Spacecraft Rendezvous And Docking Control Based On ADRC Technology In The Final Approach Phrase

Spacecraft autonomous rendezvous and docking is a key technology of space station building on low earth orbit, maintenance and capture on orbit, transporting of astronaut and scientific research equipment and logistical supplies which are engineering application in spaceflight field, and also it is the precondition for china to expand of spatial domain. In this paper, we investigated Active Disturbance Rejection Control and parameter optimization of spacecraft autonomous rendezvous and docking in the final approach phrase which coupled position and attitude in detail.Firstly, the relative dynamics model of spacecraft rendezvous and docking in final approach phrase which coupled position and attitude were established. By introducing the concept of spiral movement, the motion of spacecraft in aerospace were simplified as the translational and rotational motion of a rigid body in space which can be expressed by dual quaternion. Defined the geocentric inertial coordinate system, spacecraft body coordinate system and spacecraft relative coordinate system. Based on dual quaternion and the theorem of momentum, the kinematic and dynamic equations of a single spacecraft were given, then the relative coupled dynamics and kinematic equations of the chaser-target spacecraft were derived through the analysis of the spiral movement between the two spacecraft body coordinate system. It also proved that the relative translation velocity and angular velocity between the two spacecraft are coupled with each other.And then, based on the derived relative coupled dynamics, a cascade Active Distance Rejection Control scheme were presented by the application of interference estimation and compensation theory in the presence of parameter uncertainties and external disturbances. Designed the virtual variable to ensure that the output can track the expected value; Extended State Observer provided the estimation of state variables and disturbances (sum of acceleration action) according to the input and output data of the system; Nonlinear State Error Feedback Control Law compensated the actual control volume with the estimated value of total disturbance. Guaranteed the spacecraft relative velocity, position and attitude tracking error converges to desired value in a relatively short period of time. The numerical simulation was carried out by choosing appropriate parameters, and the results show that the desired convergence speed and tracking precision requirements of spacecraft rendezvous and docking in final approach phase can be satisfied by the cascade Active Distance Rejection Controller designed in spacecraft proximity relative velocity and position tracking control, also the control scheme had strong robustness and interference suppression ability.At last, a preliminary study of Active Distance Rejection Control parameters selection and optimization was carried out. Combined the ADRC model of spacecraft rendezvous and docking in final approach phase which coupled position and attitude, considering the factors of input energy, the Integral Time Absolute Error criterion were chosen which added the square of control force and torque in performance indexes and set weights respectively. Simulation results show that, by using particle swarm optimization algorithm, it appeared the local optimal solution and premature phenomenon in the different range of parameters. Therefore, based on the analysis of selection range of parameters and particle velocity will affect the convergence of particle swarm algorithm, using the diversity and ergodicity of chaos variable to make up the deficiency of standard particle swarm optimization algorithm. The simulation results show that the chaos optimization method was effective in ADRC parameters optimization.