Spacecraft Formation Orbit Control Based On Second-order Sliding Mode And Prescribed Performance Constraints

Good maneuverability is the premise and guarantee for spacecraft to complete complex tasks and other rapid formation of satellites such as on-orbit maintenance,space observation.It is necessary to further study advanced control methods to obtain the expected control performance.At the same time,with the development of the spacecraft industry,the number of satellites in orbital service is increasing,and the problem of formation flight safety in the orbit control of spacecraft formation is becoming increasingly prominent.Based on the above background,this paper aims at two stages of configuration initialization and maintenance after the launch vehicle reaches the predetermined orbit and releases multiple micro-nano satellites.Considering the improvement of the performance,optimization of the fuel consumption and other performance indicators,anti-collision guidance and rapid maneuver response of the micro-nano satellite formation,.The following issues were studied:Aiming at the problem that sliding mode Chattering affects control precision and controller performance,this paper compares the standard Super-Twisting(ST)and introduces linear compensation to get advanced Super-Twisting(AST)second-order sliding mode controller.Further considering the micro-nano satellite fuel optimization problem,an inverse optimal second-order sliding mode controller combining inverse optimal control and second-order sliding mode control is proposed to optimize the fuel consumption in the control process.A new second-order terminal sliding mode controller(SOTSMC)is designed based on adaptive control to solve the uncertainty control problem of micro-nano satellite system.Then the artificial potential function guidance is combined with the adaptive second-order terminal sliding mode controller to design controller enables the formation to have collision avoidance ability while achieving tasks such as target tracking,configuration initialization and configuration reconstruction.Based on the prescribed performance method,a robust adaptive second-order sliding mode controller(SOSMC)based on homogeneous theory and a robust controller based on backstepping are presented to make the tracking error of the relative orbital dynamics in spacecraft formation system has the desired dynamic performance and steady state accuracy.In addition,the two states of position tracking error and speed tracking error are comprehensively considered,and the second-order sliding mode method is used to realize the full state performance constraint control.Finally,a physical test is carried out using a three-axis stage to verify and analyze the performance of some of the controllers designed above.Combined with numerical simulation and comparison analysis,the AST controller and the robust preset performance controller based on backstep method have good engineering practicability and reliability.The traditional first-order sliding mode can realize obstacle avoidance navigation.The other two adaptive second-order sliding mode controllers need further improvement due to the limitations of hardware conditions,the adaptive links in the controller,and the accumulation of control errors caused by the integral links.