An adaptive fault-tolerant control method for a free-floating space manipulator

Abstract

The invention designs a free floating space mechanical arm self-adaptive fault-tolerant control method with specified tracking performance. The method comprises the following steps that firstly, the problem of unknown objects is captured for a free floating space mechanical arm, and a combined body dynamics model and a general mechanical arm joint actuator fault model are established; secondly, aspecified performance function is preset, and an error value is established after the mechanical arm joint angle is subjected to nonlinear mapping; thirdly, an unknown non-linear part in a radial basis function neural network estimation system is introduced; and finally, the self-adaptive law and the self-adaptive controller of the spatial mechanical arm are designed based on a reverse method. Themethod can be used for solving the problem of tracking control of unknown non-linearity and actuator faults after a free floating space manipulator is used for capturing an unknown object to form a combined body.

Description

technical field [0001] The invention relates to an adaptive fault-tolerant control method for a free-floating space manipulator with specified tracking performance, which is mainly applied to the tracking control problem of the joint angle of the manipulator after the free-floating space manipulator captures unknown objects to form a combined body, and belongs to spacecraft control technology field. Background technique [0002] With the development of space technology, various types of spacecraft provide human beings with various services such as navigation and communication. At the same time, the construction of various space stations, telescopes, solar power plants and other large-scale space facilities is also developing. However, after the spacecraft is abandoned due to failure or the end of the mission, it stays in space and becomes space junk, which not only occupies valuable orbital resources, but also endangers the safety of other spacecraft. At the same time, with...

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to propose a self-adaptive fault-tolerant control method for free-floating space manipulators with specified tracking performance, without specific actuators The fault information and the parameters of the nonlinear structure of the system can ensure that the joint angle of the manipulator meets the preset performance of the fault-tolerant control method, which solves the uncertain dynamic model of the free-floating space manipulator after catching unknown objects and the failure of the actuator. The stability of the joint angle of the manipulator when it is affected ensures the fault tolerance and robustness of the system, and ensures that the tracking convergence speed, overshoot and convergence error of the joint angle of the manipulator meet the preset requirements

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