Robust Guidance And Three-dimentional Energy Management Approach For Multi-stage Solid Launch Vehichles In Ascending

Multistage Solid Launch Vehicle(SLV)is widely used in spacecraft launch,rapid strike and long-range delivery missions due to its advantages of simple and reliable engine structure and flexible launch.It has high commercial and military value.Since SLV adopts depletion shutdown mode,and its motion in three-dimensional space has strong nonlinearity,strong coupling and large-scale state change,and there are multi path constraints,multi terminal con straints,engine parameters,aerodynamic coefficients and other uncertainties,which bring many difficulties to complete the flight mission.Aiming at the above problems,this paper takes the ascent stage of multistage SLV as the research object,and studies the robust guidance and three-dimensional energy management methods.The main research work is as follows:In order to reduce the sensitivity of reference trajectory to uncertainties,a three-dimensional multi-objective robust trajectory optimization method based on the inter-stage sensitivity analysis is developed.Considering the uncertainty,an i nter-stage sensitivity analysis method based on Sobol sensitivity analysis is proposed.In this method,the terminal state deviation distributions of each boo ster stage are introduced into the improved performance index,and the calculation method of the terminal state deviation weights is proposed.Then the improved performance index is constructed to achieve the purpose of enhancing the trajectory robustness.In addition,the optimization model is simplified by ignoring the uncertainty with low impact in each booster stage.Based on the interpolation of thin plate spline function for state variables,a trajectory parameterization method for the whole flight pr ocess of multistage SLV is proposed.This parameterization method is combined with polynomial chaotic expansion.By sampling the uncertainty,the original state is e xpanded at the interpolation node,and the expanded states are used to describe the statistical characteristics of state deviations and path constraints.On this basis,when the unpowered flight time between powered stages is a natural number,an adaptive improved NSGA-III algorithm for the hybrid discrete continuous optimization mo del is further proposed to strengthen the optimization ability,so as to achieve an e ffective solution to the robust trajectory optimization problem.In order to overcome the influence of uncertainties such as engine parameters and aerodynamic coefficients,a trajectory tracking method based on differential inclusion stabilization is developed.An adaptive saturation tracking controller based on differential inclusion is proposed to overcome the problems of large observation error and poor compensation effect in the traditional observation compensation method when the uncertainty changes in a large range.A barrier Lyapunov function based on performance preset is proposed to dynamically constrain the boundary of state deviation to improve the convergence speed and accuracy of state deviations.For the differential inclusion system,the concept of Lie boundary and the calcul ation method are proposed in combination with the uncertain boundary to obtain the controller parameters.In order to reduce the loss of control perfor mance caused by the saturation of the compensation terms of angle of attack and sideslip angle,a fixed time adaptive saturation compensator under differential inclusion system is designed to eliminate the adverse effects of saturation.In order to broaden the regulation range of terminal status and improve the terminal altitude control ability,the research on energy management extra and endo the atmosphere is carried out according to the characteristics of depletion shutdown of solid motors.By consuming the residual energy of the engine through three-dimensional space movement,a three-dimensional robust energy management method based on online planning of the residual velocity capability curve of the engine is proposed.The functions between the altitude increment and lateral displacement and the engine residual velocity capability curve are deduced to ensure that the SLV meets the desired altitude requirement at the terminal moment.The path constraints such as overload are transformed into the feasible region of the solution of the residual engine velocity capability curve,so as to meet the path constraints.An extended state observer is designed to estimate the uncertainty to i mprove the guidance accuracy under uncertainty.On the basis of extra atmosphere energy management,a calculation method of compound residual velocity capability curve based on aerodynamic directional decomposition is further proposed.A dynamic pressure constraint trigger judgment function is designed,and the algebraic equation about altitude constraint is reconstructed to meet the dynamic pressure constraint faced by energy management inside the atmosphere.To sum up,this paper has conducted in-depth research on three aspects: offline robust trajectory optimization before launch,robust tracking guidance for reference trajectory and energy management guidance after launch.It makes targeted i mprovements on the related multi-objective optimization,differential inclusion stabilization,energy management and other frontier theories.Through numerical simulation experiments,the proposed method is analyzed and verified.The research results can provide reference for future SLV advanced guidance technology research.