A Convex Planning Method for Rocket Vertical Landing Trajectory Considering Iterative Compensation of Nonlinear Terms

In this paper, an online trajectory planning method considering iterative compensation of nonlinear terms is proposed for the vertical landing phase mission of reusable rockets. First, the rocket dynamics equation is established in the vertical landing mission context, and the multi-constrained trajectory planning problem model is given. On this basis, the landing trajectory planning problem is convexification and discretized. For the problem of strong nonlinearity, an iterative compensation solution strategy is designed. The iterative solution sequence of the nonlinear term is weighted with the linear speculation sequence as compensation, solving the planning difficulties caused by nonlinearity. Finally, the proposed trajectory planning method is simulated, and the results show that the method can quickly plan the vertical landing trajectory with strong aerodynamic nonlinear disturbance, and has good robustness to initial disturbance, aerodynamic deviation, and atmospheric density deviation.