Finite-time control method for model-uncertain spacecraft attitude tracking without unwinding

Abstract

The invention discloses a model uncertainty spacecraft unwinding-free attitude tracking finite time control method. The method comprises the following steps that S100, an instruction attitude is input; S200, the attitude tracking error amount between the instruction attitude and the actual attitude is calculated; S300, an attitude error vector is calculated, and a finite time sliding mold surfaceis designed; S400, a spacecraft attitude tracking motion model is established, and an ultra-spiral attitude tracking control law is obtained by adopting an ultra-spiral control algorithm; S500, a controlled spacecraft is controlled by adopting the super-spiral attitude tracking control law; S600, steps from S200 to S500 are repeated till the actual attitude of the spacecraft to be controlled meetscontrol requirements. The spacecraft controlled through the method can track the instruction attitude at high precision under the conditions that rotational inertia is unknown and external disturbance exists. Compared with a traditional self-adaptive attitude control method, the method has the advantages of quickness, disturbance resistance and robustness, and an effective scheme is provided forengineering implementation of attitude tracking control.

Description

technical field [0001] The invention relates to a finite-time control method for non-unwinding attitude tracking of a model uncertain spacecraft, which belongs to the field of automatic control. Background technique [0002] In the existing spacecraft attitude control methods, parametric description methods are often used to express the attitude of the spacecraft, such as Euler angles, quaternions, modified Rodrigue parameters, etc. However, these parametric description methods cannot be global And uniquely describe the complete attitude construction space, it may also cause the unwinding phenomenon of the attitude closed-loop system under the control. The unwinding phenomenon will cause the attitude control task that can be completed with only a small-angle attitude maneuver, but it must be realized through a large-angle attitude maneuver in the opposite direction, causing unnecessary control burden. [0003] At present, two methods are mainly used to avoid the unwinding p...

AI Technical Summary

Problems solved by technology

The existing finite-time attitude control method does not consider the internal uncertainty and external disturbance of the spacecraft system, so the robustness of the control scheme is relatively weak

Many large spacecraft that actually operate in orbit have complex structures, and it is difficult to establish accurate mathematical models

Moreover, service operations such as manipulator movement and propellant transmission on the spacecraft will also cause continuous changes in control input parameters and disturbances, and the uncertainty of the system and the complexity of external disturbances are more significant

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