In-flight Longitudinal Guidance for RLV in TAEM Phase

A longitudinal predictor-corrector guidance algorithm based on online generated dynamic pressure profile without integral deduction and aerodynamic identification is researched for reusable launch vehicle in terminal area energy management phase. The algorithm predicts the range-to-go of the vehicle through the current energy state and the dynamic pressure profile parameter by inquiring the off-line calculated data table, the error of the range-to-go caused by the model deviation is considered in-fight based on the measured flight status information. Ground track range is calculated by ground track parameters. The dynamic pressure profile parameter is updated online due to the error between ground track range and range-to-go, which enables the vehicle to arrive at the approach and landing interface with high precision. The simulation results show that the method improves the efficiency of online trajectory prediction, insensitive to the dispersal of the initial position, and has strong adaptability to model deviation.