Research On Spacecraft Rendezvous And Docking Control Considering Performance Constraints And Trajectory Safety

Spacecraft rendezvous and docking technology is an important space technology and plays a key role in missions such as on-orbit service,manned spaceflight,and establishment of a space station.At present,the technology of rendezvous and docking for cooperative targets in space is very mature both in theory and in engineering.However,with the development of space technology,more and more mission requirements related to non-cooperative targets such as acquisition of failed satellites and space debris,in orbit maintenance of failed spacecraft,acquisition of asteroids and so on are emerging.Autonomous Rendezvous and docking with non-cooperative targets is becoming a new technical requirement.In this context,this paper takes the non-cooperative target as the target spacecraft and the sliding mode control as the basic control method,focusing on the short-range hover control,proximity motion control and final approach target spacecraft control during the process of rendezvous and docking.Aiming at the problem of tracking spacecraft short-range hover control,a linear sliding mode controller is designed based on the sliding mode control theory;in order to constrain the system state during the system convergence process,the attitude and orbit coupling controller is designed by combining the prescribed performance control and sliding mode control methods;in order to reduce the system state convergence time,a finite time convergence performance function is used instead of the traditional performance function.Finally,the simulation results show that the designed controllers achieve the expected results.Aiming at the problem of tracking spacecraft’s proximity motion control,the relevant controllers are designed considering fuel optimization and trajectory safety respectively.In order to reduce the fuel consumption of the tracking spacecraft,the attitude and orbit coupling controller is designed by combining the state dependent Riccati equation(SDRE)with the integral sliding mode control.In order to make the track of the tracking spacecraft safe,a spherical obstacle avoidance area is used to envelope the large flexible accessories of the target spacecraft,and a sliding surface and corresponding controller are designed to meet the safety requirements.Finally,the simulation is used to verify the analysis.Aiming at the control problem of the tracking spacecraft approaching the target spacecraft,an elliptic cissoid obstacle avoidance surface is used to limit the trajectory of the tracking spacecraft,a controller is designed based on the artificial potential function so that it can safely approach the target spacecraft;a new obstacle avoidance model is adopted to relax the requirements for the initial position of the tracking spacecraft.Finally,verify and analyze through simulation.