Research On Guidance And Control Technology Of Autolanding For Reusable Launch Vehicle

Autolanding of Reusable Launch Vehicle (RLV) is the last part of RLV demonstration and thecritical stage to complete the entire flight mission securitily. And designing of the landing trajectory andhigh-precision trajectory tracking technology are the core technology for autolanding of RLV. Thispaper will address on the desiging of trajectory of autolanding of RLV, guidance law, control law.Firstly, combined with the RLV control requirements in automatic landing section, the design ofthe RLV trajectory in automatic landing section is converted to the mathematical optimization problemwith strictly constrained initial and final values. Then the optimized trajectory in automatic landingsection, which can meet the requirements of dynamic pressure, overload and touchdown speed, isfinally designed, using the trajectory design method base on height profile and the optimizationalgorithm with both ends constrained.Secondly, on the basis of the researches of the robust servo LQR multivariable control theory andthe total energy control method, the pitch rate control law, the total energy control law, and the totalenergy distribution law are designed. Through the coordinated control of the resistance plate channeland the elevator channel, the RLV trajectory tracking and the decoupling control of the airspeed areeffectively achieved, and the demands of the high trajectory tracking and the airspeed control inautomatic landing section are satisfied.Thirdly, according to the requirements of tracking of the RLV landing level-trajectory precisionly,the robust servo LQR multivariable control theory and classical control theory are adopted to design rollangle control law and flight path tracking control law with the aileron as the master channel,andheading calibration control law with the rudder as the master channel. This solve the tracking of RLVautomatic landing lateral trajectory and nose heading alignment problem.Finally, this paper has set up a simulation platform for RLV carried out a autolanding flight of thewhole non-linear process. Simulation results show that the dynamic pressure, overload and thetouchdown speed within reasonable limits during autolanding, and a monte-carlo simulation verifies theguidance and control system robustness for the RLV’s uncertainty of aerodynamic, quality, initialconditions and efficiency of control suface.