A Neural Network Dynamic Surface Control Method for Underactuated Tether Complex System

Abstract

The invention discloses a neural network dynamic surface control method for an underactuated tether complex system, comprising the following steps: decomposing the captured space tether complex system into an underactuated subsystem Ξ b and full drive subsystem Ξ a , and establish the tethered underactuated subsystem Ξ b and full drive subsystem Ξ a The dynamic model of the underactuated subsystem Ξ b and full drive subsystem Ξ a There is a coupling relationship among them: for the underactuated subsystem Ξ b control, using neural network and PD control to design a virtual control law, constructing the expected augmented tracking trajectory; for the full-drive subsystem with disturbance and limited control input Ξ a , with the expected augmented tracking trajectory as the tracking quantity, the neural network dynamic surface control law is designed. This method can be used to solve the stability control problem of the tether complex in the presence of external disturbance and control input saturation; it can also be used to solve the control problem of the underactuated tether system.

Description

technical field [0001] The invention relates to a neural network dynamic surface control method for an underactuated tether complex system after target capture, belonging to the category of tether spacecraft stability control. Background technique [0002] The tethered spacecraft is a complex system formed by connecting the space platform with the spacecraft and the grabber (flying tongue, flying spear, flying net, etc.) through a light and soft tether. Tethered spacecraft can be used to complete orbital debris (such as space debris, rocket upper stages, etc.) clearance, in-orbit maintenance of failed spacecraft and other space tasks. The above-mentioned tasks need to be performed under the premise that the attitude of the complex system is stable. When the grabber captures the high-speed rotating unstable non-cooperative target and forms a complex, in order to achieve the attitude stability of the complex, the tension control device located on the space platform can be use...

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Problems solved by technology

Mainly focused on the following aspects: 1), Sun Guanghui from Harbin Institute of Technology, etc., and Zhu Zhenghong from York University in Canada designed a fractional order control law to realize the control of the tethered satellite "dumbbell body" underactuated model; 2), Nanjing Wen Hao of the University of Aeronautics and Astronautics studied the stability control of the tethered satellite during the recovery / release process of the electrodynamic tether, and designed the corresponding tether tension control force and current control law, but only considered the tether’s in-plane angle and out-of-plane angle. and the length of the tether, ignoring the attitude of the satellite; 3), the team of Professor Huang Panfeng of Northwestern Polytechnical University studied the stability control of the complex after the tether robot target capture, considering the three-dimensional attitude of the complex after capture , but it assumes that the post-capture complex system is an all-drive system

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