Control Design For The Ascent Phase Of The RLV

With the development of space technology，in order to meet the requirements ofboth civil and military，many new ideas are proposed，and reusable launch vehicle(RLV) is one of them. RLV took off from the ground，when it arrived at the requiredflight speed and altitude，launch payloads，and RLV back to the ground. Launch byRLV is without the limits locations，and with the combined cycle propulsion system，the cost can be reduced significantly.Because of reusable launch vehicle with strong coupling nonlinear characteristicsand flight large envelope，so the controller has a lot of special requirements.Reference winged-cone model proposed by the United States Langley ResearchCenter，model a six DOF simulation system. The aerodynamic parameters obtained byinterpolation，and analyze the aerodynamic characteristics as the preparation for thecontroller design. Through the analysis of the aerodynamic characteristics can befound，along with the increase of speed and altitude，the aerodynamic efficiencydecreases，so combine RCS and aerodynamic surface will be better.Linearizing the RLV by dynamic inverse to obtain a pseudo-linear system，anddesign the controller of aerodynamic surface. Analyze the dynamic performance of thecontroller through the simulation.Design the controller of Reaction Control System (RCS). Modeling RCS，set thesize of the dead zone and the delay. Convert continuous signal to discrete signal byPulse-Width Modulation (PWM). Design compound control law，distributing themoment to aerodynamic surface and RCS and achieved a compound controller.Design controller by gain-schedule method over the entire flight envelope.Selecting the operating point by dynamic pressure and speed，and design controller atoperating points，get the controller parameters at operating points. Achieve thecontroller parameters of non-operating point by interpolation. The dynamicperformance and robustness would be verified by Monte Carlo simulation.