9 results about "Spacecraft rendezvous" patented technology

The invention discloses a spacecraft approaching rendezvous guidance method based on limited thrust, and belongs to the technical field of spacecraft guidance. The invention aims to solve the problem that fuel consumption and hardware cost cannot be taken into consideration at the same time in an existing spacecraft short-distance guide section autonomous approaching method. Comprising the steps of calculating a theoretical speed increment of a current task stage; in the execution process of the task stage, the state of the propeller is judged according to a preset period; if the propeller is in the propelling process, the remaining speed increment is calculated by combining the theoretical speed increment and the single-cycle speed increment of the propeller; determining that the propeller is in a non-propelling state until the current residual speed increment is smaller than a set threshold value; the theoretical speed increment is calculated again and compared with a track safety belt threshold value to judge whether the tracking spacecraft exceeds the safety belt range or not, and if yes, the task state is updated, and the propeller is controlled to conduct propelling so as to correct the transfer orbit until the task stage is finished. According to the invention, high-precision guidance control is realized.

The invention discloses a spacecraft rendezvous and docking time synchronization optimization control method based on reinforcement learning, and the method comprises the steps: building a spacecraft six-degree-of-freedom relative motion model which comprises a translation dynamic model based on a Clohessy-Wiltshire equation and an attitude dynamic model based on quaternion; a constrained error space is converted into an unconstrained space through a homeomorphic mapping function, and a tracking error system in a strict feedback form is reconstructed; based on an Actor-Critic reinforcement learning framework, generating an optimal virtual control signal, fusing a time synchronization control item, and forcing synchronous convergence of the position and attitude error in a preset time through a normalized sign function; and performing low-pass filtering estimation on the virtual control derivative by adopting a dynamic surface control technology, generating actual control input meeting the saturation constraint of the actuator in combination with a reinforcement learning framework, and limiting a control input amplitude through a projection operator. According to the method, synchronous convergence of position and attitude errors is realized by combining reinforcement learning and time synchronization control theories.

The invention relates to the technical field of spacecraft control, and provides a spacecraft rendezvous control method based on a disturbance observer and related equipment, and the method comprises the steps: constructing a kinetic model of orbit rendezvous of a target spacecraft at an earth-moon translation point, and designing the disturbance observer based on the kinetic model; defining a cost function based on the system state quantity of the target spacecraft, and constructing an action controller of the target spacecraft according to the cost function; calculating a control interference estimated value of the target spacecraft according to the interference observer, and calculating an optimal control value according to the action controller; and calculating a final control value of the target spacecraft based on the control interference estimated value and the optimal control value, and performing orbit intersection control on the target spacecraft based on the final control value. According to the method, the spacecraft rendezvous control precision can be improved.

The application relates to the technical field of spacecraft control, and provides a spacecraft rendezvous control method based on an interference observer and related equipment, the method comprising the following steps: constructing a dynamic model of target spacecraft rendezvous on a geosynchronous orbit, and designing an interference observer based on the dynamic model; defining a cost function based on system state quantities of the target spacecraft, and constructing an action controller of the target spacecraft according to the cost function; calculating a control interference estimation value of the target spacecraft according to the interference observer, and calculating an optimal control value according to the action controller; calculating a final control value of the target spacecraft based on the control interference estimation value and the optimal control value, and performing orbit rendezvous control on the target spacecraft based on the final control value. The method can improve the precision of spacecraft rendezvous control.

The invention discloses a periodic time-lag sliding-mode control method for a nonlinear spacecraft elliptical orbit intersection system. A nonlinear spacecraft elliptic orbit rendezvous system model subjected to external interference is simplified into a nonlinear periodic system according to reversible linear transformation. On the basis, the nonlinear periodic system is written into a strict nonlinear system matched with interference. A periodic time-lag sliding mode controller with a strict nonlinear system matched with interference is designed by using a periodic time-lag sliding mode control method, and a closed-loop system formed by the strict nonlinear system matched with interference and the controller is stable within a preset true anomaly under the action of the controller. The control design method overcomes the defects that a traditional sliding mode control method of an existing spacecraft elliptic orbit rendezvous system is prone to neglecting control constraints, singularity occurs in preset time control implementation, convergence time depends on an initial value condition, the convergence speed is low, and the traditional sliding mode control method is only suitable for a low-order or single-input system. The problem of spacecraft rendezvous in the preset time is solved.

The application discloses a kind of low-orbit spacecraft's meeting window fast planning method, belong to aerospace field.The application implementation method is: after being applied to the rocket of ground launch reaches the edge of atmosphere, rocket carries out a maneuver, and meets target spacecraft in ascending process.Meeting window for spacecraft meeting target task is obtained.Meeting window fast planning is mainly divided into three steps, first, according to the envelope of rocket shutdown point and pulse size, the ascending reachable range is obtained.Second, the height of this ascending device, the range of the target in the fixed system is used to judge the coarse window.Third, after obtaining the coarse window, the rocket is shot to the target direction, and the shutdown point position in the inertial system is obtained.Based on the point, the Lambert method is used to calculate the velocity increment.If the constraint is satisfied, it is determined that the rocket can meet the target, i.e.the low-orbit spacecraft's meeting window fast planning is realized.The application has the advantages of fast planning speed and strong applicability.

The application discloses a spacecraft rendezvous guidance method based on limited thrust, and belongs to the technical field of spacecraft guidance. The application aims at the problem that the existing autonomous approach method of a spacecraft in a close distance guidance stage cannot simultaneously consider fuel consumption and hardware cost. The method comprises the following steps: calculating a theoretical speed increment of a current task stage; judging a state of a thruster according to a preset period during the execution of the task stage; if the thruster is in a propelling state, calculating a residual speed increment by combining the theoretical speed increment and a single-period speed increment of the thruster; until the current residual speed increment is less than a set threshold value, determining that the thruster is in a non-propelling state; then recalculating the theoretical speed increment, comparing the theoretical speed increment with a track safety belt threshold value, and judging whether a tracking spacecraft exceeds a safety belt range; if yes, updating a task state, and controlling the thruster to perform propelling, so as to correct a transfer orbit, until the task stage is ended. The application realizes high-precision guidance control.

This invention discloses a nonlinear model predictive control method for obstacle avoidance during NRHO rendezvous, belonging to the field of spacecraft rendezvous control technology. Addressing the simultaneous needs of rendezvous mission and dynamic debris avoidance during NRHO rendezvous under a three-body or high-fidelity ephemeris dynamics environment, modeling and control design are conducted within this high-fidelity ephemeris dynamics environment. A three-dimensional mapping method suitable for non-convex obstacle avoidance domains with apertures in three-dimensional space is constructed, mapping the non-convex feasible domain induced by obstacles in the original space to a convex feasible domain in convex space. A nonlinear model predictive control problem with obstacle avoidance constraints is constructed within the mapped space, unifying rendezvous terminal accuracy, control cost, thrust constraints, and obstacle avoidance constraints into a single optimization framework. This achieves unified closed-loop control of rendezvous and docking and dynamic debris avoidance under a three-body or high-fidelity dynamics background.

The application discloses a spacecraft rendezvous and docking method and device based on step-by-step orbit raising phase modulation control, and relates to the technical field of spaceflight. The spacecraft rendezvous and docking method comprises the following steps: determining the coplanar phase difference between a target spacecraft and a visiting spacecraft corresponding to each launch window based on a preset launch window range; determining a phase error reference based on a determination date; determining a target launch window from the preset launch window range based on the coplanar phase difference, the phase error reference and a target phase difference; and launching the visiting spacecraft in the target launch window based on a step-by-step orbit raising phase modulation control strategy. The application solves the technical problem that the launch window cannot be accurately determined in the spacecraft rendezvous and docking task in the related art, resulting in low phase modulation control efficiency.