Robustness Analysis Related to the Control Design of the SHEFEX-II Hypersonic Canard Control Experiment

Abstract

This paper presents the simulation based robustness analysis w. r. t. parameters and initial conditions, related to the hypersonic flight experiment called SHEFEX-II. The robustness criteria and the parameter limits are obtained from the nominal mission profile, the vehicles configuration, and the results of a previous flight test in 2005. Necessary background knowledge and the nominal mission profile are presented. Simulation results are introduced to define the nominal and the worst case trajectories. Due to the fast changing air density during the reentry flight, simulations with modified initial conditions are used to determine the desired damping. Furthermore, preliminary flight test results are presented and discussed.

Hot Structure Flight Data of a Faceted Atmospheric Reentry Thermal Protection System

“…Another experiment onboard is dedicated to the attitude and roll control during reentry by means of the so-called canards, also shown in Figure 1. The canards are to stabilize the forebody during reentry by damping out rolling, pitching, or coning [12,13]. They are mounted onto the flat surfaces of the canard module that transfers the octagonal forebody shape to the cylindrical rocket modules.…”

“…Taking into account all the experience and collected flight data obtained during the SHEFEX I mission, the test vehicle was redesigned to a similarly faceted, sharp-edged reentry body SHEFEX II and extended by an active control system, which allows for active aerodynamic control during the atmospheric flight segment [12,13]. Unlike the nonsymmetric shape of SHEFEX I that provided natural lift during flight, SHEFEX II has an axis-symmetric shape in order to allow for only the control system to generate lift.…”

Design, Modeling and Analysis of a Sharp-edge Hypersonic Stealthy Re-entry Vehicle

“…In 2012, SHEFEX II has been established, it focuses on hypersonic flight control using steerable canard fins and new TPS concepts. By comparing the results of these two experiments and the results of computer simulations, a lot of researches of sharp-edge re-entry vehicles have been made in aero thermo-dynamics [1][2][3][4], aerodynamics, flight dynamics [5][6][7], flight control, structure design [8,9], subsystem design [10][11][12][13].…”

Main Achievements of the Rocket Technology Flight Experiment ROTEX-T

“…In order to gain flight data in hypersonic flight regimes DLR successfully performed the sharp edged hypersonic flight experiments SHEFEX-I 1 and SHEFEX-II 2,3,4,5 . Compared to SHEFEX-I, which reached Mach numbers up to 6.5, SHEFEX-II achieved a maximum Mach number of 9.3 and was equipped with a higher numbers of sensors including a new type of Flush Airdata Sensing (FADS) system for the sharp edged configuration.…”