Rocket sublevel attitude overturning landing online guidance method

Abstract

The invention provides an on-line guidance method for rocket sub-stage attitude overturning landing. The method comprises the steps that S1, a rocket last-stage six-degree-of-freedom landing dynamics model is established; s2, constructing a rocket last-stage six-degree-of-freedom dynamic soft landing trajectory optimization model meeting constraint conditions; s3, non-convex constraints in the trajectory optimization model in the S2 are converted into convex constraints in a linearization mode, and a convex trajectory optimization model is obtained; s4, performing discretization processing on the convex trajectory optimization model in the S3; s5, adding a dynamic slack variable to the linearized dynamic equation in S3; s6, designing a trust region constraint to limit the change range of the reference trajectory; s7, determining an initial iteration reference trajectory; s8, solving a discrete convexity model; s9, repeating the iteration solution in the step S8 to converge the trajectory to an optimal trajectory, and completing trajectory optimization of the sampling points in one guidance cycle; and S10, updating an optimal instruction by using a trajectory optimization result, and directly using the optimal instruction as a guidance signal to finally complete rocket sub-level attitude overturning landing online guidance.

Description

technical field [0001] The invention belongs to the technical field of aircraft guidance, in particular to an on-line guidance method for rocket sub-stage attitude flipping and landing. Background technique [0002] With the development of aerospace technology, reuse has become one of the main development directions of future aerospace transportation systems. At present, the reuse technology of the first sub-stage of the launch vehicle has developed rapidly, but for the higher potential energy rocket sub-stage (such as the rocket final stage), the recovery is more difficult, and its flight profile is quite different from that of the first sub-stage of the launch vehicle. The first-stage vertical power landing stage of a traditional launch vehicle does not require thrust to participate in the attitude control of the aircraft (such as Falcon9). The attitude adjustment is mainly achieved through RCS (Reaction Control System, reaction control system) and grid rudder. Therefore, ...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the deficiencies in the prior art, the inventor has carried out a dedicated research and provided an online guidance method for rocket sub-stage attitude reversal landing based on six-degree-of-freedom sequence convex optimization, based on the traditional three-degree-of-freedom return landing guidance method Attitude variables are introduced above, and the six-degree-of-freedom return landing problem is established, which is used to solve the attitude flipping maneuver problem during the landing process. At the same time, the position, speed, and attitude meet the terminal constraint requirements, thereby completing the present invention

Images