Reentry trajectory generation and guidance of space-based hypersonic vehicle

The unpowered reentry guidance of a vehicle is studied based on the method of reference trajectory. The methodology for onboard generation of longitudinal reentry trajectory is described in this work. The constraint nonlinear trajectory design can be turned into one-parameter (bank angle)search issue using this methodology. Furthermore, the space-based hypersonic reentry vehicle guidance is divided into the controls of both the longitudinal and the lateral guidances. The longitudinal reference trajectory is tracked using the Linear Quadratic Regulator (LQR) tracking controller and the lateral trajectory is controlled using a heading error corridor. The numerical simulation has demonstrated that the longitudinal reference trajectory can be quickly generated by the methodology. Moreover, it has also shown that the height tracking error, velocity tracking error and the tracking angle error from the designed LQR tracking controller are less than 1 600 m, 7 m/s and 0.3°, respectively. The lateral trajectory can be controlled by the lateral angle inversion for four times.