Satellite fault diagnosis and fault-tolerant control method based on self-adaptive observer

Abstract

The invention relates to the technical field of satellite fault diagnosis and fault-tolerant control, and proposes a fault diagnosis method, which has very good robustness to external interference, isfree of influence of external interference in a fault diagnosis process, prevents generation of misinformation and missing report, and can effectively estimate fault severity. According to the satellite fault diagnosis and fault-tolerant control method based on a self-adaptive observer, first a satellite kinematics and dynamics model under an actuator fault and external interference influence isestablished to analyze influence of fault effective factors on a system; secondly, an observer is designed for a satellite fault system, a residual error evaluation function is established based on observer output and system actual output, an evaluation threshold value is obtained, and the purpose of fault detection is achieved; then, when occurrence of a fault is detected, a self-adaptive observer is designed to complete a fault diagnosis task; and finally, based on an estimated value of the fault, a finite time self-adaptive fault-tolerant controller is designed. The satellite fault diagnosis and fault-tolerant control method based on a self-adaptive observer is mainly applied to fault diagnosis and fault-tolerant control occasions.

Description

technical field [0001] The invention relates to the technical field of satellite fault diagnosis and fault-tolerant control, in particular to the field of diagnosis and fault-tolerant control for actuator faults in satellite attitude control systems. Specifically, it involves satellite fault diagnosis and fault-tolerant control methods based on adaptive observers. Background technique [0002] A spacecraft refers to a space vehicle that operates outside the atmosphere in accordance with the laws of celestial bodies. After decades of exploration and development, spacecraft technology has played an important role in national security, economic development, technological progress, environmental monitoring, weather forecasting, and disaster reduction and relief. The development of the aerospace industry is not only a manifestation of the progress of aerospace science and technology, but also a manifestation of the continuous growth of a country's comprehensive national strength...

AI Technical Summary

Problems solved by technology

However, when carrying out satellite fault diagnosis and fault-tolerant control design based on existing theoretical methods, the existing deficiencies are mainly reflected in the following aspects: (1) Most researchers mainly focus on satellite linearization models for fault diagnosis research, that is, in small The satellite attitude kinematic equation is linearized under the condition of attitude angle, and then the fault diagnosis and fault-tolerant controller design are carried out for the linearized satellite fault model. However, due to the nonlinearity of different degrees in the actual system, it is easy to cause the linear residual generator The diagnostic performance declines, and even false positives and negative negatives occur; (2) Existing fault diagnosis methods seldom consider the influence of spatial disturbance torque, or directly mix the disturbance torque and fault together for estimation, and cannot realize the fault-interference Effective decoupling, these will greatly limit the fault diagnosis accuracy of the satellite attitude control system, and it is difficult to guarantee the robustness of the fault diagnosis method; (3) Most of the previous work assumes that the system state is known, and the fault form is additive faults, while in satellite nonlinear models with multiplicative faults, the fault diagnosis is more complicated because the fault effects are mixed with the state or input of the system

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