Large Deviation Short Rendezvous Guidance Considering Trajectory Safety

With the increasing complexity and diversity of space missions,some tasks put forward new requirements for the short rendezvous and docking technology.Based on the background of space short rendezvous and docking,this paper studies the close-range guidance section and approaching section,puts forward the safe and short rendezvous strategy of the close-range guidance section and the super-fast and safe rendezvous strategy of the approaching section,realizes the rapidity and safety of the whole rendezvous and docking process.The main tasks are as follows:A joint guidance rendezvous strategy of nominal and modified maneuvering is proposed,which realizes the safety of the terminal trajectory of the short rendezvous of the close-range guidance section under the condition of large deviation.Given the shorter rendezvous time,a nominal guidance strategy considering the propagation of deviation is designed under the condition of small initial deviation and high navigation accuracy.The simulation results prove the passive safety of the whole rendezvous process.Under the condition of large deviation,a midway correction calculation model based on covariance analysis is established.Under the condition of nominal trajectory security,a midway correction rendezvous strategy considering terminal trajectory security is proposed.Under the condition of nominal trajectory insecurity,a joint rendezvous strategy of nominal and modified maneuver is proposed.The numerical simulation results show that the more correction times are,the safer the rendezvous terminal trajectory is.A super-fast bias approximation strategy considering trajectory safety is proposed to realize the super-fast approximation of rendezvous.Based on the analysis of unbiased approximation strategy,the concept of aiming bias point is put forward,the approach strategy is designed,and the aiming bias point is analyzed.In the process of bias approximation,the passive safety of approximation trajectory is analyzed.In order to reduce the orbit deviation in the process of approximation,the corresponding fuzzy controller is designed to ensure the passive safety of bias approximation.Numerical simulations show that the time of approximation rendezvous by bias is about 20% of that by unbiased approximation compared with unbiased approximation,which proves the super-fast of the strategy and the effectiveness of the control method.The automatic generation technology of model frame code based on template is studied,which provides convenience for building a fast and safe rendezvous simulation system.The dynamic calculation module,the guidance module,the guidance control module and the visualization display module of the simulation system of the close-range fast and safe rendezvous are designed.The simulation system is built on SIM simulation platform,and the simulation experiment is carried out.At the same time,in order to solve the repeated compilation of the model frame in the simulation system of close-range fast and safe rendezvous and facilitate the rapid establishment of the simulation model,the automatic generation technology of model frame code based on template is studied,and the model framework code automatic generation software was developed.This paper studies the trajectory design of close-range fast and safe rendezvous,and puts forward the rendezvous strategy,which has certain theoretical significance,and can provide certain reference value for the design of close-range fast and safe rendezvous task.