciplinary problem. The traditional way to optimize such vehicles is to decompose the problem into the different disciplines and to combine specific solvers and a global optimizer. This paper presents a new MDO method to optimize the configuration of an expendable launch vehicle and describes the application of this method to the design optimization of a small liquid fueled multi-stage launch vehicle. The objective is the payload mass maximization. The proposed bi-level method splits up the original MDO problem into the flight phases and optimizes concurrently the different stages of the launch vehicle. This transversal decomposition allows to reduce the search domain at system-level because the optimization problem at this level is analog to a coordination one. Two formulations of the method are presented and the results are compared to the ones obtained by a standard MDO method.

New multidisciplinary design optimization approaches for launch vehicle design

“…The SWORD method decomposes the optimization problem according to the different flight phases (analogue to the different stages) and optimizes each stage independently. 7 In order to reduce the complexity of the LVD problem, this method transforms the initial large MDO problem into the coordination of smaller ones. In this method, each stage optimization gathers all the different disciplines and is analogue to the optimization of a single-stage-to-orbit launch vehicle, for its considered flight phase (Figure 2).…”

“…The combination of the dedicated initialization process and the use of the Nelder and Mead algorithm allows to greatly improve the efficiency of the SWORD method with respect to the use of only global search algorithm as described in previous work. 1,7 Furthermore, a new specific initialization process has been developed at the subsystem level in order to improve the robustness of the subsystem-level optimization with respect to the system-level instructions.…”

An Optimal Algorithm for Midcourse Guidance Law Under Wind Disturbance

“…Optimal control and estimation theory have been commonly used in the design of advanced guidance systems from the late 1960s [2][3][4][5][6][7][13][14][15][16]. Such approaches have been used to develop tracking algorithms that extract the maximum amount of information about a target trajectory.…”