Research On Multi-Constraint Ascent Guidance Method Of Solid Launch Vehicle

In order to meet human needs for future space activities,countries around the world are developing launch vehicle technology to adapt to increasingly complex,arduous space exploration and transportation tasks vigorously.As modern space transportation missions place higher requirements,the research of related technologies has become an important research content of aerospace.Rockets can be divided into solid or liquid rockets according to the type of engine.Solid rockets have become an important branch of carrier rockets by their own advantages.In order to enable the guidance system of solid rockets to meet more complex launch tasks and have higher orbit accuracy,It is necessary to study the guidance algorithm of solid launch vehicle.Taking the solid launch vehicle as the research object,this paper deduces the sub-level energy management guidance method based on closed-circuit guidance,the last-stage closed-circuit guidance algorithm based on orbital element iteration,and the last-stage multi-constraint guidance method based on PA,completing the solid rockets’ research on the ascent guidance method.First,the solid launch vehicle and its guidance method are investigated,the energy management method and guidance algorithm of the solid rocket are analyzed,and its research and development status are summarized.The paper gives the commonly used coordinate systems and their conversion relations as the basis of the dynamics mathematical modeling of the launch vehicle’s ascending section;uses the launch inertial system as the reference coordinate system to derive the three-degree-of-freedom dynamics equation of the solid rocket;and carries out the trajectory of the launch vehicle The design is convenient for the research of guidance method.Then,the model of solid rocket energy management is established,the attitude modulation method of excess energy consumption is deduced,and the effectiveness of the energy management method and guidance accuracy are verified through simulation examples.Finally,carry out the research on the multi-constraint guidance method of the all-solid rocket terminal.The thesis designs the guidance method in two ways.One method is based on the principle of closed-circuit guidance,which converts the required speed into the current speed vector that satisfies the number of orbital elements,and uses the speed to be increased as the guidance signal.This guidance method is calculated in real time during the engine working time,and achieves the accuracy of orbiting Guidance method with multiple constraints at the final stage;The other is based on the fixed-point guidance theory.It deduces the connection between the current orbit and the target orbit and combines the energy of the fuel carried by the solid rocket.The guidance command is determined as the ignition time and the orientation of the fixed axis.And in order to meet the constraints of speed or attitude,the energy management method is introduced into it,and the last-stage multi-constraint guidance algorithm with higher orbit accuracy is designed.In order to prove the correctness of the algorit hm,the two algorithms were simulated and verified respectively,and compared and analyzed.